Cremophor® EL is prepared by reacting 35 moles of ethylene oxide with each mole of castor oil. Cremophor EL is a synthetic, nonionic surfactant. Its utility comes from its ability to stabilize emulsions of nonpolar materials in aqueous systems.
Cremophor® EL is mixture of polyoxyethylated triglycerides, by reacting castor oil with ethylene oxide in a molar ratio of 1:35, that acts as a nonionic surfactant and serves as a formulation vehicle for poorly-water soluble pharmacological agents.