SIMPLE, RAPID AND SENSITIVE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC DETERMINATION OF DELAVIRDINE AND ITS N-DESISOPROPYL METABOLITE IN HUMANPLASMA

A method for the determination of a bisheteroarylpiperazine, non-nucle oside HIV-1 reverse transcriptase inhibitor, delavirdine, and its N-de sisopropyl metabolite in human plasma, is described. Samples were depr oteinized by addition of two parts of a solution of internal standard in acetonitrile (1 mu g/ml) to one part plasma. The supernatant was di luted with 10 mM phosphate buffer, pH 6.0, and injected onto the HPLC system. Fluorescence of the eluent was monitored with excitation at 30 2 nm and emission at 425 nm. Quantitation of delavirdine and its metab olite was achieved by comparing the peak-height ratio of each componen t relative to the internal standard to a through-the-origin linear reg ression curve determined from fortified plasma calibration standards. The assay was linear over the concentration range 0.02-17 mu M for bot h delavirdine and its metabolite. The precision of the method, as expr essed by the mean C.V. of the back-calculated, non-zero, standard conc entrations, was +/- 4.4% for delavirdine and +/- 4.3% for the metaboli te. The assay has been validated and utilized to analyze samples from human and animal pharmacokinetic studies.