Quantitative LC-MS/MS Methods for Characterizing Metabolites of Drugs Levofloxacin and Cyclosporin A in Human Microdose Plasma Samples

摘要

1. A sensitive LC-MS/MS method for characterizing the metabolites of cyclosporin A and levofloxacin from human microdose blood samples. 2. Cyclosporin A's metabolites AM1, AM9, and AM4N from the microdose samples were successfully quantified by tandem mass spectrometry (no use of AMS). 3. The metabolites of microdosed levofloxacin were characterized by the SIM mode with the Q1 filtering and Q3 analysis. 4. The SIM and SRM modes were able to detect only major metabolites desmethyl levofloxacin and levofloxacin n-oxide. 5. The result of the 2X2 cross-examination shows consistency that both pharmacological dose and microdose of CsA have similar but non-linear PK parameters.