9.6.3.3　Nanoemulsions

Nanoemulsions are a combination of a surfactant with an oil or water phase.Depending on the composition，nanoemulsions have different types，such as oil in water，water in oil，and bicontinuous nanoemulsions.They exhibit various sizes ranging from 50 nm to 200 nm.They have very low oil/water interfacial tension and a lipophilic core，which is surrounded by a monomolecular layer of phospholipids.These properties make it more suitable for the delivery of lipophilic compounds.Nanoemulsions show several advantages，including low viscosity，high kinetic stability，high interfacial area，and high solubilization capacity.In cosmetics formulation，nanoemulsions provide rapid penetration and active transport of active ingredients and hydration to the skin.(https://www.daowen.com)