Pharmaceutical excipients play a crucial role in the formulation and production of drugs, supporting their stability, efficacy, and palatability. Among the numerous excipients used in pharmaceutical preparations, preservatives, stabilizers, suspending agents, thickener excipients, and flavoring agents are commonly observed. Understanding their functions and characteristics is essential for pharmaceutical scientists and formulators. In this article, we will delve into each of these excipients to gain a comprehensive understanding of their roles in drug formulation.


Preservatives are vital components in pharmaceutical formulations as they safeguard against microbial growth and ensure product safety during its shelf life. One frequently employed preservative is benzoic acid, which exhibits excellent antimicrobial properties and is used in various oral and topical formulations. Benzoic acid prevents microbial contamination, particularly in liquid dosage forms such as syrups, suspensions, and emulsions.


Stabilizers are excipients used to maintain the integrity and stability of drug formulations, preventing chemical degradation, oxidation, or hydrolysis of active ingredients. Polyoxyl 35 castor oil is mainly used as an emulsifier and solubilizer, especially suitable for the preparation of aqueous solutions containing volatile oils, fat-soluble vitamins, and other hydrophobic substances.

Suspending Agents

Suspensions are commonly administered in oral dosage forms that consist of solid particles dispersed in a liquid medium. Suspending agents are crucial in maintaining the uniform distribution of these particles to ensure proper dosing. Sodium starch glycolate is widely used in oral pharmaceuticals as a disintegrant in capsule and tablet formulationscommonly employed in tablets prepared by either direct compression or wet granulation processes.

Thickener Excipients

In some pharmaceutical formulations, thickener excipients are included to enhance viscosity and improve the texture of the product. Maltodextrin is used in tablet formulations as a binder and diluent in both direct compression and wet granulation or agglomeration processes.

Flavoring Agents

Flavoring agents are crucial in oral pharmaceutical formulations as they enhance palatability and mask any unpleasant taste or odor. Clove oil is a commonly used flavoring agent that possesses a pleasant and distinct aroma. It is particularly beneficial in oral formulations such as mouthwashes and toothpastes, effectively masking the taste of other ingredients. Clove oil offers not only a refreshing sensation but also therapeutic benefits, such as antiseptic and analgesic properties.


Pharmaceutical excipients such as preservatives, stabilizers, suspending agents, thickener excipients, and flavoring agents play integral roles in ensuring the effectiveness, stability, and palatability of drug formulations. Hence, the careful selection and utilization of these excipients are crucial in pharmaceutical formulation. By understanding the functions and characteristics of these commonly seen excipients, pharmaceutical scientists can optimize drug formulations for better patient outcomes.