HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC DETERMINATION OF (-)-BETA-D-2,6-DIAMINOPURINE DIOXOLANE AND ITS METABOLITE, DIOXOLANE GUANOSINE, USING ULTRAVIOLET AND ONLINE RADIOCHEMICAL DETECTION

(-)-beta-D-2,6-Diaminopurine dioxolane (DAPD) and its metabolite dioxo lane guanosine (DXG) have potent activity against hepatitis B virus an d Hn! in vitro. A reversed-phase HPLC analytical method using UV and o n-line radiochemical detection for the determination of DAPD and DXG i n monkey serum and urine is described in this report. Retention times for DXG, DAPD and internal standard (2',3'-didehydro-2'deoxythymidine, D4T) were 5.0, 6.0 and 13.0 min, respectively. The extraction recover y was greater than 97% for DAPD and 94% for DXG. The limit of quantita tion for UV detection was 100 ng/ml and 125 ng/ml for DXG and DAPD in monkey serum. The standard curves were linear from 0.1 mu g/ml to 5 mu g/ml for DXG and 0.125 mu g/ml to 5 mu g/ml for DAPD. For radiochemic al detection, calibration curves of standard solutions of DAPD and DXG were linear in the range of 3500 Bq to 32 000 Bq and 7500 Bq to 60 00 0 Bq. The intra- and inter-day relative standard deviations were less than 7.2% using UV and less than 8.6% using on-line radiochemical dete ction. The HPLC method was applied to serum and urine samples collecte d from a male rhesus monkey that was administered 33.3 mg/kg DAPD with 200 mu Ci of [H-3]DAPD intravenously.