DETERMINATION OF PIROXICAM AND ITS MAJOR METABOLITES IN THE PLASMA, URINE AND BILE OF HUMANS BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

A simple and sensitive liquid chromatographic method with ultraviolet detection is described for the determination of the non-steroidal anti-inflammatory drug piroxicam and its major metabolites in human plasma, urine and bile. Separation of these components occurs on a reversed phase C-10CN column with a mobile phase consisting of acetonitrile-water-sodium dihydrogenphosphate solution. The detection limit of the assay was 50 ng/ml with intra- and inter-assay coefficients of variation for piroxicam of the order of 2 and 5%, respectively. The assay linearity was good (typically r = 0.9999). This method can be readily utilised for clinical pharmacokinetic and mass-balance studies.