An excipient is an inactive ingredient in pharmaceutical or nutraceutical formulations that plays a vital role in drug delivery. Excipients enhance stability, improve safety, effectiveness and compliance, and ensure medications perform as intended.
The global excipients market was valued between $8.85 and $9.3 billion in 2024, and is projected to reach $14–17 billion by 2032–2034, growing at a CAGR of 5.5–7.5% (Data Bridge). With such a wide array of excipient types available, this article focuses on the most commonly used in solid oral dosage forms.
Whether you're formulating a new product or refining an existing one, understanding these components can help you develop standout solutions in a competitive market.
Excipients often serve multiple purposes in pharmaceutical formulations, from improving manufacturability to enhancing patient experience. Here are some of the key purposes:
Excipients are typically classified based on their function in the formulation. We’ve listed some of the most widely used excipients in tablets and capsules:
Binders are essential for holding the ingredients in a tablet together, ensure that the dosage form maintains its shape and integrity. They provide the necessary cohesion for granulation during the manufacturing process. Examples of binders include:
Disintegrants play a crucial role in ensuring that tablets break apart quickly when they come into contact with moisture. This rapid disintegration facilitates the release of the active pharmaceutical ingredient, promoting faster absorption. Common disintegrants include:
Lubricants are vital for the manufacturing process, reducing friction between the tablet and the machine parts during compression and ejection. They also help prevent ingredients from sticking to tablet punches and dies. Examples of lubricants are:
Glidants reduce interparticle friction and improve flow during the manufacturing process. They are typically added just prior to tablet compression. Examples of glidants are:
Diluents, also known as fillers, are used to bulk up the formulation when the active ingredient is present in small quantities. They help achieve the desired tablet size and weight. Common diluents include:
Coating agents are used to protect the tablet from environmental factors, mask unpleasant tastes, or control drug release. They can also improve the appearance and ease of swallowing. Examples of coating agents include:
These specialized excipients are designed to modify the release profile of the active ingredient, allowing for sustained or targeted drug delivery. Examples include:
These excipients combine multiple functionalities, streamlining formulation development and potentially reducing the number of ingredients needed. Examples of multifunctional excipients:
For poorly soluble drugs, excipients can significantly improve bioavailability by enhancing dissolution. Examples of solubility enhancing excipients:
When classifying excipients, their origin is also an important factor. Natural excipients, derived from plants and minerals, are generally non-toxic and valued for their biocompatibility. Synthetic excipients, by contrast, are produced through chemical synthesis. While neither type is inherently superior, growing consumer and patient demand in recent years has placed a stronger emphasis on natural ingredients.
When selecting excipients the formulator must also consider any challenges that may arise that could negatively affect the final medication. Let's explore some of the most common types of excipients, their function and formulation considerations:
|
Excipient Function |
Examples |
Primary Purpose |
Formulation Considerations |
|
Binder |
|
Hold ingredients together; provide tablet strength and integrity. |
A combination of excipients is often recommended to achieve desired tablet properties. Overly strong binding can slow disintegration; choice depends on compression properties. |
|
Diluent / Filler |
|
Add bulk to ensure appropriate tablet size and weight. |
Must be inert, compatible with API, and stable; lactose intolerance can be a concern. |
|
Disintegrant |
|
Facilitate tablet breakup in GI fluids for drug release. |
Must balance rapid disintegration with tablet hardness and stability. |
|
Lubricant |
|
Reduce friction during tablet compression and ejection. |
Excess lubricant may reduce dissolution rate and tablet hardness |
|
Glidant |
|
Improve powder flow during tablet manufacturing. |
Overuse can impact compressibility and drug uniformity. |
|
Coatings (Film / Sugar / Functional) |
|
Protect drug from moisture and oxygen, mask taste, aid swallowing, control release, aid identification and improve patient compliance. |
Interactions with APIs must be considered. Functional coatings (enteric, sustained release) require precise formulation. |
|
Multifunctional Excipients |
|
Enhanced binding and flow. Reduces moisture uptake thus improving stability. Reduces or eliminates the need for binders and superdisintegrants and minimizes levels of lubricants and glidants needed in the formulation. |
Upgrading to multifunctional excipients may require some investment but formulation and manufacturing becomes less complex. |
|
Control Release |
HPMC can be used within the core tablet to modify drug release. Coatings like Surelease and Ashakote can be applied to the tablet core to modify release. Newer excipients like Corelease reduce manufacturing steps in osmotic tablet formulations. |
Controlling release increases complexity as it requires precise formulation. |
|
| Solubility Enhancing Excipients |
|
Improve bioavailability of poorly soluble drugs without physically modifying the API. |
Expensive, adds complexity to formulation, requires specialized knowledge. |
Formulators select excipients based on their functionality, ensuring they support the dosage form’s performance as fillers, binders, stabilizers, or other roles. Compatibility with the API is essential to maintain stability and bioavailability, while safety and toxicity profiles guide the use of excipients with well-documented tolerability. Each choice must align with the route of administration, as requirements differ for oral, topical, or parenteral products.
In addition, excipients must comply with pharmacopeial and regulatory standards (e.g., USP, Ph. Eur.) to ensure quality and acceptance in global markets. Practical considerations like quality, cost, supply reliability, and ease of sourcing affect feasibility, while manufacturing constraints like processing method or equipment compatibility influence consistency. Balancing these criteria helps formulators design drug products that are safe, effective, and commercially viable.
There is increasing interest in multifunctional excipients that can reduce formulation complexity, increase manufacturing efficiency and enhance patient compliance. Advances in nanotechnology and biopolymer-based materials are driving innovation, offering new opportunities for controlled release and precision drug delivery.
Regulatory acceptance of new excipients remains a challenge, but initiatives like the FDA’s Novel Excipient Review Pilot Program are opening pathways for innovation. Sustainability and supply chain resilience are also shaping selection, with formulators seeking greener, renewable, and more reliable sources. Digital tools, like Colorcon’s Hyperstart C2C™ service are now routinely used to reduce development time. Together, these trends are shifting excipient selection toward more advanced, sustainable, and patient-focused solutions.
The world of pharmaceutical excipients is vast and continually evolving. From traditional binders and disintegrants to cutting-edge multifunctional and bioadhesive excipients, the choices available to formulators are more diverse than ever. By carefully selecting and combining these ingredients, pharmaceutical companies can create innovative, high-performance products that meet the needs of both patients and healthcare providers.
Remember that the right choices can significantly impact your product's efficacy, stability, and market success. Stay informed about the latest developments in excipient technology, and don't hesitate to explore novel options that could give your formulations a competitive edge. With the right blend of science and innovation, your next pharmaceutical product could set new standards in drug delivery and patient care.