Emerging applications of quantitative supercritical fluid chromatography-tandem mass spectrometry for chiral bioanalysis.

Individual stereoisomers of a chiral drug can possess different pharmacokinetic (PK)/pharmacodynamic (PD) properties, leading to different therapeutic/toxicological effects. Therefore, chiral bioanalytical methods are required for individual stereoisomers to assess their PK properties and potential chiral inversion in vivo. Supercritical fluid chromatography (SFC) has not been a mainstay in bioanalytical labs due to limitations of robustness/reliability of old generations of SFC instrumentation. With the significant advances of newer generation SFC instruments and chiral columns, the time is ripe for implementing this technology in bioanalytical labs, particularly for difficult analysis of chiral separations where traditional normal/reversed phase and polar organic mode chromatography are not adequate or require long run times. In this publication, we used six BMS model chiral compounds to systematically examine the key aspects of SFC-MS/MS for chiral bioanalysis (e.g., chiral columns, organic modifiers/additives). The preliminary method development results showed that SFC can provide superior chiral separations in comparison with LC. Subsequent method qualifications and validation and study sample analysis for four of these chiral compounds showed that the developed chiral SFC methods performed well and met the regulatory requirements for bioanalytical method validation and study sample analysis. Our comprehensive evaluation demonstrated that UHPSFC-MS/MS offered robust/reliable chiral assays, with good sensitivity, peak resolution, and sample throughput and is well suited for chiral separation in regulated bioanalysis.