Response surface optimization of cholesterol extraction from lanolin alcohol by selective solvent crystallization

A process to extract cholesterol from lanolin alcohol by selective solvent crystallization and recrystallization was developed. The crude lanosterol crystallization process was performed in methanol-acetone (3: 1, v/v) as solvent at 18 mL g(-1) liquid-solid ratio and 20.0 degrees C for 6 h. To be optimized by response surface methodology (RSM) coupled with central composite design, the process of cholesterol crystallization was carried out in acetic acid as solvent at 4.18 mL g(-1) liquid-solid ratio and 26.1 degrees C for 6 h. Under the optimized conditions, cholesterol purity was substantially improved increasing from 17.5 to 76.2%, while the purity and recovery efficiency of cholesterol increased to 94.7 and 88.0% after recrystallization, respectively.