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The United States Pharmacopoeia

The United States Pharmacopeia (or to give it its full name, The United States Pharmacopoeia and the National Formulary (USP–NF) is a pharmacopoeia published by the United States Pharmacopoeial Convention. It is the official compendia of the United States of America.

The USP-NF contains monographs and standards for medicines, finished dosage forms, active drug substances, excipients, biologics, compounded preparations, medical devices, dietary supplements, and many other therapeutic goods intended for use in healthcare.

The United States Pharmacopeial Convention (confusingly also called the USP) is the non-profit organization that owns the trademark and copyright to the USP-NF. It is charged with the responsibility for publishing the USP-NF and managing the process of developing official monographs as well as availing official reference standards.

The USP-NF does not enforce any laws – it merely carries official standards developed by the United States Pharmacopoeial Convention for medical articles manufactured and marketed in the United States. Enforcement is caried out by the U.S. Food and Drug Administration (FDA).


History of the United States Pharmacopoeia

The United States Pharmacopeia traces its origins to the early part of the 19th century. The War of Independence (1775-1783) had exposed the inadequacy of existing standards in controlling medicines required to meet the needs of American military hospitals.

Leading physicians of the time begun collating information on medicinal products and organising it into dispensatories and pharmacopoeias. In 1820, a group of 11 physicians met at the US Capitol in Washington DC, the result of which was the creation of the first United States Pharmacopeia (published as The Pharmacopoeia of The United States of America).

The first editions were very basic, and aimed only to serve as “authoritative” resources for the public to consult. They included a few hundred products that were deemed well understood and characterised at the time.

In 1848, the US Congress passed the Drug Importation Act in response to public outcry about imported patent medicines from Europe, which many felt substandard. This act recognised the United States Pharmacopeia as the official compendia for the United States of America.

Independently of the United States Pharmacopeia, the American Pharmaceutical Association established the National Formulary (NF) in 1888. The NF principally aimed to serve as a resource and a formulary for small-scale compounding of medicines.

In 1906, the Pure Food and Drugs Act further codified the United States Pharmacopeia and National Formulary standards, recognising both compendia for product strength, quality and purity. Subsequent legislation, including the 1938 Federal Food, Drug and Cosmetic Act, further cemented the role of these compendia in standardisation of quality of medicines in US commerce.

In 1975, the United States Pharmacopoeial Convention purchased the right to the National Formulary, bringing together the two compendia under one roof, thus creating the United States Pharmacopoeia-National Formulary that we know today.


Organisation of the United States Pharmacopoeia

Over the years, the USP-NF has evolved, not just in terms of national and international recognition but also in the scope of the information it covers.

Now in its 43rd edition (from May 2021), the current USP-NF remains true to its original mandate: to be an accessible source of information for quality of prescription, nonprescription, and compounded medicines; excipients; biologics; medical devices; and dietary supplements.

Actives are generally featured in the United State Pharmacopoeia section while excipients appear in the National Formulary. If an excipient is also used as an active it will be featured in the United States Pharmacopeia section.

It features close to 5000 monographs, of which there are around 1500 monographs for active ingredients, 450 for excipients, and over 2500 for finished dosage forms.

In addition to monographs, the USP-NF also features 350 “General Chapters” sections, which covers information on assays, tests, and procedures used in monographs.


Available Formats

The print version of the USP-NF is no longer available. The only available format now is online via a subscription.

The online format is highly convenient not only because of the convenience of access but any updates are automatically posted.

The online format also offers improved search functionalities, and moreover you can set alerts as well as bookmarks for pages of interest.


Subscriber Resources



Brinckmann R. M et al (2020). Quality Standards for Botanicals — Legacy of USP’s 200 Years of Contributions. HerbalGram (American Botanical Society) 126: 50-65. Accessed 10.11.2021.


The European Pharmacopoeia

The European Pharmacopoeia (Ph.Eur) is a pharmacopoeia published by the European Directorate for the Quality of Medicines and Healthcare (EDQM) under the auspices of the Council of Europe and all the signatory states to Treaty Number 050. The Ph.Eur is the de facto official pharmacopoeia of the European Union.

Through its monographs and general chapters, the Ph.Eur fosters public health by elaborating and communicating scientifically-valid standards required for assessing and controlling quality of medicines and excipients.

The European Pharmacopoeial Commission is the decision-making body at the EQQM responsible elaboration and maintenance of the Ph.Eur content, including revision and updates of different monographs and general chapters.


History of the European Pharmacopoeia

The Ph.Eur traces its origins to 1963, when the Public Health Committee of the Council of Europe adopted a draft Convention that lay the legal, technical and administrative foundations of the Ph.Eur. The following year, the Committee of Ministers adopted the Convention and the Rules of Procedure that would govern the European Pharmacopoeia Commission.

Between 1965 and 1966, a Technical Secretariat was expanded and a Commission appointed. Three years later, the first edition of the Ph.Eur was published, and contained just over 100 monographs. Six years later in 1975, the European Union adopted Council Directive 75/318/EEC, which made compliance with Ph.Eur monographs mandatory when applying marketing authorisations.

Now in its 10th edition, the Ph.Eur as well as the Convention has 39 signatory parties from across Europe, including the European Union, that participate and vote on sessions of the European Pharmacopoeia Commission.


Legal Framework

Several regulations form the legal basis for the Ph.Eur. They are:


Organisation of the European Pharmacopoeia

The Ph.Eur is arranged into different sections, including

  • General Chapters
  • General Monographs
  • Monographs for Vaccines, Immunosera, Radiopharmaceuticals, Sutures, Herbal products and Homeopathic products
  • Specific monographs on Active Pharmaceutical Ingredients and Excipients, and
  • Specific Monographs on Dosage Forms

The 10th Edition of the Ph.Eur (including Supplement 10.5) contains 2447 monographs (including dosage forms), 378 general texts (including general monographs and methods of analysis) and about 2800 descriptions of reagents.

All these standards are designed to meet the information needs of scientists and managers involved in research and quality control of medicines, regulatory authorities and those involved in the manufacture of medicinal products or individual components.


Available Formats

The Ph.Eur is available as a single reference volume that covers all relevant articles featured. The 10th Edition was released in July 2019 and will be updated with eight periodic supplements over the following three years (10.1 to 10.8).

Available in either English or French, the print version contains a subscription key (EPID code) that allows access to online archives. The compendium can also be accessed online via a licence (individual or shared access).


Subscriber Resources

The 2021 subscriptions to the European Pharmacopoeia Supplements 10.3-10.5 are available on the EDQM WebStore.



The European Medicines Agency: European Pharmacopoeia

Quality standards of the European Pharmacopoeia


6 Simple Tips for Compelling Scientific Presentations in 2022

Eric Monlin | Public Speaking Coach & Founder, Public Speaking Inc., New York

The twenty-first century is a century of ideas, and ideas, when effectively packaged and delivered, are changing the world. Some people are exceptionally good at presenting their ideas. They have the skill that elevates them and gives them influence over their peers and society. As scientists, we all have ideas and passions, and yearn to inspire others. So, wouldn’t be amazing if we can identify the exact techniques used by the world’s greatest communicators, and apply their secrets to wow our audiences? In this article, I provide insights, based on personal research of hundreds of TED presentations, direct interviews with speakers and personal experience from years of coaching ordinary leaders and speakers over a 20 year period, to help you speak with confidence and authority, whether it is delivering presentation at your company, or a major scientific conference.

The anatomy of great presentations

In 2012, civil rights lawyer Bryan Stevenson gave a talk to an audience of 1,000 people in California. He received a standing ovation and his TED talk has been viewed online over one-and-half million times. For around twenty minutes, Stevenson captivated his audience by appealing to their heads and hearts. At the end of the talk, the attendees donated a total of $1 million to his charity, The Equal Justice Initiative. That’s equivalent to $50,000 for each minute he spoke!

What is remarkable is that Mr. Stevenson did not use any Power Point, visuals or props. It was only through the power of his narrative that carried the moment. I am sure you have viewed other riveting presentations. Some of these were probably backed by engaging slides and graphics. What is clear that there are many ways to share ideas. Some speakers tell stories, and others provide rich data. Great speakers are entertaining, captivating and inspiring; they understand the science and art of persuasion.

The late Steve Jobs, Apple cofounder and technology visionary is famous for his presentation skills. His iPhone launches and commencement speech at Stanford University in 2005 show his ability to captivate audiences. It is little wonder that CEOs everywhere have now adopted Steve Jobs methodology.

Dale Carnegie – The Art of Public Speaking

A key starting point for students of public speaking is Dale Carnegie self-help book, The Art of Public Speaking, first published in 1915. Dale Carnegies recommended that speakers keep their talks short. He said stories where powerful ways of connecting emotionally with audiences, and suggested the use of rhetorical tools such as metaphors and analogies. He understood the role of enthusiasm, practice, and strong delivery to touch people.

Now, while everything Carnegie recommended over 100 years ago remains true today and is the foundation of effective communication today, he did not have the tool we have today. Today’s speakers have Power Point, video and the internet.

We’re all Salespeople

It also is the case that the most effective speakers have understood the knack of getting their ideas to stand out in a sea of noise. Effective salespeople are good at inspiring potential buyers. This is the same blueprint if you want to be an effective speaker. You need to learn how to sell yourself and your ideas more persuasively. If you can’t inspire anyone else with your ideas, it doesn’t matter how great your technology is – there will be no takers!

What makes a presentation compelling?

All great and inspiring talks have three components:

  • Emotion-they touch hearts
  • Novelty-they reveal something new
  • Memorable-they present content in ways people never forget


Great communicators reach heads and touch hearts. The problem with the majority of us (especially within the sciences) is that we forget the ‘heart’ bit. We therefore need to learn how to identify our passions and use them in our stories, thereby creating deeper connections with audiences.


Novelty is one of the most effective way to capture a person’s attention. Humans, it seems, are hardwired to give attention to new things. Research released by YouTube Trends has shown that content that is truly unique and unexpected gets noticed on the platform. Thus, a key aspect of effective communication is engaging audiences is to give them new perspectives, the wow moments.


What’s the point of sharing great ideas if nobody remembers what you spoke about the moment you hand over the microphone? Research shows that to be memorable, a presentation has to be of an ideal length of time, and has to create vivid, multisensory experiences that allow the audience to recall the information successfully.

Here are 6 tips to effective presentations

Better than average communicators are generally more successful than most people, but great communicators are the ones that start movements. They are remembered long after their speeches. Think Jefferson, Churchill, Gandhi, Kennedy, King, Mandela and Obama, to name but a few.

Failure to communicate effectively in science can means research won’t get funded, products won’t get sold, projects won’t get backing, and careers won’t thrive. As career scientists, your ability to deliver captivating talks can mean the difference between acclaim and toiling in obscurity.

So here are my six simple tips you can adopt in 2022 to move your presentations to a new level, enabling you to communicate in ways that are passionate, powerful, and inspiring.

Tip #1: Unleash the Master Within

Thomas Jefferson, the third President and Founding Father of the United States of America is highly regarded even today as one of America’s most influential leaders. He was a passionate believer in democracy and considered it essential to the expression of society. He promoted national self-determination, public education, and a free press.

As the principal author of the United States Declaration of Independence, he wrote many inspiring speeches, which went on to shape the course of history. The preamble to the Declaration of Independence, for example, evokes the original spirit of the American nation:

‘We hold these truths to be self-evident, that all men are created equal, that they are endowed, by their Creator, with certain unalienable Rights, that among these are Life, Liberty, and the pursuit of Happiness….’

Passion and public speaking are intimately linked. To touch your audience, you need to dig deep to identify how you’re uniquely and meaningfully connected to your presentation topic. This is where you’re operating at people’s emotional level. Passion is your why, or inspiration. It is not a passing interest or a hobby but rather that thing that’s core to what makes you, you! It is what gives you the authority, mastery and command, and your presentation will be empty without it.

Bear in mind that in some situations, what fires you up might not be obvious. Often, it is dressed up as something else. Howard Schultz, the former Chairman and Executive of Starbucks once said his passion was not coffee, but rather creating a third place between work and home! Coffee was only the by-product.

Passion is what makes successful speakers always enthusiastic about sharing their ideas. They have bags of charisma. They radiate joy and positivity about their ideas, and they are motivated by ‘good’ intentions, such as a desire to make a difference, create impact or leave a legacy.

Just as we know that happiness at and passion about the work are vital to career success, it is the same with public speaking. If you’re not having a great time in your job, how do you expect to generate enthusiasm in your presentation about it?

So while we can talk about effective storytelling, designing beautiful PowerPoint slides or how to use body language more effectively in your public speaking but the fact, and it is a fundamental fact, that effective presentations require passion first. Effective stories, slides or body language mean little if the speaker does not radiate passion and enthusiasm about what they’re communicating.

