Method of purifying a surfactant by ultrafiltration

摘要

A method of purifying a surfactant for use in a pharmaceutical formulation, which comprises mixing the surfactant with a solvent and bringing said mixture into contact with a semi-permeable membrane so as to allow impurities present in the surfactant and having a molecular weight lower than the molecular weight cut-off of the membrane to pass through the membrane, whilst retaining the purified surfactant.