A Validated Enantiospecific Method for Determination and Purity Assay of Clopridogrel

Abstract

A new and accurate HPLC method using beta-cyclodextrin chemically bonded to spherical silica particles as chiral stationary phase (CSP) was developed and validated for determination of S-clopidogrel and its impurities R-enantiomer and S-acid as a hydrolytic product. The effects of acetonitrile and methanol content in the mobile phase and temperature on the resolution and retention of enantiomers were investigated. A satisfactory resolution of S-clopidogrel active form and its impurities was achieved on ChiraDex(R) column (5 mu m, 4 x 250 mm) at a flow rate of 1.0 ml/min and 17 degrees C using acetonitrile, methanol and 0.01 M potassium dihydrogen phosphate solution (15:5:80 v/v/v) as mobile phase. The detection wavelength was set at 220 nm. The method was validated in terms of accuracy, precision, linearity, and robustness. The limit of detection for R-enantiomer and S-acid were 0.75 and 0.09 mu g/ml, respectively, injection volume being 20 mu l. Finally, the molecular modeling of the inclusion complexes between the analytes and beta-cyclodextrin was performed to investigate the mechanism of the enantiorecognition and to study the quantitative structure-retention relationships. Chirality 21:878-885, 2009.