Tip #2: Master the Art of Storytelling

In this information-saturated age that we live, you won’t be won’t be heard unless you tell compelling stories. Facts and figures, and all the rational things that we think are important in science actually don’t stick in our minds that well. However, stories create “sticky” memories by attaching emotions to things that happen.

Stories also affirm who we are. We all want affirmations that our lives have meaning. And nothing does a greater affirmation than when we connect through stories.

This is why people who know how to weave stories about their work and share good stories have a powerful advantage over others.

But what constitutes a good story? Consider the case of major film studios, such as MGM, Pixar and Disney. They have individually mastered the ability to move audiences deeply, causing adults to tear up next to children, while persuasively transporting us into make-believe worlds.

Their perennial success in the business of movies is down to the way they choose ideas, create compelling characters, invoke empathy, drama and conflict, create villains and heroes, and the endings (the moral), that is, storytelling. It is the same with great speakers.

Aristotle, the Greek philosopher, believed that persuasion happened when three components were represented: ethos, logos, and pathos. Ethos is credibility. We tend to trust and agree with people we respect for their achievements, titles, experiences, etc. Logos is about persuasion through logic and data. Pathos is the act of appealing to emotions.

You can see this approach in Stevenson’s TED talk. For instance, he started with his personal experiences. The first five minutes (30 percent of the presentation) were on his personal stories and experiences. Data about incarceration in U.S. prisons came in later to support his ideas. He chose his approach to make it easy for the audience to connect with him on a personal and emotional level.

Studies have shown that inspiring communicators use three types of story.

The first types of story are personal stories about who we are. They should be descriptive and rich with imagery to enable the listener to imagine themselves with you at the same time. Delivered well, a captivating story makes your audience know something about you, which builds trust. Granted, personal stories are a sensitive subject, but if you choose them carefully, nothing comes close to grabbing the audience’s attention early on. A personal experience that produced an unexpected outcome often works well. The key thing is not to make them show how great you are, etc.

The second types of story are stories about other people who have learned a lesson the audience can relate to. The power of such stories is that they shed light on our shared humanity. So while personal stories can evoke empathy, it is stories about other people that audiences mostly empathise with. Empathy is the capacity to recognise and feel others’ experiences.

The third type of story are stories about successes or failures of products or brands. Harvard Business School is famed for the Case Method to teaching MBA students. These cases usually tell stories (real or simulated) about challenges faced by business executives and lessons that can be learnt from their experiences. This way, students are able to relate to business theorems with particular challenges.

Just as a great novel or movie goes about storytelling, a great presentation has to have a narrative, a cast of characters (hero and villain) and the moral of the story. The story should reveal a challenge (villain) being faced, a protagonist or hero (your solution) who is committed to rising to the challenge, the townspeople (customers) to be freed by the villain, and the outcome (the people who will be freed and live happily ever after their struggles are ended).

Tip 3: Have a Conversation

Great speakers deliver their content in a natural, authentic way, akin to having a comfortable conversation with a friend. It is a skill learned through practice and is not something that can just be memorised and perfected in an instant.

Think of the times you had a genuine conversation with a friend. Hopefully, you’re typically operating in a zone of emotional rapport. You were able to persuade your friend because you had gained their trust, and your voice, gestures, and body language were all in sync with your words.

This authenticity does not happen spontaneously. It is something that is learned, through practice. It takes hours of practice, searching for the right words that best represent the way you feel, delivering those words in a powerful way for maximum impact.

Good verbal delivery is based on what is called in the military as ‘commanding presence’. Commanding encompasses the following key elements:

  • Rate: the speed at which you speak
  • Volume: the loudness or softness
  • Pitch: high or low inflections
  • Pauses: short pauses to put emphasis on key words
  • Gestures, facial expressions, and body language

Great communicators speak at the right rate (the ideal rate of speech is between 180 and 200 words per minute), they speak concisely and precisely, and their voices project across the entire room because they speak from their diaphragms. They compliment the words with the gestures and facial expressions, to make a strong argument even stronger.

Tip 4: Reveal Something New

Great speakers incorporate new information or perspectives that are completely new to their audiences. The information may be packaged differently or presented in a way to solve an old problem. Revealing new perspectives works because our human brains love novelty. Unfamiliar, unexpected or unusual outcomes in a presentation audience, jolts them out of their preconceived notions, and provides them with new perspectives.

One of the most captivating public speakers on the web today is Professor Hans Rosling. He often talks about population, economic development and global health issues. As well as delivering data in a fascinating and easy-to-digest way, he is able to reveal completely new perspectives.

This is the same approach taken by all successful communicators. They opt to deliver content in ways that reveal something that is entirely new; things the audience was not familiar with.

Seth Godin, the popular blogger and author, has made a career out of delivering ideas differently. He told a TED audience in 2003 that in a society with information overload, the natural instinct is for audiences to ignore most of it. Thus, delivering the same old, tired content using the same boring methods as everyone else is bound to fail. Adding a little spin to content allows the audience to be more receptive to the message.

Tip #5: Incorporate Jaw Dropping Moments

A jaw-dropping moment in a presentation is when the speaker delivers a shocking, impressive or surprising moment that is very moving and memorable that it grabs the audience’s attention, and is remembered long after the presentation is over. Jaw-dropping moments are capable of heightening emotions, helping listeners recall and act on the message.

In 2009, Bill Gates, the founder of Microsoft delivered a talk at a technology conference about malaria. While on stage, he opened up a glass jar and said, “Malaria is spread by mosquitoes. I brought some here, just so you could experience this. We’ll let those roam around the auditorium little bit. There’s no reason only poor people should have the experience.” The audience roared with laughter, cheered, and applauded. Bill Gates had effectively delivered his jaw-dropping moment.

A few sentences earlier, Bill gates had talked about how many children lives’ could be saved through better medicines and vaccines. He was able to deliver an emphatic talk. He used shock and humour to drive his point home.

Journalists call the mosquito gimmick “the hook.” It’s the wow moment, the showstopper and the device used to capture the audience’s attention. Used cleverly, it allows listeners to share your story. So, before creating a Power Point presentation, take time to think about the story first. In the same manner a movie director storyboards the scenes before shooting, you should create the story before opening the tool. Aim to tap into al the senses – seeing, touching, feeling, and smelling.

Things that shock, surprise, bring fear, joy or wonder impact how vividly we remember them. It is the reason many of us remember our first kiss, the birth of a child, winning an award, break-ups or death of a loved one. It is as though these emotionally charged events are burned into our memories. Therefore, if you want to connect with an audience in an emotional level, you will need to present information that is vivid, using tools and examples that meaningful and concrete.

Tip #6: Be mindful of Cognitive Backlog

Most memorable presentations are noted for three key elements:

  • Are concise and organised systematically
  • Use multisensory approaches to paint mental pictures in their audiences
  • Are authentic, open and transparent.

Conciseness and Organisation

It is an undeniable fact that listening is mentally draining. Thinking, speaking and listening are physically exhausting. Think of the last time you sat through a one-hour lecture or power Point presentation. Too much information prevents the effective transfer of ideas, leaves the audience anxious and even frustrated. Researchers refer to this information overload as “cognitive backlog,” which is akin to piling on weights, which makes the mental load heavier.

This is the reason all TED talks are required to be no more than 20 minutes. TED believes that 20 minutes is short enough to hold one’s attention, and long enough to cover anything relevant.

If you must give longer presentations, it is necessary to split them into chunks, for instance, by adding breaks, videos, stories or demonstrations, every 10 minutes. The longer the presentation, the more the listener has to work to organise, comprehend and recall information.

John F Kennedy, the 35th president of the United States, gave a famous speech at Rice University in late 1962. It was here that Kennedy outlined his vision for America to explore the moon. The speech, which lasted just over 17 minutes, captured the nation’s imagination about the importance of exploring space.

But it is not enough to be concise. In fact conciseness means nothing if the information is haphazard and unstructured. This is why some influential communications professionals talk of the rule of threes. This rule simply means that people remember three pieces of information well. Add more items and retention starts to wane quickly.

To make use of the rule of three, structure your story in three key chunks or messages around a central theme. It turns out that the rule of three pervades our work and social lives on a daily basis. You will find it in literature (the three little pigs and, the three musketeers), in the arts (three primary colours), politics (the three arms of government), etcetera. If it works for the world’s greatest writers and painters, it will work for presentations, too.

Use of Multisensory Experiences to Paint Mental Pictures

Think again about a particularly boring talk you had the misfortune of attending. What made it boring? What was your level of engagement? Chances are that it had too much text, lacked structure, was visually unappealing and the content was unengaging.

The fact is that boring does not wash well with the human brain. The brain craves multisensory experiences and will quickly switch off when it is exposed to stuff that is boring. Having presentations that include more than one sense: sight, sound, touch, and smell are difficult to ignore. This is why great talks use mesmerizing images, captivating videos, intriguing props, beautiful words, and more than one voice to bring the story to life.

Granted, some of these experiences, such as smell and taste, are difficult to incorporate in presentations. The key thing is to build a presentation around one or two main senses, and incorporate one other. The harder experiences can be simply described.

Slides should incorporate images and videos rather than text whenever possible. The audience is far more likely to recall information when it is presented in a combination of pictures and text rather than text alone.

The other important sense to use is sound. The auditory sensation is very powerful and how the content is delivered (pitch, rate, volume, intensity, sound effects) can all touch the listeners soul.

The final sensation to use is feeling. Feeling has been described as the “holy grail” of presentations owing to its ability to transport audiences to another place. The visual display of information helps the audience to see it while touching allows them to complete the journey.

Being Authentic, Open and Transparent

Although public speaking is an artform, it is not act one can put on. Am sure you have met a person who acts and speaks one way in private only to sound completely different when delivering a presentation. Such people act, look and sound like two different people. They lack authenticity, openness and transparency. Unfortunately, audiences are not thick – they can see through a fib, so trying to be somebody you’re not is a sure way to fail at building rapport with your audience.

If your goal is to inspire the audience and take them with you, you must be real. Here are some things to do:

  1. Use your own voice – there’s no need to sound ‘posh’ or adopt some ‘esoteric voice.’ Chances are that it will make it difficult for your audience to keep up.
  2. Disregard the fact this is a presentation. Instead, regard it as a conversation, the kind you typically have with family and friends.
  3. Relax! This is not a sermon on the mountain, rather you’re just sharing your knowledge and expertise for people to take as much, or as little, as they wish.
  4. Be yourself – you’re fantastic at it!

Finally, try to recapture your inner 3-year old-the times you were carefree, and had no hang ups. If you can get back to that, you’ll be an impactful public speaker.

Pharmaceutical Matrix Forming Excipients: Overview, Types, and Selection Criteria

As medical needs become more complex, the need for modified release pharmaceutical dosage forms becomes ever more salient. The matrix tablet technology, which uses matrix forming excipients, has been instrumental in this quest. But exactly what is a matrix former? How do they function, and how are they used? This technical note provides an overview, types and function of this important class of pharmaceutical ingredient.

What is a matrix forming excipient?

Matrix forming excipients are a class of materials used to fabricate sustained-release (prolonged release) pharmaceutical tablets. The matrix former creates a three-dimensional network that not only acts as a structural and functional scaffold for active ingredients but is the physical embodiment of the dosage form.

The matrix controls the entry of GI fluids into the tablet which retards the rate of diffusion of the active ingredient from the tablet, hence, its elimination half-life (time taken for the drug’s plasma concentration to reduce by 50%).

Matrix tablets have been around for more than half a century. Their benefits are easy to see when you consider the fact that 75 percent of all sustained release solid dosage forms used by patients today utilise matrix systems, a proportion that is larger than tablet film coatings, and many other approaches currently available for use to pharmaceutical scientists.

Why are matrix formers used in tablets?

The main reason for using tablet matrices is to achieve sustained release drug delivery. These dosage forms are designed to deliver active ingredients over a period of up to 24 hours. This results into longer-lasting therapeutic effects while reducing dosing frequency and side effects, while improving individual’s well-being.

The achievement of both goals improves patient adherence to medication, making treatments more successful, while also reducing costs of healthcare, especially for chronic conditions. This is increasingly important, due to changing demographics (aging), and children with medical complex needs. Click here to read about the importance of applying empathy in new drug development, and the challenges faced by patients with swallowing problems.

Matrix tablets are selected to formulate sustained release oral dosage forms because of ease and the economics of their manufacture. These products can be easily manufactured by direct compression or wet granulation depending on the type of polymer and additional excipients used in the formulation.

