A validated enantioselective LC-MS/MS assay for quantification of a major chiral metabolite of an achiral 11-β-hydroxysteroid-dehydrogenase 1 inhibitor in human plasma: Application to a clinical pharmacokinetic study

BMS-823778 is a potent 11-β-hydroxysteroid-dehydrogenase 1 (11βHSD-1) inhibitor and a potential therapeutic agent for type 2 diabetes mellitus (T2DM). A high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay was developed and validated to enable reliable separation and quantification of both enantiomers of a chiral hydroxy metabolite (BMT-094817) in human plasma. Following liquid-liquid extraction in a 96-well plate format, chromatographic separation of the metabolite enantiomers was achieved by isocratic elution on a Chiralpak IA-3 column. Chromatographic conditions were optimized to ensure separation of both metabolite enantiomers. Metabolite enantiomers and stable isotope-labeled (SIL) internal standards were detected by positive ion electrospray tandem mass spectrometry. The LC-MS/MS assay was validated over a concentration range of 0.200-200 ng/mL. Intra- and inter-assay precision values for replicate quality control samples were less than 9.9% for both enantiomers during the assay validation. Mean quality control accuracy values were within ±7.3%. Assay recoveries were high (>75%) and consistent across the assay range. The metabolite enantiomers were stable in human blood for 2 h on ice. The analytes were also stable in human plasma for 25 h at room temperature, 34 days at -20 °C and -70 °C, and following five freeze-thaw cycles. No interconversion of the metabolite enantiomers was detected under any bioanalytical stress conditions, from blood collection/processing through extracted sample storage. The validated assay was successfully applied to the quantification of both metabolite enantiomers in human plasma in support of a human pharmacokinetic study.