Excipients are inactive substances used to aid the manufacturing process and enhance the performance of the drug. They serve multiple functions:
Diluent (Filler)
Increases bulk to produce an acceptable tablet size.
Examples: Lactose, microcrystalline cellulose (MCC), dicalcium phosphate.
Binder
Promotes particle adhesion, ensuring tablet cohesion and integrity.
Examples: Starch paste, polyvinylpyrrolidone (PVP), hypromellose (HPMC).
Disintegrant
Facilitates tablet breakup or disintegration after administration for immediate release of drug.
Examples: Starch (corn, potato), sodium starch glycolate, croscarmellose sodium.
Lubricant
Reduces friction between tablet and die wall during compression and ejection.
Examples: Magnesium stearate, stearic acid, talc.
Glidant
Improves flow properties of powders or granules by reducing interparticle friction.
Examples: Colloidal silicon dioxide, talc.
Anti adherent
Prevents sticking of powder or granules to tablet punches.
Examples: Magnesium stearate, talc.
Colorants, Flavors, and Sweeteners
Enhance appearance and patient acceptance.
Ideal Properties of Excipients:
Inert and Stable: Chemically non-reactive, physically and thermally stable.
Safe and Non-toxic: Suitable for human consumption.
Compatible: Should not interfere with drug activity or stability.
Effective Functionality: Performs intended role (binder, filler, etc.).
Economical and Easy to Process: Cost-effective and supports manufacturing.
Regulatory Compliance: Meets pharmacopoeia standards.
Biocompatible: Supports drug absorption without affecting bioavailability.
Aesthetic Enhancer: Improves appearance, taste, or texture if needed.