A high-performance liquid chromatographic method for the simultaneousdetermination of KR-008 and its metabolite in biological fluids was developed The samples wereinjected directly without further treatment,the compounds were separated and analysed on a reversed-phase column under isocratic conditions,including ion pairing.Concentrations in urine and bile weredetermined by an external standard method.The detection limit was 0.8μg/ml in urine.Preliminarydata showed that,following i.p.administration(120mg/kg)of KR-008 to rats,approximately 2.8% ofthe dose was excreted in urine as unchanged compound and more than 8.9% was as a metabolite;inbile it was 0.73% excreted as unchanged form and above 0.29% as the metabolite.The peak biliaryconcentration of KR-008 was 0.39mg/ml at 20min after dosing. A high-performance liquid chromatographic method for the simultaneous determination of KR-008 and its metabolite in biological fluids was developed The samples were injected directly without further treatment, the compounds were separated and analyzed on a reversed-phase column under isocratic conditions, including ion pairing. Concentrations in urine and bile were determined by an external standard method. The detection limit was 0.8 μg / ml in urine. Preliminary data showed that, following ipadministration (120 mg / kg) of KR-008 to rats, approximately 2.8% of the dose was excreted in urine as unchanged compound and more than 8.9% was as a metabolite; inbile it was 0.73% excreted as unchanged form and above 0.29% as the metabolite.The peak biliaryconcentration of KR-008 was 0.39 mg / ml at 20 minutes after dosing.