Generally, active drug substances best suited for incorporation into matrix systems exhibit the following characteristics:

  1. They exhibit neither very slow nor very fast rates of absorption and elimination. Drugs with slow rates of absorption or elimination half lives in excess of 10 hours are inherently self-retarding.
  2. Drug substances that have very short half-lives below 2 hours require special care during development because of potential huge fluctuations in plasms levels
  3. Drug substances whose solubility in aqueous media should be good and also maintain adequate residence time in the gastrointestinal tract.
  4. Active ingredients that are poorly absorbed or at unpredictable rates are also not good candidates for sustained release formulations.
  5. Finally, drug substances with very narrow therapeutic windows or really small doses are also poor candidates for sustained release formulations because of the difficulty of limiting control of release and preventing dose dumping.

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Types of matrix forming excipients

The different materials currently used to formulate matrix tablets can be classified into four groups on the basis of the basis of their drug retarding mechanism:

Hydrophobic matrix formers

Hydrophobic matrix materials are water-insoluble large molecular weight polymers for use in the fabrication of sustained release dosage forms. Examples of hydrophobic matrix formers include

  • Polyethylene
  • Polyvinyl chloride
  • Ethylcellulose, and
  • Acrylate copolymers

Sustained drug release is produced as a result of swelling and diffusion through a network of channels that exist between compacted polymer particles. The rate-controlling step in these formulations is speed of liquid entry into the matrix.

Lipid matrix formers

Lipid-based matrix formers are high melting point fatty acids and/or waxes capable of forming matrices for sustained release. Drug release from such matrices occurs through both pore diffusion and erosion.

Release characteristics are therefore more sensitive to digestive fluid composition than to purely insoluble polymer matrices.

Examples of lipid matrix formers include

  • Carnauba wax in combination with stearic acid,
  • Glyceryl dibehenate
  • Glyceryl tristearate
  • Tripalmitin
  • Trymyristin, and
  • Hard Fats

Lipid matrices are inert, non-eroding and non-dissolving systems that achieve drug release prolongation through the creation of a hydrophobic domains in the tablet. These domains not only slow down the hydration of the tablet but they also control the rate of dissolution and release of the drug into the aqueous milieu.

Hydrophilic matrix formers

Hydrophilic matrix formers are the most widely used materials of their kind owing to their ease of use, cost-effectiveness and wider regulatory acceptance. They are typically hydrophilic, high molecular weight polymers with high gelling capacities. Upon contact with water, they swell and gel, creating a moving barrier that regulated the rate of drug release. For this reason, they are also known as swelling controlled release systems.

Polymers used in the preparation of hydrophilic matrices are divided in to three broad groups

  1. Cellulose derivatives, such as methylcellulose, hydroxypropylcellulose, Hypromellose, and Sodium carboxymethylcellulose.
  2. Non cellulose natural or semi synthetic polymers such as Agar-Agar; Carob gum; Alginates; Xanthan gum, Pectin, Chitosan and Modified starches.
  3. Polymers of acrylic acid, such as Carbomer 934

Biodegradable matrix

The last category of matric forming materials are a special group of polymers that are biologically degraded or eroded by enzymes to generate simple metabolites that are eliminated through the usual processes. These polymers may be natural polymers such as proteins and polysaccharides, semi-synthetic polymers or fully synthetic systems, such as the well-known aliphatic poly (esters) and poly anhydrides.

Read about the key differences between Hypromellose and Polyethylene Oxide matrix forming excipients here:

Hypromellose v Polyethylene Oxide for the Formulation of Matrix Mini Tablets

Examples of drug products that use matrix former technology

Here are examples of tablets formulated as matrix systems for controlled release:


Theophylline is a methylxanthine, chemically similar to caffeine. It is one of the drugs used in the treatment of asthma and COPD due to its safety and low cost. Theophylline sustained release tablets use hydrophilic polymers such as hydroxyethylcellulose and hypromellose in combination with polyethylene glycol 6000 and cetostearyl alcohol (as a dissolution rate retardant).


Paliperidone, which is also referred to as 9-hydroxyrisperidone, is the primary active metabolite of risperidone. It is a widely prescribed antipsychotic medication today. The oral dosage forms are available as sustained release tablets using polyethylene oxide and hydroxyethylecellulose as the matrix forming excipients.


Oxycodone is a semisynthetic opioid drug substance derived from thebaine. It is similar to hydrocodone and morphine. It is currently used for moderate to severe pain due to its powerful analgesic and sedative properties. It exhibits excellent oral bioavailability and is commonly used and/or co-formulated with other analgesics. It is available as sustained release tablets, immediate release tablets, oral solutions and injectables. Matrix tablets when used as the drug release prolonging technology make use of ammoniomethacrylate copolymer (Eudragit® RS 30D), polyvinyl acetate and Glyceryl dibehenate.


Felodipine is a methyl and ethyl diester of 4-(2,3-dichlorophenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylic acid. Together with amlodipine and nifedipine, felodipine is a calcium-channel blocker that lowers blood pressure by reducing peripheral vascular resistance through a highly selective action on smooth muscle in arteriolar resistance vessels.

Felodipine sustained release tablets are variously formulated using either hydrophilic or hydrophobic matrix formers, such as Hypromellose K4M and hydrogenated castor oil.

Benefits of using matrix forming excipients

The reasons why particular matrix formers are selected for use by pharmaceutical formulation scientists are many and varied. There is no doubt, however, that as a technology class, these materials offer many advantages, which are outlined below:

  • Improve patient convenience and compliance by enabling the formulation of prolonged release dosage forms (e.g once-a-day tablets) that reduce dosing frequency
  • Highly versatile in terms of the active ingredients that can be formulated and the manufacturing methods
  • Enable the reduction of drug toxicity since the decrease plasma fluctuations and maintain drug within the therapeutic window
  • They can enhance product stability
  • Prolonged release drugs permit the use of lower amount of total active ingredients thereby reducing drug utilization and exposure
  • Improves bioavailability of some drugs
  • Matrix formers are relatively inexpensive as a technology

Summary about pharmaceutical matrix formers

Matrix tablets are widely used in the development of sustained release products. A wide range of inactive ingredients known as matrix formers, including hydrophilic, hydrophobic and biodegradable polymers, as well as high melting point lipids are used in matrix tablets. These systems are popular because they are well studied and are amenable for manufacture on standard equipment and processes.


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Investigation of Drug Degradation in Moisture Barrier Coated Non-Hygroscopic Tablets

*Bricklane Innovations

St Johns Innovation Centre

Milton, Cambridge CB4 0WS


**Department of Pharmaceutics

UCL School of Pharmacy, University of London

29-39 Brunswick Square

London WC1N 1AX


This study investigated the moisture barrier performance of polymer film coatings on a low hygroscopic tablet formulation based on dibasic calcium phosphate dihydrate and aspirin. Tablets were prepared by direct compaction and coated with aqueous dispersions of Eudragit® L30 D-55, Eudragit® EPO, Opadry® AMB and Sepifilm® LP.

Moisture uptake was studied by dynamic vapour sorption at 0 and 75% RH (25 oC). Stability was studied at 75 %RH/25 oC for 120 days and HPLC assay used to determine aspirin content.

Uncoated tablet cores equilibrated rapidly and took up very little water (0.11±0.006 %), confirming their low hygroscopicity. The amounts for coated cores varied as follows: 0.19±0.001 (Eudragit L30 D-55), 0.35±0.005 (Opadry AMB), 0.49±0.006 (Sepifilm LP) and 0.75±0.008 (Eudragit EPO) indicating that coated cores had higher uptake.

There was a progressive decrease in the strength of aspirin in all the samples studied, with the coated cores showing more pronounced degradation of the active (mean % aspirin recovered after 4 months was 80.02±0.04 for uncoated cores compared with 78.75±0.30 for cores coated with Eudragit L30 D-55, 76.15±0.55 for Opadry AMB, 75.98±1.25 for Sepifilm LP and 66.45±1.13 for Eudragit EPO).

It is concluded that the benefits of using polymer films as moisture barrier coatings to increase drug stability in tablet formulations of low hygroscopicity are limited.

1 Introduction

Many physical and chemical properties of pharmaceutical substances are modified when they take up appreciable amounts of water (Dawoodbhai and Rhodes, 1989). During pre-manufacture processing, raw materials may come into contact with water, and some moisture may be retained as a result. Finished products can also become exposed to water vapour during manufacture, for instance while in temporary storage in the warehouse before packaging or even when in use by the patient. Water sorbed this way has the potential to alter functionality of the product, including key properties like disintegration and dissolution, and chemical and physical stability (Carstensen, 1988). For many drug products, especially those with moisture-sensitive ingredients, preventing water uptake is a key objective.

There are many ways of minimizing water uptake into dosage forms and/or preventing its interaction with active drug substances susceptible to hydrolysis. One approach involves the careful selection of excipients that are able to bind or repel water. When combined with a variety of technologies and packaging solutions, the deleterious effects of environmental water can be mitigated (Zografi and Kontny, 1986; Ahlneck and Zografi, 1990; Alvarez-Lorenzo et al, 2000).

A relatively recent innovation is the application of polymer film coatings with moisture barrier properties onto actual unit solid dosage forms (Mwesigwa et al., 2005). This approach is attractive since it provides a means of limiting moisture uptake into the product in addition to the usual benefits associated with application of polymer film coatings.

An ideal moisture barrier coating should exhibit low permeability to water vapour. Additionally, the coating should have a high moisture binding capacity so that any sorbed water can be prevented from reaching into the core.

In previous studies, the moisture uptake and permeability characteristics of polymer films commonly used as moisture barrier coatings were described (Eudragit L30 D-55, Eudragit EPO, Opadry AMB and Sepifilm LP).

These studies showed that polymer films exhibited complex moisture sorption behaviour with no discernable differentiation of permeability characteristics on the basis of hygroscopicity. Crucially for moisture barriers, there was no relationship between either sorption or permeability characteristics of cast films and functionality as protective coatings after application onto hygroscopic tablet cores. Our studies found that the levels of aspirin degradation were inexplicably higher in the coated cores than the uncoated cores despite coated samples achieving a net reduction in moisture uptake.

The purpose of the current study therefore was to investigate whether the same moisture barrier polymer films applied onto a non-hygroscopic tablet core might offer better protection and ensure the stability of a hydrolysable active drug substance.

2 Materials and Methods

2.1 Materials

Poly(methacrylic acid ethyl acrylate) copolymer (Eudragit L30 D-55, Evonik, Darmstadt, Germany), poly(butyl methacrylate (2-dimethylaminoethyl) methacrylate methyl methacrylate copolymer (Eudragit EPO, Evonik), a polyvinyl alcohol (PVA) – based coating system (Opadry AMB, Colorcon, Dartford, UK); and a hypromellose-based coating system (Sepifilm LP 014, Seppic, Paris, France) were free samples from the respective vendors.

Dibasic calcium phosphate dihydrate (Emcompress, JRS Pharma, Rosenberg, Germany) was purchased from JRS Pharma. Aspirin (USP Grade), triethyl citrate, talc, titanium dioxide, poly ethylene glycol (PEG) 6000, stearic acid, magnesium stearate, sodium lauryl sulphate, and carboxy methylcellulose sodium were all purchased from Sigma Aldrich (Dorset, UK).

2.2 Methods

2.2.1 Tablet Preparation and Coating

Tablet cores were obtained by direct compression and were based on aspirin (30%), dibasic calcium phosphate dihydrate (69.5%) and stearic acid (0.5%) using an eccentric tablet press (Manesty, Merseyside, UK). The tablet target weight was 200 mg and a breaking force strength of ≥ 70N.

Tablet core coating was undertaken in a laboratory-scale fluidized bed coater (Aeromatic-Fielder AG, Switzerland) at 40 oC. The coatings vendors’ recommended guidelines were followed to achieve theoretical dry weight gains of 1.8 % (Eudragit L30 D-55), 6.4% (Eudragit EPO), 4% (Opadry AMB), and 3 % (Sepifilm LP).

All coated and uncoated samples cores were thoroughly dried in a vacuum oven (for six hours at 40 oC) and stored in closed bottles over phosphorous pentoxide dessicant pending further tests.

The aspirin activity remaining in the tablet cores after coating application was compared with that of uncoated tablets. The degradation in coated samples was found to be less than 0.1 %.

2.2.2 Equilibrium Moisture Sorption-Desorption Studies

Moisture sorption characteristics of uncoated and coated tablet cores were studied in a dynamic vapour sorption apparatus (DVS 1, Surface Measurement Systems, London, UK).

Relative humidity (RH) was programmed to expose samples at 0% RH and then automatically switch to 75 %RH. The equilibration condition for each RH stage was set at a mass change rate of 0.001 %/min between two consecutive measurements.

All experiments were performed in triplicate at 25 oC. The results of water uptake are reported as the per cent dry basis (db) versus exposure time.

