High-performance liquid chromatographic separation of the enantiomers of anti-inflammatory 2-arylpropionates: suitability of the method for in vitro metabolic studies.

The enantiomers of 2-phenylpropionic acid, 2-(2-naphthyl)propionic acid, 2-(4-biphenyl)propionic acid and six anti-inflammatory congeners were separated by high-performance liquid chromatography via their diastereoisomeric derivatives with (S)-(-)-1-phenylethylamine. In agreement with a general rule, the diastereoisomers derived from the (R)-acids are less polar and elute first. Structural factors influencing the resolution are discussed. Good calibrations were obtained for R/S ratios and total (R + S) concentrations of flurbiprofen and naproxen added to inactivated rat liver preparations. The method is suitable for in vitro metabolic studies of chiral 2-arylpropionates.