The stereoselective pharmacokinetics of the desmethyl‐phencynonate hydrochloride in beagle dogs.

The aim of this study was to investigate the chiral inversion and the stereoselective pharmacokinetic profiles of desmethyl‐phencynonate hydrochloride after administration of the single isomer and its racemate to beagle dogs. A liquid chromatography with tandem mass spectrometry (LC–MS/MS) method was established for determination of the stereoisomers on chiral columns in beagle dog plasma, which met all the requirements. The chiral inversion in dogs of the desmethyl‐phencynonate hydrochloride were studied after administration of the single isomer or the racemic modification. The stereoselective pharmacokinetic profiles of the desmethyl‐phencynonate hydrochloride were studied by assays for simultaneous isomers after administration of the racemic modification. The results showed that the absorption of the R-configuration dosed as the single isomer was higher than it dosed as the racemic modification. The AUC(0‐t), AUC(0‐∞), and Cmax of the S-configuration were much higher than those of R-configuration after oral administration of the racemic desmethyl‐phencynonate hydrochloride. The chiral inversion of desmethyl‐phencynonate isomers could not occur in dogs after administration of the R-configuration. [ABSTRACT FROM AUTHOR]