Pharmaceutical excipients are auxiliary substances in drug formulations-excluding the active pharmaceutical ingredient (API)-that possess no direct therapeutic effect but exert a significant influence on the quality, safety, and efficacy of the medicinal product.
Core Structural and Carrier Functions
Serve as excipients and carriers, providing the necessary volume and physical form to a drug (e.g., lactose or starch in tablets).
Facilitate the manufacturing, packaging, and transport processes, transforming raw materials-such as powders or liquids-into usable dosage forms.
Ensure uniformity in the appearance of the formulation and accuracy of the dosage, preventing the uneven distribution of the active ingredient.
Enhancing Drug Stability
Protect drugs against oxidation, hydrolysis, or deliquescence, thereby extending shelf life.
Adjust the pH and osmotic pressure of liquid formulations, preventing the precipitation or degradation of the drug during storage.
Stabilize protein and peptide-based drugs, preventing them from aggregating, decomposing, or losing their biological activity.
Improving Absorption and Release Characteristics
Enhance the solubility of poorly soluble drugs through solubilization or co-solubilization, thereby increasing bioavailability.
Act as disintegrants or release-retarding agents to control the rate of drug release, enabling immediate-release, sustained-release, or targeted-delivery effects.
Certain surfactant-based excipients can facilitate the penetration of drugs across mucosal barriers, improving absorption efficiency.
