Emulsion stabilizer

Emulsion stabilizers are a broad class of pharmaceutical excipients, rather than therapeutic targets, that prevent the separation of immiscible liquid phases in a formulation [FDA, Inactive Ingredient Database]. They function by adsorbing at the oil-water interface to reduce interfacial tension or by providing steric and electrostatic stabilization that prevents droplet coalescence [PubChem; Handbook of Pharmaceutical Excipients]. These substances are critical for ensuring the physical stability, shelf-life, and dosing uniformity of liquid and semi-solid dosage forms. Common stabilizers include synthetic surfactants like polysorbates (e.g., Tween 80), natural phospholipids like lecithin, and polymers such as carbomers or cellulose derivatives [NCBI, PMC6010116]. Although they are pharmacologically inactive in terms of treating a primary disease, they play a vital role in drug delivery by enhancing the solubility and bioavailability of hydrophobic active ingredients. As they are functional formulation components rather than biological molecules involved in disease pathways, they are not classified as therapeutic targets in the conventional sense [NIH, National Center for Biotechnology Information].

Other names

Emulsifying agentStabilizing agentSurfactantEmulgentSurface-active agent

Reduction of interfacial tension and creation of physical or electrostatic barriers to prevent droplet coalescence in emulsion-based drug delivery systems.