Quadrupole time-of-flight (QTof) mass spectrometry platforms have long been used in DMPK groups to understand complex metabolic pathways and provide support for key activities, including metabolic hotspot screening, generating preclinical animal and in vitro/in vivo correlation (IVIVC) information, supporting first-in-man dosing, and providing support for regulatory submission.
Advances in sensitivity, detector linear response, and robustness have opened up the possibility for QTof MS platforms to be a viable alternative for use in bioanalysis laboratories with traditional use tandem quadrupole MS platforms (also referred to as triple quadrupole, or QQQ).
Purposefully designed quantitative/qualitative analytical workflows can provide robust, reliable, and accurate quantification information on the parent compound, while simultaneously collecting additional information about metabolism or other potential pharmacodynamic (PD) markers, ultimately providing data for DMPK scientists containing accurate quantitative data with rich qualitative information to inform and drive programs.
The flexibility of QTof MS platforms for quan/qual analysis allows for both a better alignment with tandem quad MS information and workflows, and the potential to complement as well as shift workflows and assays to high resolution MS (HRMS) for value added DMPK programs. With HRMS, major metabolites can be easily detected and monitored over a time course, proving useful for determining the fate of parent compounds in vivo. Informatics packages such as UNIFI will bridge these historically disparate workflows, and provide tools to process and visualize quantitative and qualitative data simultaneously.
Quan/qual workflows with Waters QTof MS instruments demonstrate robustness and reliability for bioanalysis and metabolite identification assays, as compared with the gold-standard tandem quadrupole workflows.