A simplified and completely automated workflow for regulated LC–MS/MS bioanalysis using cap-piercing direct sampling and evaporation-free solid phase extraction

Automated sample extraction for regulated bioanalysis by liquid chromatography/tandem mass spectrometry (LC–MS/MS) still presents significant challenges. A new sample preparation methodology with a simplified and completely automated workflow was developed to overcome these challenges using cap piercing for direct biofluid transfer and evaporation-free solid phase extraction (SPE). Using pierceable cap sample tubes, a robotic liquid handler was able to sample without uncapping or recapping during sample preparation. Evaporation for SPE was eliminated by using a mobile phase-compatible elution solvent followed by sample dilution prior to LC–MS/MS analysis. Presented here are three LC–MS/MS assays validated using this methodology to support three CNS drug development programs: (1) BMS-763534 and its metabolite, BMS-790318, in dog plasma; (2) BMS-694153 in monkey plasma; and (3) Pexacerfont (BMS-562086) and two metabolites, BMS-749241 and DPH-123554, in human plasma. These assays were linear from 1.00 to 1000 or 2.00 to 2000 ng/mL for each analyte with excellent assay accuracy, precision and reproducibility. These assays met acceptance criteria for regulated bioanalysis and have been successfully applied to drug development study samples. The methodology described here successfully eliminated all manual intervention steps achieving fully automated sample preparation without compromising assay performance. Importantly, this methodology eliminates the potential exposure of the bioanalyst to any infectious biofluids during sample preparation.