What are Excipients?

Excipients are the inert components in pharmaceutical formulations that serve diverse functional roles within the product. This includes everything from compositions of medications and medical devices to various cosmetic items or nutraceutical supplements, excluding the active ingredient(s).

Mostly, excipients feature minimal to no pharmacological activity, unlike the active pharmaceutical ingredient (API). To ensure the safety of excipients and API, it is necessary to use different approaches for evaluating their risk-to-benefit ratio and anticipated biological effects, given the significant differences between the two.

Each excipient has a defined purpose within a dosage form, such as binding, promoting disintegration, or adjusting pH, to ensure its efficient functionality. The stability of the final dosage form is highly impacted by the selection and concentration of excipients and their interactions with the active compound and each other. They can help in drug absorption, reduced viscosity, or improved solubility.

Types of Excipients in Pharmaceutical Formulations

Various excipients play a critical role in improving the properties and performance of pharmaceutical formulations. Among them, here are some of the most prominent and frequently used excipients:

Microcrystalline Cellulose

Microcrystalline Cellulose is a purified, partially depolymerized cellulose. It is a white, odorless, tasteless, crystalline powder. It comes in different grades distinguished by particle size, density, and moisture levels. It primarily functions as a binder-diluent, adsorbent, anti-adherent, tablet disintegrant, and suspending agent.

Magnesium Stearate

Magnesium and solid organic acids are used as a lubricant in tablet and capsule manufacturing. It is widely used in cosmetics and pharmaceutical products and is a hydrophobic ingredient to repel moisture.

Pharmaceutical Polymer Coatings

The coating of solid dosage forms is now a standard practice in the pharmaceutical industry. They are used for aesthetic appeal, moisture control, or modulation of drug release. They can be divided into three broad groups: conventional pharmaceutical coatings, functional pharmaceutical coatings (non-release modifying), and functional pharmaceutical coatings (release-modifying).

Croscarmellose Sodium

Croscarmellose Sodium is also regarded as crosslinked carboxymethyl cellulose. It is a leading disintegrating agent in solid dosage forms. It is widely recognized for its consistent performance, compatibility with various active ingredients, and compliance with direct compression, wet granulation, roller compaction, and capsule filling.

Silicified Microcrystalline Cellulose

It is a co-processed pharmaceutical excipient. SMCC manifests as either a white to off-white, odourless powder or a fibrous substance. SMCC serves diverse roles as a thickening agent, stabilizer, and emulsifier in the food industry. Its film-forming ability makes it valuable in pharmaceutical formulations.

Lactose Monohydrate

This excipient is extracted from mammalian milk. It is a natural disaccharide that serves as a tablet and capsule filler diluent, a lyophilization aid in injectable products, and an extender/filler in tablet coatings. Lactose monohydrate is beneficial because of its multiple properties, including high compatibility with active pharmaceutical ingredients and adaptability to different formulator needs.

Calcium Stearate

Calcium stearate is an alkaline compound derived from the carboxylic acid salt of calcium, categorised as a type of calcium soap. It is a white waxy powder. Due to its versatile properties, it is used as a lubricant, release agent, anti-caking agent, emollient, and stabilizer in varied applications.

Stearic acid

Stearic acid is a saturated fatty acid, generally found in vegetable and animal fats. It is a soft waxy solid that is often used in various industries such as cosmetics, pharmaceuticals, and food production. The chemical formula of stearic acid is CH3(CH2)16CO2H. It is known for its ability to act as an emulsifier, stabilizer, and thickener in products like lotions, soaps, and candles.

Sodium Starch Glycolate

It is a Modified potato starch excipient that is a super disintegrant. It is widely recognized for its adaptability and compatibility with many active pharmaceutical ingredients and processing technologies.

Calcium Silicate

Calcium silicate is a white, easily flowing powder. It is obtained from naturally-occurring limestone and diatomaceous earth, a type of siliceous sedimentary rock. It is commonly used as an anti-caking agent, a food additive, and a reinforcing agent in various products. It is employed in the manufacturing of ceramics, paints, and pharmaceuticals.

Sodium Bicarbonate

Sodium Bicarbonate, also known as sodium hydrogen carbonate (NaHCO₃), is a simple chemical substance with the molecular formula 84.01. It is referred to as carbonic acid monosodium salt. It is an odorless, white, crystalline powder with a salty, alkaline taste. It helps maintain the alkaline pH in formulations. It is a buffering agent and a sodium ion donor in various dosage forms. It is utilized therapeutically in antacid formulations, managing metabolic acidosis and contributing to oral rehydration salts.

Sodium Stearyl Fumarate

It is a sodium salt of fumaric acid octadecyl ester. It is presented in a fine, white powder form. It functions as a lubricant for tablets and capsules. It is mainly used in formulations where traditional lubricants like magnesium stearate or stearic acid pose challenges, such as prolonged dissolution or strain-rate sensitivity.

Pregelatinized Starch

Pregelatinized starch (PGS) refers to starch that has already undergone gelatinization. It is a common food additive that serves as a thickening and gelling agent in various food products. It is typically found in the form of a white, odorless, and tasteless powder composed of small spherical or oval granules. This starch can be sourced from maize (corn), potato, wheat, or a combination of these.

Maize starch

Maize Starch is extracted from corn (Zea mays) and is a multifunctional excipient. It is a tablet and capsule diluent, disintegrant, and binder. Starch consists of two polymers, amylose, and amylopectin, based on α-D-glucose. Despite the availability of newer and superior excipients, starch remains one of the most commonly used tablet binders, disintegrants, and fillers today.

Mannitol

Mannitol is a hexahydric alcohol isomeric with sorbitol. It is a white, odorless, crystalline powder or free-flowing granules. It has a sweet taste and imparts a cooling sensation on the tongue. It is widely adapted as an excipient in tablet formulation. It is a diluent for both capsules and tablets making it highly suitable for buccal tablets. It has a non-hygroscopic nature, excellent compressibility, and overall inert properties.

Conclusion

To sum it up, excipients are essential ingredients besides active drugs in pharmaceutical products. They give bulk and form to solid medications like tablets and capsules. For better manufacturing, excipients help bind, break apart, lubricate, and coat formulations. Mannitol is an exceptional excipient that compresses well for making tablets/capsules and does not absorb moisture, allowing a longer product lifespan. Excipients control how drugs are released and improve dissolution, absorption, taste, and appearance. Carefully chosen excipients turn unstable drugs into well-made, user-friendly products that follow regulations.to sum it up,

We are an exceptional quality excipient manufacturer with over 25 years of experience. We at APB consist of an FDA & FSSAI approved in-house R & D Laboratory. We have served 1000+ clients and therefore have a precise understanding of customer’s unique requirements. We develop excipients for diversified use in pharmaceutical industries. We are continually in pursuit of improving the quality standard of our products. Connect us to experience superior quality products.