The Chiral Bioconversion and Pharmacokinetic Analysis of Trelagliptin in Beagle Dog Plasma by LC-MS/MS.

A simple and enantioselective method was developed and validated for the simultaneous determination of (R)- and (S)-trelagliptin in beagle dog plasma by chiral liquid chromatography tandem mass spectrometry. Trelagliptin enantiomers and (R)-rabeprazole (as internal standard, IS) were extracted from plasma samples by liquid-liquid extraction and separated on a CHIRALCEL OX-3R column using acetonitrile-5 ammonium bicarbonate as the mobile phase in gradient elution mode. The multiple reactions monitoring transitions of m/z 358.1→341.2 and 359.9→150.1 were used to quantify trelagliptin enantiomers and IS, respectively. This method was validated for sensitivity, specificity, linearity, precision, accuracy and stability of specific analytes under various conditions. And it was successfully applied to evaluating the pharmacokinetic profile of trelagliptin enantiomers in beagle dogs after single intravenous administration of (R)-trelagliptin injection (at 1 mg/kg) and oral administration (at 6.7 mg/kg). In this study, no chiral bioconversion of (R)-trelagliptin to (S)-trelagliptin in beagle dog plasma was observed. The absolute bioavailability of (R)-trelagliptin was identified to be 128.2%.