The pharmacokinetics of pimobendan enantiomers after oral and intravenous administration of racemate pimobendan formulations in healthy dogs.

摘要: Pimobendan is a benzimidazole-pyridazinone derivative, marketed as racemic mixture for the management of canine heart failure. Pharmacokinetics enantiomers pimobendan and its oral bioavailability have not been described in dogs. The aim this study was to describe pharmacokinetics three formulations healthy dogs: licensed capsule product, novel liquid intravenous formulations. A three-period, nested randomized two-treatment crossover design used. administered p.o. at 0.25 i.v. 0.125 mg/kg. Blood plasma samples were analysed by chromatography-mass spectrometry. Noncompartmental modelling used pharmacokinetics. Parameters compared between using general linear model. Bioequivalence tested CI90 AUC(0-∞) Cmax . Bioavailability after dosing 70%. Liquid bioequivalent only AUC. positive enantiomer (PE) had larger volume distribution than negative (NE) (281 ± 48 vs. 215 68 mL/kg; P = 0.003) shorter half-life (21.7 29.9 min; 0.004). NE distributed more quickly PE into blood cells. Enantiomers differing absorption, elimination. dogs described.