Pharmacokinetics of TDP223206 following intravenous and oral administration to intact rats and intravenous administration to bile duct-cannulated rats

The pharmacokinetics of TDP223206 was studied following single intravenous and oral administrations in rats. A mixture of TDP223206 and (14)C-TDP223206 were administered to intact and bile duct-cannulated rats. Following intravenous administration, plasma concentrations declined biphasically. The AUC(inf) increased linearly with dose but was not dose proportional. The PK parameters of TDP223206 indicated low clearance (254-386 ml/h/kg) and a moderate volume of distribution (968-1883 ml/kg). The bioavailability was 32.95% and 24.46% for 10 and 50 mg/kg oral doses, respectively. (14)C-TDP223206 was distributed widely into different tissues with small intestine, liver, kidneys and large intestine having large tissue to plasma ratios. (14)C-TDP223206 was the major circulating component in the plasma. A total of 91.2% of administered radioactivity of (14)C-TDP223206 was recovered in bile indicating that biliary excretion was the major pathway for drug elimination. (14)C-TDP223206-acyl glucuronides were the major metabolites in bile. The oxo-(14)C-TDP223206 was the major metabolite in plasma and an important metabolite in bile. Two forms of diastereomeric acyl glucuronides of (14)C-TDP223206 were detected in bile with similar LC/MS intensities suggesting a similar biotransformation capacity. Only one form of these (14)C-TDP223206-acyl glucuronides was detected in plasma suggesting that enterohepatic recirculation was related to the nature of the stereo-isomers.