Modulation of chromatographic performances of HSA-based HPLC column by reversible binding of lithocholic acid

The performance of a HSA-based HPLC column has been improved by modulating the binding properties of the anchored protein using lithocholic acid as a selective modifier in the mobile phase. In particular, retention decreased for both drugs binding to sites I or II, while the enantioselectivity was maintained for most analytes. The advantages of using lithocholic acid in the mobile phase were impressive in the case of profens, for which a considerable reduction in analysis time and a significant increase in enantioselectivity were obtained. The results were rationalized by considering lithocholic acid as a direct competitor for site II binding drugs and indirect competitor for site I binding drugs.