2.2.3 Aspirin Stability Studies

Stability studies were undertaken at 75% RH/25 oC in sealed glass desiccators, which were placed in a thermostatted incubator (Sanyo-Gallenkamp, Loughborough, UK). The RH condition was provided by a NaCl slurry. Sampling was undertaken periodically once a month for a total period of four months.

2.2.4 HPLC Assay

A previously validated HPLC method (Fogel et al, 1984) was used (with minor modification) with to assay the retained strength of aspirin with the tablets. The HPLC conditions were an integrated HP 1050 Series HPLC system, an Agilent Zorbax Exclipse XDB–C8 4.6×150 mm column and a water-acetonitrile system (75:25) acidified with orthophosphoric acid as the mobile phase.

3 Results and Discussion

The specific equilibrium moisture uptake data at the 0-90% RH/25C cycle for uncoated and coated tablet cores are shown in Fig. 1. We elected to use this cycle to illustrate the sorption patterns otherwise the rest of the data and analysis are based on the 0-75%/25C cycles.

The data show that uncoated cores equilibrated rapidly (within 50 min) and took up very little water (0.11 ±0.006 % dry basis). When contrasted with hygroscopic cores under the same studied (reported elsewhere Mwesigwa et al, 2008) showed that the uptake at 75% RH was 2.91 ± 0.011 % and equilibration time was 500 min. This therefore demonstrates that the sorptive properties of non-hygroscopic cores used in this study were limited, confirming the non-hygroscopicity of the excipients used in the formulation.

With respect to data for coated low-hygroscopic cores, it is clear that coated cores sorbed considerably more water than the uncoated samples and also took longer to equilibrate. There were further differences in sorption patterns of the different coatings. For example, Eudragit L30 D-55 and Sepifilm LP coated cores exhibited nearly similar uptake profiles (similar rates of mass change) but the total amounts of water sorbed were different. These differences are best illustrated in Figure 2, which shows the specific equilibrium mositure uptake at each time point.

The cores coated with Opadry AMB and Eudragit EPO exhibited slower rates of uptake. However, the Eudragit EPO coated core took longer to equilibrate and also sorbed the most amount of water (0.75 ± 0.008%). These results appear to suggest that application of the barrier coatings to non-hygroscopic cores did not slow the moisture uptake kinetics and may actually have “enhanced” uptake into the core. In effect, the moisture uptake characteristics obtained are from the applied films rather than the cores, the former being the more hygroscopic component.

This contrasts with the behaviour of hygroscopic cores previously reported, where it was observed that applied films resulted in a marked reduction in the water uptake and therefore thought to have contributed less to the sorption equilibrium of the cores.

Nevertheless, it should be noted that even with this apparent “enhancement”, the equilibrium total water uptake of coated non-hygroscopic cores was still only a fraction of that observed for the hygroscopic formulation (e.g., the equilibrium uptake at 75% RH for the hygroscopic core coated with Sepifilm LP was 2.18 ± 0.001 compared with 0.49 ± 0.060 for the non-hygroscopic core coated with the same polymer).

The distribution of water between the core and the applied film is an important performance characteristic of a barrier system. To determine the availability of sorbed moisture in the applied films and the tablet cores, it is necessary to recap the equilibrium moisture sorption and permeability data obtained with free standing cast films in our earlier report (Mwesigwa et al, 2008) together with the data in Fig. 1. The data showed that at 75% RH Eudragit EPO free film was the least hygroscopic with an equilibrium moisture uptake of 1.85 ± 0.255 %. The Eudragit L30 D-55 took up 2.59 ± 0.195 % db); followed by Opadry AMB (5.18 ± 1.169) and Sepifilm LP (9.64 ± 0.252 %).

In terms of permeability, the best barrier films were Eudragit EPO and Opadry AMB (permeability coefficients at 75% RH were 0.58 x10-6 and 0.69 x10-6 cm3 (STP) cm/cm2s.cmHg, respectively). Eudragit L30 D55 and Sepifilm LP free films with permeability coefficients of 1.58×10-6 and 1.92 x10-6, respectively. The data for the equilibrium sorption (in Fig. 1) provides an interesting contrast; for instance, it can be seen that cores coated with Eudragit L30 D-55 were the least hygroscopic, followed by Opadry AMB, Sepifilm and Eudragit EPO.

This suggests that the barrier properties of the films were not being replicated on the cores. This pattern becomes more clear when the distribution of the sorbed water between the film and the core is considered.

Table 1 displays the amounts (in mg) of moisture in the applied coatings (calculated from the product of the total uptake in % of the cast film and the weight in mg of applied coating) and the total water uptake (in mg) of the coated sample (being the product of % total water uptake and the weight in mg of coated sample divided by 100), and from which the amount of water that potentially reached the core can be easily obtained (being the difference of the two quantities). It can be seen that the Eudragit EPO coated samples had the highest amount of water in the core despite the low hygroscopicity and permeability of the free film. Eudragit L30 D-55 and Opadry AMB coated samples had the least quantities of water sorbed in the cores.

The behaviour of Opadry AMB system is of interest: the free film exhibited comparable permeability to that of Eudragit EPO but had much higher hygrocopicity, on the core, this film showed lower levels of water ingress into the core, which were comparable to Eudragit L30 D-55. Therefore, as in our previous report, there appears to be no meaningful relationship that can be established between either water sorption or permeability characteristics of free films and the protective function of the coatings on non-hygroscopic tablet cores.

When a coated tablet is exposed to moisture stress, it is expected that the applied coating will either completely repel the moisture or hold a portion of the moisture and allow the excess into the underlying core depending on its permeability and the amount that the core can accommodate at the prevailing conditions. Equilibrium sorption sorption is achieved when the water activity of the sample equals that of the surroundings.

Given that the cores have lower water attracting propensity than the coatings, the sorption equilibrium is largely directed by the more hygroscopic films. Under these conditions, the cores easily reach their maximum water holding capacity and any extra sorption above this amount is taken up by the film to the point equilibration with the surrounding RH is achieved. We propose this is the reason for the observed failure of the coatings to achieve a net reduction in the total amount of water taken up over the uncoated cores. This also accounts for the observation that total sorption of low hygroscopic cores are nearly a simple sum-total of that taken up by the core and the film.

Do the above results have any bearing on stability given the relatively low water uptake in non-hygroscopic cores? Figure 3 shows the results of the stability studies of aspirin in uncoated and coated tablet cores.

Firstly, it is apparent, just like the data for hygroscopic cores, that there was a progressive decrease in the strength of aspirin upon exposure to moisture stress in all samples. By the end of study, uncoated cores exhibited the lowest levels of aspirin degradation. It is worthy emphasising at this stage that the degradation observed in the samples was solely attributed to moisture uptake post coating in the fluidised bed coater.

As it would normally be expected that samples exhibiting the highest water uptake also show the greater aspirin hydrolysis, the outcome of the stability studies does not appear paradoxical. However, when viewed in the context of the barrier characteristics of the films or the total amount of water taken in (and in comparison to the hygroscopic cores), it can be seen that despite the non-hygroscopic cores taking up only a fraction of the amount of water taken up by the hygroscopic cores, the extent of degradation was higher in these samples. Also, as no correlation between water sorption/permeability characteristics of free standing films, total water uptake of uncoated/coated cores with the extents of hydrolysis of aspirin in the cores to which the films have been applied can be established, it would suggest that the ability to prevent drug degradation in the non-hygroscopic tablet cores is not necessarily the result of preventing moisture uptake, per se.

It is already well known that excipients play an important role in the stability of moisture sensitive actives. For instance, the influence of the particle size and pore volume distribution of dibasic calcium phosphate dihydrate on the hydrolysis of aspirin has been reported (Landin et al, 1994).

Other factors, including hardness (Lee et al., 1966); excipient type and crystallinity (Maulding and Zoglio, 1969; Ahlneck and Alderborn, 1988, Du and Hoag, 2001) have been discussed. In this present study, we found that the low-hygroscopic formulation exhibited greater degradation despite the lower levels of water uptake. In this formulation, more of the sorbed moisture was available as free water, which was more available to interact with aspirin.

It is also apparent that while coated cores sorb more water than the uncoated cores, we are inclined to believe that considerably higher levels of degradation of coated non-hygroscopic cores are a result of a combination of other factors rather than water uptake alone. We have previously proposed that when coated tablets are exposed to moisture stress, the adhesion of the coating to the core is compromised and this augments the degradation of aspirin over and above the levels that would be observed through simple permeation into the core (Mwesigwa et al, 2008).

There is already a significant body of corroborating evidence to support our proposition (Okhamafe and York, 1985, Felton and McGinity, 1997). It is widely known that adhesion is of primary importance to barrier performance and its loss compromises the ability of the coating to provide mechanical protection to the substrate (Fung and Parrot, 1980, Klages et al 1996 and Barranco et al, 2004), who have reported the formation of a water layer at a paint film-substrate boundary and associated this phenomenon with a reduction in adhesion to the substrate and greater levels of corrosion in oxidation.

4 Conclusions

This study was undertaken to understand whether the stability of a moisture sensitive active could be improved through application of moisture barrier coatings on tablet cores exhibiting low hygroscopicity. The moisture barrier coatings applied to tablet cores did not achieve a net reduction in the amount of moisture sorbed when exposed to elevated RH. The uncoated cores exhibited lower overall levels of aspirin degradation compared with coated samples. The use of current moisture barrier coatings on tablet cores with minimal water uptake characteristics does not appear to prevent the degradation of moisture sensitive actives.


Ahlneck, C., Alderborn, G. 1988. Solid-state stability of acetylsalicylic-acid in binary-mixtures with microcrystalline and microfine cellulose, Acta Pharm. Suec. 25, 41–52.

Ahlneck, C., Zografi, G. 1990. The molecular basis of moisture effects on the physical and chemical stability of drugs in the solid state. Int. J. Pharm. 62, 87-95.

Alvarez-Lorenzo, C., Gomez-Amoza, L., Martinez-Pacheco, R., Sonto, C., Cocheiro, A. 2000. Interactions between hydroxypropyl celluloses and vapour/liquid water. Eur. J. Pharm. Biopharm. 50 (2000) 307-318.

Barranco, V. Carpentier, J. Grundmeier G. 2004. Correlation of morphology and barrier properties of thin microwave plasma polymer films on metal substrates. Electrochim Acta 49, 1999-2013.

Buckton, G., Darcy, P. 1996. Water mobility in amorphous lactose below and close to the glass transition temperature, Int. J. Pharm. 136, 141–146.

Carstensen, J.T., 1988. Effect of moisture on the stability of solid dosage forms. Drug Dev. Ind. Pharm. 14, 1927-1969.

Dawoodbhai, S., Rhodes, C.T., 1989. The effect of moisture on powder flow and on compaction and physical stability of tablets. Drug Dev. Ind. Pharm. 15, 1577-1600.

Du, J., Hoag, S.W. 2001. The influence of excipients on the stability of the moisture sensitive drugs aspirin and niacinamide: comparison of tablets containing lactose monohydrate with tablets containing anhydrous lactose, Pharm. Dev. Technol. 6, 59–66.

Felton, L.A., McGinity. J. W. 1997. Influence of plasticizers on the adhesive properties of an acrylic resin copolymer to hydrophilic and hydrophobic tablet compacts. Int J Pharm 154, 167-178.

Fogel, J., Epstein, P., Chen, P. 1984. Simultaneous high-performance liquid chromatography assay of acetylsalicylic acid and salicylic acid in film-coated aspirin tablets. J Chromatog A 327, 507-511.

Fung, R.M., Parrot E.L. 1980. Measurement of film-coating adhesiveness. J Pharm Sci 69, 439-441.

Klages, C.P., Dietz, A, Höing, T. Thyen, R., Webber, A, Willich, P. 1996. Deposition and properties of carbon-based amorphous protective coatings. Surf Coat Technol 80, 121-128.

Landín, M., Perezmarcos, B., Casalderrey, M., Martinez-Pacheco, R., Gomez-Amoza, J.L., Souto, C., Concheiro A., Rowe, R.C. 1994. Chemical-stability of acetylsalicylic-acid in tablets prepared with different commercial brands of dicalcium phosphate dihydrate, Int. J. Pharm. 107, 247–249.

Lee, S., De Kay, H.E. Banker, G.S. 1966. Effect of water vapour pressure on moisture sorption and stability of aspirin and ascorbic acid in tablet matrices. J. Pharm. Sci. 54, 1153-1158.

Maulding, H.V., Zoglio, M.A., 1969. Pharmaceutical heterogeneous system: IV. A kinetic approach to the stability screening of solid dosage forms containing aspirin. J. Pharm. Sci. 58, 1359–1362.

