SENSITIVE REVERSED-PHASE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC METHOD FOR THE DETERMINATION OF ATEVIRDINE AND ITS N-DESETHYL METABOLITE IN HUMAN SALIVA OR CEREBROSPINAL-FLUID USING SOLID-PHASE EXTRACTION

A sensitive reversed-phase high-performance liquid chromatographic met hod for the determination of atevirdine and its primary metabolite in human saliva or cerebrospinal fluid using solid-phase extraction is de scribed. Samples mixed with internal standard and sodium phosphate buf fer were applied to an activated C-18 solid-phase extraction column. T he reconstituted eluate was injected onto a Zorbax RX C-8 column utili zing a mobile phase of 100 mM ammonium acetate (pH 4.0)-isopropyl alco hol-acetonitrile (55:20:25, v/v/v). Fluorescence detection was employe d with excitation at 295 nm and emission at 456 nm. Quantitation was a chieved using peak-height ratios. The detection response curve was lin ear from 2 to 850 nM for atevirdine in both human saliva and cerebrosp inal fluid and from 2 to 250 nM for the metabolite in human saliva. Th e method was utilized to analyze cerebrospinal fluid and saliva sample s from clinical studies.