DETERMINATION OF STAVUDINE, A NEW ANTIRETROVIRAL AGENT, IN HUMAN PLASMA BY REVERSED-PHASE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH ULTRAVIOLET DETECTION

A sensitive high-performance liquid chromatographic assay has been developed to determine the levels of a new antiretroviral agent. stavudine (2',3'-didehydro-3'-deoxythymidine, d4T), in human plasma. Didanosine (2',3'-dideoxyinosine, ddI) was used as the internal standard. The very selective sample pretreatment involved solid-phase extraction using silica gel columns. Chromatography was carried out on a muBondapak phenyl column, using a mobile phase of 0.005 M phosphate buffer (pH 6.8)-methanol (90:10, v/v) and ultraviolet detection at 265 nm. The method has been validated, and stability tests under various conditions have been performed. The detection limit is 10 ng/ml (using 500-mul human plasma samples). The bioanalytical assay has been used in a single pharmacokinetic experiment in a rat to investigate the applicability of the method in vivo.