Mwesigwa, E., Basit, A.W, Buckton, G. 2008. Moisture sorption and permeability characteristics of polymer films: Implications for their use as barrier coatings for solid dosage forms containing hydrolysable drug substances, J. Pharm. Sci. 97, 4433-4445.

Mwesigwa, E., Buckton, G., Basit, A.W 2005. The hygroscopicity of moisture barrier film coatings, Drug Devt. Ind. Pharm. 10 959-968.

Okhamafe, A.O., York, P. 1985. The adhesion characteristics of some pigmented and unpigmented aqueous-based film coatings applied to aspirin tablets. J Pharm Pharmacol 37, 849-853.

Zografi, G. 1988. States of water associated with solids. Drug Dev. Ind. Pharm. 14, 1905-1919.

Zografi, G., Kontny, M.J., 1986. The interaction of water with cellulose and starch-derived pharmaceutical excipients. Pharm. Res. 3, 187-194.

Pharmaceutical Suspending Agents: Overview, Types, and Selection Criteria

Suspending agents are excipients added to disperse systems in order to maintain particulate ingredients in suspension or to prevent other forms of physical instability. In this technical note, we provide an introductory review of what suspending agents are, and outline the function they play in pharmaceutical formulations.

Definition of a Pharmaceutical Suspending Agent

Pharmaceutical suspending agents are a class of excipients added to disperse systems to ensure that any solid particles in the formulation are kept uniformly distributed within the continuous phase, thereby maintaining physical stability of the product.

Pharmaceutical dispersions include suspensions, creams and aerosols. They typically comprise dispersions of insoluble solids (drug and/or excipients) in an aqueous or non-aqueous liquid medium, known as the continuous phase.

Depending on the particle size of the disperse phase, disperse systems can be further categorised as:

  • Colloidal (the dispersed particles are in the submicron range), and
  • Coarse (dispersed particles are above colloidal size).

Note that the term ‘suspending agent’ is frequently used interchangeably with another, closely related term, ‘thickening agent’.

As we will see, while having some commonalities the two excipients groups are different. Very simply, thickeneing agents can be used as suspending agents but not all suspending agents are thickening agents.

This is best illustrated by the following commonly used OTC products:

Pepto Bismol® is an oral suspension of bismuth salicylate (active). It is formulated with aluminium magnesium silicate, methylcellulose, and gellan gum, which are the materials used to hold the active ingredient in suspension by increasing viscosity (thickeners).

Gaviscon® is an oral suspension of sodium bicarbonate, calcium carbonate, and sodium alginate. The sodium alginate functions both as a suspending excipient and active ingredient.

Calpol® is an oral suspension of paracetamol formulated with maltitol and sorbitol (syrups), microcrystalline cellulose, sodium carboxymethylcellulose, and xanthan gum, as the suspending agents. Suspension of the active is achieved through thickening of the dispersing phased.

In order to appreciate the utility of suspending agents, it’s necessary to quickly review the technical aspects of pharmaceutical disperse systems.

The process of dispersing solid particles in a liquid creates several problems, including:

  • Creaming
  • Sedimentation
  • Flocculation
  • Caking
  • Particle growth, and
  • Adhesion onto the walls of the container (in some formulations)

The above phenomenon constitute physical instabilities, and are generally dependent on three main factors:

  • Differences in density between the dispersed particles and the dispersion medium (∆ρ)
  • Particle size (radius) of the dispersed phase r
  • Viscosity of the dispersion medium (η)

The interrelationship between these three factors is given by Stokes’ law, which is shown below:


where v is the rate of particle settling (or creaming, for that matter).

According to Stokes law, instability can be reduced by reducing particle size, decreasing density differences between the two phases or increasing the viscosity of the continuous phase.

It is worth knowing that particles will still be able to move about in the dispersion, however, the rate and intensity of collisions will be minimised. Furthermore, disperse systems are highly dynamic – dispersed particles frequently contact each other as a result of the following phenomenon:

  • Brownian motion
  • Creaming
  • Sedimentation due to gravitational forces
  • Convection

Given enough time, and in the absence of any other mitigating circumstances, the dispersed particles eventually come into close contact and may coalesce, form bonds and cake, destroying the balance of the disperse system.

Whether dispersed particles reach this point of no return depends on two factors:

  • Forces of attraction or repulsion, and
  • Nature of the surface of the dispersed particle

This is where suspending agents come into play, i.e they help minimise dispersed particle flux (sedimentation, creaming or convection) or interfere with particle-particle attraction.

We can therefore define pharmaceutical suspending agents as a specific category of excipients added to disperse systems to minimise disperse phase coalescence and instability.

Pharmaceutical suspending agents can be grouped into four main categories as outlined below:

Types of Pharmaceutical Suspending Agents

A). Wetting agents

For the disperse phase to freely and distribute in the continuous phase, it needs to be wetted by the liquid. The presence of entrapped air pockets on the particle surface or if the particles are hydrophobic is a hindrance to dispersion.

Wettability can be enhanced through the reduction of the interfacial tensions, namely solid-liquid and liquid-vapour interfaces.

1. Surface active agents

Surface active agents (surfactants for short) are excipients that lower the surface tension (or interfacial tension) between two liquids or between a liquid and a solid.

Surfactants with HLB values between 7 and 9 have been shown to be suitable wetting agents in pharmaceutical disperse systems.

This is because the apolar groups of the surfactant are able to adsorb onto hydrophobic parts of formulation particle while the polar groups project into the aqueous medium, resulting in a lowering of the interfacial tension between the solid and the liquid.

2. Hydrophilic colloids

Hydrophilic colloids are high molecular polysaccharide polymers or clays. They include acacia, bentonite, tragacanth, alginates and cellulose derivatives.

Being hydrophilic, they are able to coat particles to impart hydrophilic character to the disperse phase. In addition, hydrophilic colloids may also increase viscosity of the continuous phase, reducing the rate of sedimentation of particles.

3. Solvents

Common polar pharmaceutical solvents such as glycerol, propylene glycol and polyethylene glycol and alcohol are highly water-miscible and are able to reduce the liquid-air interfacial tension.

They enable water to infiltrate deep into power agglomerates, displacing entrapped air and enabling wetting of the dispersion to take place.

B). Flocculants

A well-formulated disperse system is one that exhibits the correct degree of flocculation. Systems that are underflocculated generally tend to settle and sediment very rapidly although the compacts formed are loose and redispersion is possible.

On the other hand, overflocculation results in products that while settle slowly the sediments pack tightly such that redispersion is not possible.

By controlling the degree of flocculation, it’s possible to reach a happy medium – in which there is a degree of flocculation and also deflocculation.

This can be achieved through, not only through particle size control and viscosity-modification, but also by using flocculating agents, including electrolytes, ionic surfactants and polymer flocculating agents.

1. Electrolytes

The addition of inorganic electrolytes to the solution changes the zeta potential of the dispersed particles, and provided this is lowered sufficiently enough, will produce a flocculated system.

2. Surfactants

Ionic surfactants can also be used to create flocculation in a disperse system by neutralising particle charges and creating a deflocculated system.

3. Polymeric flocculants

Several polymeric excipients are capable of forming gel-like networks in disperse systems thereby adsorbing onto and trapping dispersed particles and holding them in a flocculated state.

These materials are mainly hydrocolloids although not always, and include:

C). Viscosity modifiers

The deal disperse system is one that displays pseudoplastic or thixotropy behaviour, that is, exhibit high apparent viscosity at low shear rates.

Upon storage, the dispersed particles either settle slowly or, and preferably, remain suspended. When the product is sheared, for instance, when shaken by the consumer, the high apparent viscosity of the formulation should fall sufficiently for product to be dispensed easily.

The various materials currently used as viscosity modifiers are outlined below:

1. Polysaccharides

Examples of polysaccharide-based viscosity modifying excipients include the following:

2. Water-soluble cellulose ethers

Several cellulose ethers have the ability to increase viscosity of aqueous systems in which they are dispersed. They include:

The viscosity-increasing properties of cellulose ethers depends on the molecular weight and degree of substitution.

3. Hydrated silicates

Hydrated silicates are naturally-occurring siliceous clays that exist as colloids in water. This group of pharmaceutical grade clays includes:

  • Bentonite
  • Hectorite
  • Magnesium aluminium silicate (VEEGUM®)

Hydrated silicate materials exhibit thixotropic behaviour at low concentration in water and as gels at high concentration.

4. Carbomers

Carbomers are high molecular weight cross-linked polyacrylic acid polymers that swell in water to form viscous hydrogels depending on the degree of cross-linking.

Among carbomer excipients, carbomer 940 is the most commonly used suspending excipient in both topical and oral products.

If you would like to learn more about carbomers, here is a link to an article that gives an overview on these important excipients:

D). Density modifiers

From probing Stokes’ law above, it is clear that if the densities dispersed and dispersing medium are of the same magnitude sedimentation would be significantly slowed down.

Thus, changing the density of the dispersing medium, for example, addition of glycerol, propylene glycol, polyethylene glycol or sucrose-based syrups, can significantly modify densities and leveraged to control instability.

You read more about viscosity modifying excipients through this link:

Summary of Pharmaceutical Suspending Agents

Many pharmaceutical products are formulated as disperse systems in which particulate solids (active ingredients and/or excipients) are distributed throughout a continuous or disperse phase. Owing to the tendency towards settling or creaming by the disperse phase, the use of suspending agents is mandated.

There are many different types of pharmaceutical suspending agents; they can be grouped into four main classes depending on the mechanism of function:

Careful selection of suspending agents is essential in order to have a product that ensures the disperse phase does not settle rapidly, the particle do not settle into a cake, the system is easily re-dispersed into a uniform mixture when shaken, is easy to dispense from the container or use by the consumer.

Sources and Further Reading

Pharmaceutical Thickeners (Viscosity-Increasing Agents): Overview, Types, and Functions

Thickening agents are usually high molecular weight polymer excipients commonly used to increase viscosity of formulations. This can serve several objectives, including stability, ease of use and drug delivery. In this post, we provide an overview of materials frequently used to thicken pharmaceutical products.

Definition of Pharmaceutical Thickeners

Pharmaceutical thickening agents (thickeners, for short) are a diverse group of excipient materials used to increase the viscosity of liquid pharmaceutical systems, ideally without altering other fundamental properties.

They are also commonly known as viscosity-increasing agents.

Viscosity is the internal friction that occurs between the molecules within a liquid. It is a measure of the resistance to deformation in shear, such as flow or pouring, and is due to intermolecular friction and molecular adhesion-cohesion within the fluid.

Viscosity of a fluid decreases with increase in temperature due to increased atomic/molecular mobility, which decreases intermolecular cohesion and friction. The presence in solution of a high concentration of solutes can have an appreciable impact on viscosity of the solution.

This is why the terms “thick” (concentrated and high viscosity) and thin (dilute and low viscosity) are used as qualitative descriptions of the viscosity of liquid systems.

Many thickeners form weakly cohesive colloidal structures, which can exist as solutions, suspensions or gels when dissolved or dispersed in a suitable liquid medium.

Note that thickening agents are sometimes (and mistakenly) referred to as suspending agents. Although there is overlap in the type of excipients used for both product categories, there are sufficient differences to warrant a clear separation of the two categories, an approach we have taken in this article.

How Thickeners Increase Solution Viscosity

With respect to the use of polymers, the addition of a high molecular weight polymer increases viscosity of the liquid in which it is dissolved. The increase in viscosity is caused by strong internal friction between the randomly coiled and/or swollen macromolecules, and the surrounding solvent molecules, through hydrogen bonding¹. This is illustrated below:

How Thickeners Increase Solution Viscosity

With respect to the use of polymers, the addition of a high molecular weight polymer increases viscosity of the liquid in which it is dissolved. The increase in viscosity is caused by strong internal friction between the randomly coiled and/or swollen macromolecules, and the surrounding solvent molecules, through hydrogen bonding¹. This is illustrated below:

Functions of Pharmaceutical Thickeners

Viscosity is one of the most important properties associated with liquid systems, and formulations that possess high viscosity have many practical applications within the pharmaceutical space, as outlined below:

Drug delivery

The rate of drug delivery is influenced by viscosity of the milieu. Liquid and semisolid topical and oral formulations, as well as parenteral and matrix-based solid dosage forms frequently utilise high viscosity systems to slow down rates of drug diffusion.

Demulcent properties (soothing, irritation reduction & increase in slip)

Demulcents are a class of materials used to lubricate and protect mucous membranes, and more especially the oral, pharyngeal, oesophageal, and gastric mucosa. Their action depends on having sufficient tack and slip, both of which are obtained when polymeric excipients are dissolved in aqueous media. Click here to read about the challenges of dysphagia and oral medicines, and what action is required if we are to address it.

