Polysorbate 20 is a mild nonionic surfactant formed by the ethoxylation of sorbitan before the addition of lauric acid which is a medium-chain fatty acid found mainly in coconut oil. It is allowed to be used as the emulsifier, detergent, dispersant, solvent and stabilizer, etc. in a number of fields such as pharmaceutical, chemical, food, textile and other industries due to its stability and relative non-toxicity.