A QUANTITATIVE ANALYTICAL METHOD FOR THE DETERMINATION OF A NEW THROMBOXANE SYNTHETASE INHIBITOR (CGS-22652) IN HUMAN PLASMA USING HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

A quantitative analytical method for the determination of a new thromb oxane synthetase inhibitor (CGS 22652) in human plasma has been develo ped using high performance liquid chromatography (HPLC). The drug and internal standard (CGS 23298) were extracted with methylene chloride a t pH 4.8. Separations were achieved by reversed phase chromatography u sing a mobile phase consisting of acetonitrile: 0.01 M citrate/phospha te buffer (pH 3.5): methanol:tetrahydrofuran (45:45:9:1, v/v/v/v), on a 5 mu m C-18 column at a how rate of 1.0 mL/min. Plasma standard curv es were linear from 50 to 2000 ng/mL, with recovery of the drug being greater than 94% at all concentrations. The method was validated over a concentration range of 50 to 2000 ng/mL, with a limit of quantificat ion of 50 ng/mL. The method was successfully applied to the analysis o f clinical samples from a single-dose safety and tolerability study co nducted in healthy male volunteers.