Substantivity and film formation

The ability of a formulation to adhere and remain in place (contact time) is a function of, among other factors, viscosity and film formation. Viscosity-increasing agents are routinely used to increase substantivity and contact time of topical and bioadhesive formulations.

Suspending and stability enhancement

Thickeners are typically used to minimise separation and settling that typically follow when insoluble ingredients are suspended in liquids

Improvement of appearance, consistency and quality

Thickening agents are added to skincare formulations to give skincare products a more appealing consistency and smoothness. Consistency is a particular formulation characteristic that describes the firmness or runniness of a product.

Gelling and texturizing

A key property of hydrocolloids (such as pectin and xanthan gum) is their ability to form gels and thicken liquid product. For instance, pectin, carrageenan and agar form gels under specific conditions, which opens up a myriad of applications and functionalities.

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Types of Pharmaceutical Thickening Agents

A wide range of excipients can be used as thickening agents, with the most common being hydrocolloid gums and cellulose ethers.

Hydrocolloid Gums

The term ‘hydrocolloid’ is derived from two Greek words, ‘hydro = water, and ‘kolla’ = glue. Currently, the term hydrocolloid is used for macromolecular (polymers) hydrophilic substances (with affinity for water), and includes polysaccharides and proteins.

When dissolved or dispersed in water, hydrocolloids hydrate and swell (increase in volume) due to solvent molecules penetrating into void spaces that exist between polymer chains. Hydration is accompanied by an increase in viscosity.

Hydrocolloids can be classified into four groups:

Plant-derived hydrocolloids: including pectin, agar, Alginates, acacia, tragacanth, Karaya gum, guar gum, starches, cellulose and locust bean.

Products of fermentation: including xanthan gum, dextran, gellan gum and pullulan.

Semi-synthetic hydrocolloids: including modified starches, cellulose ethers (Methylcellulose, Hypromellose, Ethylcellulose, Hydroxypropylcellulose and hydroxyethylcellulose), amidated pectin and propylene glycol alginate.

Animal derived hydrocolloids: such as gelatin, chitosan and caseinates.

Vinyl polymers

Vinyl polymers is a generic term given to high molecular weight synthetic polymers based on the vinyl groups: XCH=CHY. In the pharmaceutical field, the most important vinyl polymers are:

Water soluble polyvinylpyrrolidones: This group includes povidone and copovidone of molecular weights ranging from 2500 to 1250000 g/mol.

Ethylene-vinyl acetates: Ethylene vinyl acetates (EVAs) are copolymers of ethylene and vinyl acetate monomers produced by free radical polymerisation under high temperature and pressure.

Varying vinyl acetate composition impacts polymer properties such as melting point, crystallinity and polarity, solubility, transparency, hardness and compatibility with active ingredients.

EVAs are mainly applied in the formulation of transdermal drug devices and Class I – IV medical devices, where they are used as and/or incorporated into matrix formers, rate controlling membranes and backing layers. EVAs provide tackiness, bioadhesion and flexibility.

Polyvinyl alcohol: Polyvinyl alcohol (PVA) is a water-soluble and biodegradable polymer obtained by polymerisation of vinyl acetate followed by partial hydrolysis. Pharmaceutical grades typically exhibit a degree of hydrolysis of 88% and molecular weight that vary from 20 000 g/ml to over 100 000 g/mol.

Clays (Aluminium Silicates)

Clays are fine-grained naturally-occurring aluminium silicates with traces of other inorganic oxides. They typically consist of plate-like crystal habits. The most well-known clays in the pharmaceutical field are bentonite, hectorite and magnesium aluminium silicate.

Owing to their platy habits, aluminium silicate particle planes possess different surface charge characteristics and complex modes of particle-particle interaction, depending on concentration and pH, among other factors.

In suspension, hydrodynamic forces or the influence of electroviscous effects of clay solutions impacts rheology and viscosity of clay suspensions, much the same way as polymers dispersions.


Carbomer are a group of closely related synthetic, high molecular weight, nonlinear polymers of polyacrylic acids, cross-linked with a polyalkenyl polyether. They differ in molecular weight, polymerization solvent or side-groups and contain between 56 and 68% w/w carboxylic acid groups.

Carbomer are highly versatile and multifunctional excipients for oral (solid and liquids) and topical formulations. When hydrated and neutralised, they yield highly viscous gels with viscosities upwards of 40,000 mPa s for concentrations as low as 0.5% w/v.

If you’re interested in learning more about carbomers, we have prepared a quick reference guide which you access through this link:

Carbomers: Overview, key properties and formulating tips

Polyols, sugar and oligosaccharide

Concentrated solutions of sugars, oligosaccharides and polyols behave very much like high molecular weight polymer solutions owing to increased intermolecular attractions between sugar molecules (hydrogen bonds) and the solvent. When sheared, the interactions create a drag which manifests as an increase in viscosity.

This class of viscosity-increasing agents include liquid Sorbitol, liquid Maltitol, sucrose, fructose, dextrose, maltodextrin and Polydextrose.

Miscellaneous Thickening Agents

Polyethylene glycol and polyethylene oxide: Polyethylene glycol and polyethylene oxide are related non-ionic polymers formed by the reaction of ethylene oxide and water under pressure in the presence of a catalyst. Low molecular weight polyethylene glycol grades are liquids and used primarily as solvents and co-solvents in oral and topical formulations. Solid polyethylene glycol grades are used suspending agents or to adjust the viscosity and consistency of other suspending vehicles.

Silica: Also known as colloidal silicon dioxide, silica is an oxide of silicon with the chemical formula SiO2. Silica grades with a high specific surface area are used to thicken polar liquids thereby converting them into transparent gels. This effect can be used as stabilising strategy for emulsions and semisolid preparations.

Other materials which can be used for thickening formulations include:

Summary of Thickening Agents

Many pharmaceutical excipients are often added to formulations to increase the viscosity or thicken liquid formulations. This property can be utilised to improve product properties, including drug delivery, stabilisation, demulcent effects, and texturizing. The range of materials that serve this function is very broad, but typically includes hydrocolloid gums, synthetic polymers, sugars and polyol syrups and many other miscellaneous materials.

Pharmaceutical Diluents and Fillers: Overview, Types, and Uses

Diluents and fillers are a ubiquitous class of materials in formulated products, including pharmaceuticals, medical devices, vaccines, nutraceuticals, cosmetics and industrial goods. But what exactly are diluents and fillers? Do they perform any function beyond filling up space? This technical note provides an introductory review of pharmaceutical diluents and fillers. The information will be particularly relevant to anyone interested in learning more about fillers and diluents.

Definition of Pharmaceutical Diluents and Fillers

For the vast majority of medical products in current use, the active pharmaceutical ingredient is rarely administered in its basic form. Often, this is because it is present in much lower amounts relative to the weight of the dosage form unit.

A specific type of excipients known as bulking agents are therefore added to product formulations to provide bulk and render the product convenient to process, manufacture or administer.

Alternative names for fillers and diluents are:

  • carriers
  • fillers
  • diluents
  • extenders
  • voluminising agents

Not every formulation requires a diluent – in product formulations where the active ingredient or other functional excipients are already added in sufficient proportions, for instance, greater than 70 – 90% a bulking agent may not be required.

When added, however, and despite their humble name, pharmaceutical fillers do a lot more than just fill space. Here are some of their functions:

  • add structure
  • aid application e.g., mouthfeel
  • impact appearance
  • influence many quantifiable properties that are important to a product’s performance.

In solid dosage forms, fillers and diluents are almost always required as they provide the foundation upon which the formulation is constructed.

For convenience of administration (holding and swallowing, for instance), a tablet should weigh no less 50mg, and where the active ingredient is present in very low quantities, a diluent with high carrying capacity is absolutely essential. This is an important consideration, particularly today given the increasingly high percentage (and growing) demographic of seniors across the world. Click here to read about the importance of applying empathy in new drug development.

As shown in the graphic below, diluents are often present in the highest concentration.

Diluents and fillers are not limited solid dosage forms only – their usage also applies to many other product types, including topical creams and lotions, parenteral products, dusting powders, aerosols, suppositories, and suspensions.

Types of Pharmaceutical Diluents and Fillers

Pharmaceutical fillers are very diverse group of excipients. They may be:

  • organic chemicals
  • mineral substances
  • metal oxides
  • polymers
  • simple inorganic chemicals,
  • liquids,
  • gases (aerosols)

They may be classified on the basis of

  • source (natural, mineral or synthetic)
  • dosage form in which they are used
  • physical and chemical properties and
  • functionality

A more practical approach is to classify fillers as either functional or non-functional.

Functional fillers are those excipients that extend the property gamut of the formulation, opening up new performance qualities and functionalities. For example, silica is frequently added to elastomers and rubbers to provide to the topical medical device strength and structure without compromising drug delivery properties.

Non-functional fillers, as the name suggests, only serve one thing – to provide bulk and fill void volume in the formulation, which is still an important requirement in the formulation for the reasons outlined previously.

The image galery below shows fillers that may be encountered in the pharmaceutical industry:

  • maltodextrin (used as a carrier for a pharmaceutical flavour)
  • native maize starch
  • compressed chewing gum base

Ideal Properties of a Pharmaceutical Filler and Diluent

When it comes to pharmaceutical formulations, there are a number of fundamentals properties that formulators seek in fillers:

  • Physiological inertness
  • Filler concentration
  • Particle size and size distribution of the filler
  • Shape and aspect ratio
  • Bulk density/carrying capacity
  • Low API binding capacity
  • Processability
  • Physical and chemical stability
  • Strength (low impact)
  • Cost-effectiveness

For solid dosage forms (tablets and capsules), the following factors (in no particular order) are the most important considerations when selecting a material to use:

  • Compressibility and compactibility
  • Flowability
  • Particle size and distribution
  • Moisture content and type of interactions
  • Bulk density
  • Compatibility
  • Solubility and effect on bioavailability
  • Abrasiveness (lubricity)
  • Stability
  • Physiological inertness
  • Cost and availability
  • Regulatory acceptance

The 10 Most Popular Filler-Diluents in Solid Dosage Forms

The following fillers are consistently the most commonly used materials in solid dosage forms:


Lactose is a natural disaccharide obtained from milk. It consists of one galactose and one glucose moiety. It is listed in the USP-NF, JP and PhEur and is also GRAS listed and included in the FDA Inactive Ingredients Database (IM, and SC: powder for injections; oral: capsules and tablets: inhalation preparations; vaginal preparations).

Lactose is one of the most widely used filler and diluent in tablets and capsules, and to a more limited extent in lyophilized products and infant formulas. Lactose is also used as a diluent in dry-powder inhalation.

Find more about lactose through these links on our site:

Microcrystalline cellulose

Microcrystalline cellulose is purified, partially depolymerized cellulose and one of the most widely used ingredients in the pharmaceutical industry. It is used in many types of dosage forms, including as filler, binder, flow aid, lubricant, texturiser, among others.

Microcrystalline cellulose is listed in all major pharmacopoeia, including the USP-NF, Ph.Eur, BP, JP and IP. It is also GRAS listed and accepted for use as a food additive in Europe and the United States and included in the FDA Inactive Ingredients Database (oral: powders, suspensions, syrups and tablets; topical & vaginal products).

Find more about the uses of microcrystalline cellulose through these links on our site:


Starch is a polysaccharide consisting of two polymers: a linear polymer known as amylose and a branched polymer known as amylopectin. Both polymers are made up of glucose residues.

Pharmacopoeia have individual monographs for different starch derivatives, including native starch, pregelatinised starch, tapioca starch, pea starch and rice starch. Starch is also co-processed with lactose and microcrystalline cellulose.

Generally, as a material, starch is a highly versatile material, finding application in many different dosage forms. It is widely used as filler and diluents in solid dosage forms. It is also added to dusting powder and also in topical products and film coatings.

Find more about the uses of starch through these links:

Calcium phosphate

Calcium phosphate is actually a family of chemical substances made up of calcium ions and phosphate anions. These include anhydrous dibasic calcium phosphate, hydrated dibasic calcium phosphate, and tribasic calcium phosphate. All the three grades are listed in the main pharmacopoeia, are GRAS listed and included in the FDA Inactive Ingredients Database.

The main advantages of calcium phosphates as filler-diluents include:

  • Chemical inertness
  • Low hygroscopicity
  • High density
  • Source of calcium
  • Natural source

Find out more about uses of calcium phosphates through the following links:

Calcium carbonate

Calcium carbonate is the calcium salt of carbonic acid. It is listed in all the major pharmacopoeia and is GRAS listed. The FDA Inactive Ingredients Database lists calcium carbonate as an excipient for chewing gum, capsules and tablets.

