A SELECTIVE AND SIMPLE RP-HPLC ASSAY TO QUANTIFY ALBENDAZOLE METABOLITES IN PLASMA

A high performance liquid chromatographic (HPLC) method for the resolu tion of the two main metabolites of albendazole (ABZ): albendazole-sul phoxide (ABZ-SO) and albendazole-sulphone (ABZ-SO2) is proposed and co mpared to other methods previously reported. Results are presented for the linearity, reproducibility, and sensitivity of these two metaboli tes. This method is useful in pharmacokinetic studies of ABZ and ABZ-S O. One example of the possible application of this HPLC assay method i n pharmacokinetic studies is provided ABZ-SO and ABZ-SO2 were evaluate d in plasma samples of mice after oral administration of a liquid form ulation of ABZ-SO (50 mg/kg). During the 6 hours following oral admini stration to mice ABZ-SO concentrations were higher than ABZ-SO2. Cmax for ABZ-SO was achieved in less than 60 minutes after oral administrat ion.