Pharmacokinetics of besulpamide in rats and dogs

The pharmacokinetics of besulpamide were studied in rats and its urinary excretion in rats and dogs. Kinetic characteristics were the same for both male and female rats according to a two-compartment open model. Biological half-life was 1-4 hr, absorption half-life was approximately 10 min and absolute bioavailability was nearly complete (F = 86.4%). In rats, urinary excretion of unchanged besulpamide was 30% after i.v. administration and 7% after oral administration, whereas in dogs after oral administration it was 54%. Values of the area under the plasma concentration-time curve in rats and percent of urinary excretion in dogs show that the kinetics of besulpamide are not dose-related when the drug is administered at doses of 10-50 mg/kg.