It is one of the main fillers used in compressed tablets. Other uses are as a bulking agent in tablet sugar-coating processes and as an extender and opacifier in tablet film-coatings.


Sucrose is a naturally-occurring disaccharide made up of a glucose molecule joined to a fructose molecule. Pharmaceutical grade sucrose is currently obtained from sugar cane and sugar beet, and is listed in all the major pharmacopoeia and the FDA Inactive Ingredients Database (parenterals, tablets, capsules, syrups and topical products). It is a highly compressible filler in tablets and selected for its sweetness, low reactivity, safety profile and cost-effectiveness.


Maltodextrin is a saccharide consisting of mixture of polymers of D-glucose units. It is prepared by the partial hydrolysis of a starch. It is a non-sweet, odourless, white powder or granules.

Maltodextrin is used as a coating agent, tablet and capsule diluent, tablet binder and viscosity- increasing agent. Maltodextrin is also widely used in confectionery and food products, as well as personal care applications.


Mannitol (D-mannitol) is a polyol and an isomer of sorbitol. It occurs as a white, crystalline powder, or free-flowing granules, with a sweet taste. It is noted for its cooling, sweet sensation in the mouth. It is official in multiple pharmacopoeia as a filler diluent as well as a therapeutic agent.

Mannitol is used as a diluent (10 – 90% w/w) in tablet formulations. It’s specific advantage is its low hygroscopicity and high compressibility. However, it is a costly filler compared with lactose and selected for use where mouthfeel is important, for example, chewable tablets.


Sorbitol is a polyol and an isomer of mannitol. It is supplied as a white or almost colourless, crystalline, hygroscopic powder. It is available in a wide range of grades and polymorphic forms, such as granules, powders and pellets for use in solid and liquid oral and topical products.

Sorbitol is used as a diluent in tablet formulations prepared by either wet granulation or direct compression. It is especially useful in chewable tablets owing to its pleasant, sweet taste and cooling sensation.

Sodium Chloride

Sodium chloride is an inorganic chloride salt having sodium as the exchangeable ion. It is listed in all the major pharmacopoeia, is GRAS and included in the FDA Inactive Ingredients Database (injections, inhalations, nasal, ophthalmic, oral, otic, rectal and topical products). It occurs as a white, crystalline powder with a saline taste.

Sodium chloride is used widely in parenteral products to produce isotonic solutions. In oral products, it functions as a diluent (capsules and direct compression tablets), and a porosity modifier in controlled-release coatings.

MaterialReason for PopularityUsage
Lactose (all grades)Highly compactibleUp to 60% w/w in tablets & capsules
Microcrystalline celluloseVersatile, inert and low costOptimum level is 15-20% w/w in tablets & capsules
Starch (all grades)Versatile, inert and low costUp to 40% w/w as a filler in tablets & capsules
Calcium phosphatesLow moisture content. Source of CalciumUp to 60% w/w in tablets & capsules
SucroseHighly compactible & Sweet tastingHighly compressible grades up to 90% w/w in tablets, capsules & oral liquids
MaltodextrinHighly compactibleUp to 50% w/w/ in tablets & capsules
MannitolMouthfeel & highly compactible and inertUp to 60% w/w in tablets & capsules
SorbitolMouthfeel & highly compactible and inertUp to 60% w/w in tablets, capsules & oral liquids

Summary about pharmaceutical Fillers and Diluents

Despite their ordinary name, pharmaceutical fillers do much more than simply fill up space. They provide structure, influence appearance, and impact many other measurable properties that ultimately determine product’s end uses.

For solid dosage forms, lactose and microcrystalline cellulose are the most commonly used diluents. Mannitol is used as a substitute for lactose, however it is costly and its use is only justified when other functional properties are sought in a formulation.

Sources Used

Pharmacentral has a strict referencing policy and only uses peer-reviewed studies and reputable academic sources. We avoid use of personal anecdotes and opinions to ensure the content we present is accurate and reliable.

  • A. Crouter, L. Briens, The effect of moisture on the flowability of pharmaceutical excipients, AAPS PharmSciTech, 15 (2014) 65-74. Pubmed
  • A. Lura, G. Tardy, P. Kleinebudde, J. Breitkreutz, Tableting of mini-tablets in comparison with conventionally sized tablets: A comparison of tableting properties and tablet dimensions, International journal of pharmaceutics: X, 2 (2020) 100061. Pubmed
  • N.O. Sierra-Vega, K.M. Karry, R.J. Romañach, R. Méndez, Monitoring of high-load dose formulations based on co-processed and non co-processed excipients, Int J Pharm, 606 (2021) 120910. Pubmed

What is an Active Pharmaceutical Ingredient?

Therapeutics, in its broadest definition, is the use of interventions aimed at alleviating the effects of disease in humans or animals.

The constitutive substances that elicit therapeutic effects are known by different names, including active, active pharmaceutical ingredient, active principle, drug substance, medicinal agents or therapeutic substance.

This article provides a comprehensive definition of active pharmaceutical ingredients and as well as answers to common FAQs.

Definition of Active Pharmaceutical Ingredients

An active pharmaceutical ingredient (or API) is defined as the chemical, biological mineral or any other entity or component responsible for the therapeutic (pharmacological, physiological, physical, etc) effects in a product, such as:

  • vaccine
  • pharmaceutical (medicine)
  • medical device

Active pharmaceutical ingredients are distinguishable from inactive pharmaceutical ingredients, commonly known as excipients or formulation aids. For a comparative discussion of what APIs are, click through this link for the World Health Organisation’s definition.

The European Medicines Agency, the US FDA and the International Conference on Harmonisation (Q7) all adopt the same definition of API as “any substance or mixture of substances intended to be used in the manufacture of drug (medicinal) products, and that, when used in the production of drug, becomes an active ingredient of the drug product.”

Many other terms are used interchangebly with active pharmaceutical ingredient. They include:

  • active
  • bulk pharmaceutical chemical
  • drug substance
  • active principle (especially for natural extracts)
  • therapeutic ingredient

You may want to take note that health authorities add qualifiers to the definition of actives, namely, that a substance becomes an active ingredient in the drug product when it’s used in the production of the drug product, and, actives are intended to provide pharmacological activity or any other direct effect that is important in the diagnosis, cure, prevention, treatment or prevention of a disease condition, or to modify the structure or function of the body.

The reason is that there are many substances that are used beyond therapeutics. For instance:

  • Insulin is also used in fermentation bioprocesses as well as an important medicine in diabetes
  • Warfarin is an aid in pest control (culling agent of Vampire bats) as well as an anticoagulant
  • Many other materials function as therapeutic substances as well as excipients. This list include simethicone which may be used as a processing aid or therapeutically as an anti-flatulent; docusate sodium is both an medicinal active (laxative) and a excipient (surfactant), and mannitol is used both as a filler in tablets and as a therapeutic substance in the treatment of glaucoma and kidney conditions.

Consider the fact that materials intended for use as pharmaceutical actives are subjected to very strict controls, with respect to quality controls during manufacturing, distribution and use, adding a qualifier to the definition allows regulators to apply the required standards to the relevant use category (API vs processing aid vs excipient), thus preventing dilution of standards.

A key attributes of active pharmaceutical ingredients is their ability to bind to receptors and elicit a physiological response that can also be advantageously used in the treatment of disease.

The image below is an illustration of a Tyrosine kinase receptor (TRK):

TRKs represent a widely studied class membrane receptors. They participate in many cellular functions, such as differentiation and apoptosis.

This has made them of particular interest in the search for anticancer agents, with more than 20 chemical agents successfully developed into therapeutic substances.

One of these is the active pharmaceutical ingredient, Imatinib, which is marketed as GLIVEC.

To find out more about how active pharmaceutical ingredients differ from excipients click on this link: Excipients Explained: Definition, Types, Uses, and Regulatory Controls.

What are the common sources of active pharmaceutical ingredients?

On the basis of origin, active pharmaceutical ingredients can be divided into four main categories as follows:

1. Synthetic organic chemistry as a source of drug substances

This group mainly includes small chemical substances, typically with a molecular weight of under 500 Daltons. The largest category of drug substances in use today are synthetic organic substances.

Examples of APIs obtained via synthetic organic chemistry include paracetamol (Panadol® – Glaxo) and artovastatin (Liptor® – Pfizer).

With better technology, it is also now possible to synthesise peptides having up to 20 amino acid residues in the laboratory for use as drug substances. Synthetic peptides include Somatostatin, Calcitonin (Fortical – )and Vasopressin (VASOSTRICT – Parpharm)

2. Natural organic molecules as sources of drug substances

From the time immemorial, humans have resorted to the nature as a source of therapeutic substances. This remains the case today.

For example, many antibiotics such as erythromycin and anticancer agents like paclitaxel (ABRAXANE® – BMS) are isolated from nature.

3. Recombinant DNA technology as a source of drug substances

Simply put, recombinant DNA technology is the process of altering gene of an organism and using the change to produce a biological molecule such as a large protein or chemical compound.

In just over a period of 40 years, recombinant DNA technology has grown to become one of the main sources of new drug substances today. Many important actives such as Human Insulin, Human Albumin, Erythropoietin and Human Growth Hormone are obtained this way, as are many vaccines and monoclonal antibodies.

4. Whole or Extractions from natural sources (animals)

There are still many therapeutic substances that can only be obtained from natural sources either as whole organisms or extracts from organisms.

Examples of these include blood and plasma, attenuated or live viruses used in vaccines and human immunoglobulins. The same applies to cells, tissues and organs used various in biotechnology modalities.

The table below summarises the main types of active pharmaceutical ingredients arranged by their source or origin:

Active TypeSourceExamples
Conventional small-molecule drugsSynthetic organic chemistryParacetamol, Ibuprofen, Imatinib
Conventional small-molecule drugsNatural productsPaclitaxel, Aminoglycoside antibiotics, Opiates & Ciclosporin
Conventional small-molecule drugsSemisynthetic compounds (derived from nature and modified in the laboratory)Penicillins (Ampicillin) & Simvastatin
Peptides & proteinsSyntheticVasopressin & Somatostatin
Peptides & proteinsExtracted from natural sources (human, animal or microbial)Insulin, Growth hormone & Human у-globulin
Peptides & proteinsRecombinant DNA technologyInsulin, Erythropoeitin, TNF-alpha
AntibodiesAnimal antisera & human immunoglobulinsSnake & Spider venoms & HNIG
AntibodiesMonoclonal antibodiesRituximab, Trastuzumab, etc
EnzymesRecombinant DNA technologyDornase, Galactosidase
VaccinesWhole organisms (live or attenuated)Smallpox, TB, tetanus, etc vaccines
VaccinesAntigen-based vaccines produced by recombinant DNA technologySeveral
DNA & mRNA productsRecombinant DNA technologyPatisiran
CellsHuman donor and engineered cellsVarious stem cell therapies
TissuesHuman & animal donors & engineered tissuesVarious
OrgansHuman donorsTransplant surgery

Irrespective of the type of drug substance, the process of isolating, preparing and purifying active ingredients is highly involved, and requires several painstaking steps.

In situation of high demand, this step-wise approach may not suit market requirements, for example, where the therapeutic good is in very high demand (Covid 19 vaccines?).

In recent decades, the pharmaceutical industry has sought to introduce technology aimed at improving synthetic yields of actives. When successfully applied, these technologies often result in major improvements in output over traditional processes.

Some technologies, though, promise much and deliver little. Click here to read about some of the technologies that promised much but have so far failed to improve drug discovery and development.

How are active pharmaceutical ingredients regulated?

EU legislation

The standards, requirements, and procedures that active pharmaceutical ingredients must meet before they can be used in marketing authorisations are primarily laid down in Directive 2001/83/EC, Regulation (EC) No 726/2004 and Directive 2011/62/EU. These regulations also set rules for the manufacture, distribution, and sale or advertising of medicinal products.

United States

In the United States, drug substances are controlled under the Federal Food, Drug, and Cosmetic Act of 1938 and subsequent amending statutes (which are all codified into Title 21 Chapter 9 of the United States Code). This law sets quality standards for drugs and medical devices manufactured and sold in the United States and provides for federal oversight and enforcement of these standards.

Did you know?

Did you know that the first synthetic active pharmaceutical ingredient is Chloral hydrate? It was synthesized by Justin Liebig in 1832 and introduced into medicine in 1869 as a sedative hypnotic. Although its use has declined, Chloral hydrate remains in use in some countries, particularly as a sedative for children.

Further Reading

Drug Discovery and Development: A Step by Step Guide

Drug discovery and development can be described as the sum total of steps taken by research-intensive entity to identify a new chemical or biological substance and transform it into a product approved for use by patients.

This highly knowledge and capital intensive process takes, on average, 10-15 years and over $2 billion (2021 figures), to pull off.

