Preliminary pharmacokinetics of a new pyridopyrimidine derivative

This paper describes the preliminary pharmacokinetic studies of 4-anilino-2-methylthiopyrido[2,3-d]pyrimidine (MD-39-AM) following a single administration of the compound to male rats via different routes (intravenous and oral) in the dose range of 6-24 mg.kg-1. The plasma level versus time plots after intravenous and oral administration to male rats can well be described by an open two-compartment model. The product was rapidly absorbed and peak concentrations in plasma were reached before 1 h after a single oral administration whatever the dose studied. The absolute bioavailability calculated on the basis of AUC0-infinity after intravenous and oral administration was estimated to be about 90%. Plasma levels found at higher doses than 6 mg/kg suggest that the product kinetics is dose dependent.