Polyoxyethylene (20) sorbitan monooleate also known as Polysorbate 80, is a type of nonionic surfactant. It functions as an emulsifier, a dispersant, a wetting agent, a solubilizer, and a stabilizer in food, pharmaceutical, cosmetics, pigments, textiles, agrichemicals etc. Like other polysorbates, polysorbate 80 can be used alone or used in combination with sorbitan ester 60, 65 or 80.
Polysorbate 80 can be used as solubilizer in medicines. Research has shown that when e433 polysorbate 80 reaches a certain critical concentration, its hydrophobic parts attract to each other, which forms into micelles, where hydrophobic parts face inwards and hydrophilic parts face outwards. Micelles combine with substances that needs to be solubilized, thereby enhance the solubilities of the substances such as active pharmaceutical ingredients. To optimize solubilization, researchers have suggested to first combine polysorbate 80 with lipid-soluble pharmaceutical ingredients, then add water to further solubilize the mixture.