Influence of mobile phase composition on the preparative separation of profens by chiral liquid chromatography

Liquid chiral chromatography of ketoprofen and flurbiprofen enantiomers is carried out using an amylose-based stationary phase. The mobile phases used for profens chiral separations are usually a hydrocarbon-alcohol combination, with high hydrocarbon content. However, profens show poor solubilities in hydrocarbon solvents when compared to alcohols. When the final objective is high productivity preparative separations, besides retention time, selectivity and column efficiency, solubility of the racemic drug is always a mandatory aspect to take into account. This work shows that an increase of the alcoholic content in the mobile phase is possible without a decrease in selectivity and column efficiency. Considering the chiral separation of ketoprofen and flurbiprofen enantiomers, results show that the mobile phase needs only a small quantity of acidic modifier and can be composed by a high or even pure alcoholic content. Additionally, it is found that the type of alcohol to be used can differ, depending on the profen racemic mixture to be separated