But exactly what is involved? Who does what and when? In this article, we outline key concepts of drug discovery and development, including target identification, clinical trials, pharmaceutical development and commercialisation.

Drug Development

Drug development covers all the activities undertaken to transform the compound obtained during drug discovery into a product that is approved for launch into the market by regulatory agencies. This is a pivotal process, and a lot rides on its success, thus, efficiency is absolutely critical, but mainly for two key points:

Firstly, development is expensive – accounting for 70% of the total R&D costs. Even though the number of projects is much smaller compared with those under discovery, the cost per project is significant, and increases exponentially as the project progresses through into the latter stages.

Secondly, speed is the essence in drug development as it determines how soon the company can start earning a return on the huge investment ploughed into the project. Besides, any delays eat away into exclusivity arrangements granted by patents and time before generic manufacturers can launch me-too products.

For clarity, drug development is presented as an operation that’s distinct from discovery. In reality, the distinction is not as clear cut. Often, different activities are being undertaken concurrently, and in deed, some processes that were traditionally undertaken much later on are increasingly being brought much forward. The idea is to identify compounds that have the highest chances of success much earlier and focus on those.

Components of drug development

The key activities involved in the development of a typical are summarised in the diagram below, showing the different tasks that are undertaken during this process. Generally, these tasks can be divided into three parts: technical; investigative and administrative.

General Perspective – New Drug Discovery and Development

The process of creating a new drug product can be broadly divided into three main phases:

  • Drug discovery – entailing the conceptualisation of the therapeutic into a molecule with known pharmacologic effects
  • Drug development – covering the steps taken to convert the molecule above into an approved and registered drug product
  • Commercialisation – which includes all the steps taken to convert the product into an approved therapeutic, launch into the market and to generate sales

These processes are schematically illustrated below, which is greatly oversimplified:

Historically, these functions were performed, respectively by the Research, Development and Marketing departments. Nowadays though, a number of these functions are outsourced to other companies that specialise in one or more aspects of these activities.

It’s worth emphasising that many activities described in the above scheme may proceed in parallel and other may spill out into other phases. For example, development activities, such as clinical trials or additional testing of formulations, generally continue well beyond registration of the drug product. Such tests may be driven by the requirement for more understanding about the new drug or the need to extend use beyond the main therapeutic applications.

The job of the discovery teams does not end with product registration and market launch. Many discovery scientists will carry out more research looking for other candidates to serves as backups in case the lead compound fails or as follow-on compounds that might have better safety or efficacy profiles over the lead compounds.

Finally, the three processes listed in the new drug development scheme above are not independent and consecutive. Rather, they are coordinated with each other because the performance of each process influences decisions taken in another stage.

Understandably, there are many competing interests as the new drug progresses through its journey. To successfully fit in and integrate all the different interests and cultures, effective project management skills are required.

Therapeutic Concept Selection

Therapeutic concept selection is about deciding whether or not to embark on a new 0project. Success at this stage is measured in terms of agreeing and signed off a drug discovery program with a clear-cut aim and timeline.

Exactly where the idea originates varies from company to company. Some companies have very strong exploratory research teams that undertake research internally and discover new knowledge on diseases and druggable targets. Others are more open minded, preferring to purchase new molecules in for further development. Often, it’s a mixture of both approaches.

Generally, the decision to select a particular program will be guided by three things: company strategy, technical capabilities and operational constraints.

  • Should the company do it? (Strategy)
  • Could the company do it? )scientific and technical capabilities)
  • Can the company deliver it? (operational constraints)

These three factors are summarised below:

Drug Discovery

The drug discovery process technically starts with choice of a disease area and a definition of the therapeutic need that should be addressed. Once this is done, the process proceeds to identification of the physiological mechanisms that need to be targeted, and ideally, identification of a specific molecular ‘drug target’.

During this phase, effort is focussed on identifying a lead chemical structure, designing, testing and fine-tuning it and ensure that it meets all the criteria required for development into a drug product.

An overview of the main stages that constitute a typical drug discovery project, from the point of identification of a target to the production of a candidate drug is shown below this process is shown below:

Discovery can at first appear like a shot in the dark. At the start, scientists will be dealing with a huge number of compounds (1020), which have to be filtered, mainly via computer simulations (in silico) into manageable number capable of being further optimised.

High throughput screening (HTS) is then applied to identify ‘HITS’ which demonstrate interesting activity. Since HTS can throw up a huge number of ‘HITS’ these are further optimised and validated to remove any artefacts or ‘noise’ from the screen.

A key aspect of validation stage is to find relationships between chemical structure and biological activity, and to find out if the compounds belong to any existing families of compounds (known as hits series).

Validated hits are therefore further studied, especially in terms of their pharmacokinetic profiles and toxicity. At this point, the number of compounds has reduced to a handful. It is these handful of substances that are subsequently entered into the lead optimisation programme.

Lead optimization is a critical process in drug discovery since it’s determines whether a suitable compound can be identified for taking forward into preclinical and clinical studies. Therefore, the goal of this stage is to scrutinise and fine-tune, typically in parallel, both the biological activity and the physicochemical properties of the lead series.

During this stage, rigorous data is generated in a precise, timely manner to quickly determine the compounds to progress the compounds, and the series, toward the ideal candidate profile. The higher the quality of these candidates, the higher the chances of successful progression into clinical trials.


The term ‘magic bullet’ was coined by Paul Ehrlich (1854 – 1915), a Germany medical scientist and winner of the Nobel Prize in Physiology or Medicine in 1908. Ehrlich envisaged a compound (the bullet) capable of attacking a pathogen and destroying it while leaving its host intact. Nowadays, pharmaceutical scientists are developing targeted and personalised cancer therapies, and these, many argue, are modern realisations of Ehrlich’s idea.

Technical development – solving technical issues related to synthesis and formulation of the drug substance with the aim of ensuring the quality and safety of the drug product. The key functions involved here are chemical, manufacturing and formulation development.

Investigative studies – establishing the safety and efficacy of the product, including assessment of whether it’s pharmacokinetically suitable for clinical use. The main function involved here are safety pharmacology, toxicology and clinical development.

Administrative functions – coordinating and managing quality control, logistics, communications and decision making to ensure high quality data are generated and to minimise any delays. The main function involved here is project management.

In addition, there will be a team coordinating and liaising with regulatory authories, collating data, liaising with material suppliers and writing dossiers for presentation to authorities in order to gain approval in a timely manner.

Pharmaceutical Development

This stage is also known as pharmaceutical development. Since pure drug substances are rarely suited for clinic use, they need to be formulated; by combining them with excipients, into tablets, capsules, injections, etc.

Pharmaceutical development refers to all the different tasks undertaken to transform the drug substance identified as a candidate during the discovery phase into a dosage form that is able to reliably deliver the drug into the body in a safe and reliable way.

Designing a formulation can be as equally time consuming and complex as drug discovery. In order to mitigate some of the issues that crop up, initial studies are undertaken during lead optimisation, before development actually starts.

For conventional drug substances, the desired route of administration is the oral route. Alternatives are considered, particularly if sufficient bioavailability cannot be achieved orally.

The different tasks undertaken in pharmaceutical development can be grouped into two:

  • Preformulation studies which specifically investigate physical and chemical properties of the drug substance, such as solubility and dissolution rates; acidity and alkalinity (pKa), chemical and physical stability, lipophilicity, particle morphology, melting point and fracture behaviour, etc.
  • Formulation studies which are essentially, chemical engineering effort aimed at converting a powder or a liquid form of the drug substance into a stable and deliverable product. During this process, formulation scientists will take into account all the known properties of the drug substance and the desired drug delivery system that best meets the therapeutic objectives of the compound.

Clinical Development

Clinical development is an umbrella terms to describe the whole set of activities undertaken by the team in support of testing of a new drug substance in humans. It includes the following clinical trials, which refer to administration into man the new drug under controlled conditions to investigate bioavailability, efficacy, safety, tolerability and acceptability.

Clinical development of new drugs has been described as both a science and an art, since it requires technical expertise, sound judgement and commercial acumen.

Executed well, clinical development brings new medicines quickly and safely to patients who need them, while also managing to return on the financial investment.

At the time of writing this post In 2021, estimates of the investment required for clinical development studies vary, but most sources agree that, including the cost of failures and capital invested, the total cost of bringing a new drug to market is $2-3 billion, spread over a 12-year development cycle. Out of this cost, two-thirds is spent on clinical development.

The clinical development process is divided into four phases, summarised in the table below.

  • Phase I: first introduction and safety assessment in man, typically in healthy volunteers
  • Phase II: early exploratory and dose-finding studies in patients
  • Phase III: large scale studies in patients
  • Phase IV: post-marketing safety monitoring of patients.

In almost every country on earth today, clinical trials are a legal requirement before a new drug can be sold or claims made for its safety of benefits. This does not include alternative remedies, however. In addition, all clinical trials, include Phase I studies, are subject to international, national and in most cases, institutional regulations.

The different international regulations and requirements are set out in guidelines published by the International Conference on Harmonisation (ICH), an organisation that was set up to harmonise pharmaceutical regulations across Europe, United States and Japan.

It is a requirement that clinical development procedures be done under ICH guidelines if the results are to be accepted for registration in the three ICH guidelines. This does not mean that the studies need to be done there – they only have to comply with these guidelines.

In addition to ICH guidelines, human studies are required to be undertaken according to an ethical framework defined code, known as the The Declaration of Helsinki (2000). This code, in a nutshell, requires the principal investigator (physician) to protect life, health, privacy and dignity.

Regulatory Affairs

A fundamental maxim in pharmaceutical new product development is the basic division of responsibilities whereby the health authority, such as the US FDA, is responsible for safeguarding the public’s health against defective and unsafe products, and the pharmaceutical company being responsible for all aspects of drug product development (quality, safety and efficacy).

The regulatory authority develops regulations and guidelines for companies and others in the value chain to follow. The approval of a pharmaceutical product is a contract between the regulatory authority on behalf of the public, and the pharmaceutical company.

The regulatory authority is responsible for approving clinical trial applications, approving marketing authorisation applications, and monitoring safety and efficacy claims of the marketed drugs. Authorities can withdraw the approval at any point where there are cases of non-compliance.

The conditions of the approval are set out in a dossier and appear in the prescribing information. Changes to these terms have to be pre-approved and authorised before they can be implemented.

Within pharmaceutical companies, the regulatory affairs department is the one responsible for obtaining approval for the new pharmaceutical product and working to ensure that this approval is maintained for as long as the company desires so.

Regulatory affairs professionals work at the interface between the regulatory authority and the project team, and they’re often the channel of communication between external and internal stake holders with respect project’s regulatory standing and progress.

Milestones and Decision Points

The decision to advance a drug candidate into early development is the first of several key strategic decision points in a new drug development project. The timing, naming and decision-making process vary from company to company, the one conceptualised below was developed by Norvatis:

Early selection point (ESP

Is the decision to take the drug candidate molecule into early (preclinical) development.

Decision to develop in man (DDM)

Is the decision to enter the compound into Phase 1, based on information obtained during preclinical development phase. Once this decision is made, the company will aim to produce between 2 and 10kg of clinical grade material.

Full development decision point (FDP)

This point is reached after Phase I and Phase IIa studies have been completed. At this point, the company has some preliminary evidence about clinical efficacy in man. From here on, the project costs skyrocket and the company must be confident on commercial returns.

Submission decision point (SDP)

This is the final point when a decision is taken to apply for registration, based on the data collected and its quality.

Summary Points about Drug Discovery and Development

Pharmaceutical companies undertake research for commercial reasons and their overarching objective is a return on capital invested. This is not to say a few companies include altruistic motives, the fact of the matter is that it takes less priority.

For this reason, the research a company pursues has to be in line with its commercial goals. Curiosity-driven research is generally left to Universities and other institutes. That said, there are territories where the two universes overlap, namely, applied research. Many recent innovations in medicine, such as monoclonal antibodies, fall into this domain, and both pharmaceutical companies, and universities have contributed to their development.

Finally, it should be stated that drug discovery and development is unlike any other type of development or innovation process, such as developing a new car. Drug discovery and development carries far greater uncertainty, and the outcome is rarely assured.

Resources Used

Pharmacentral has a strict referencing policy and only uses peer-reviewed studies and reputable academic sources. We avoid use of personal anecdotes and opinions to ensure the content we present is accurate and reliable

  • R.G. Hill, H.P. Rang, Preface to 2nd Edition, in: R.G. Hill, H.P. Rang (Eds.) Drug Discovery and Development (Second Edition), Churchill Livingstone 2013
  • Orloff et a.,l The future of drug development: advancing clinical trial design. Nat Rev Drug Discov8, 949–957 (2009).
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