LC–MS/MS-BASED APPROACHES FOR METABOLITE IDENTIFICATION AND QUANTIFICATION OF VONOPRAZAN: A COMPREHENSIVE REVIEW

Abstract

Vonoprazan is a potassium-competitive acid blocker (P‑CAB) that has rapidly emerged as an alternative to proton pump inhibitors for the management of acid‑related disorders and Helicobacter pylori eradication therapy. Its extensive hepatic metabolism via cytochrome P450 (CYP) enzymes and sulfotransferases generates several major metabolites, including M‑I, M‑II, M‑III, and the sulfate conjugate M‑IV‑Sul, which have important implications for efficacy, safety, and drug–drug interaction (DDI) risk. Liquid chromatography–tandem mass spectrometry (LC–MS/MS) has become the method of choice for quantitative determination of vonoprazan and its metabolites in biological matrices and for structural elucidation in in vitro and in vivo metabolism studies. This review summarizes LC–MS/MS-based bioanalytical and metabolite identification approaches applied to vonoprazan, covering method development and validation in plasma, urine, liver microsomes and hepatocytes, strategies for simultaneous quantification of parent drug and multiple metabolites, and applications in pharmacokinetic, bioequivalence and DDI studies. Particular emphasis is placed on multiple‑reaction monitoring (MRM) methods, sample preparation workflows, regulatory validation parameters, and emerging trends such as green analytical chemistry and stable‑isotope internal standards. Finally, current gaps and future directions are discussed, including the need for more comprehensive metabolite profiling in humans, standardized reporting of metabolite exposure, and integration of LC–MS/MS data into mechanistic modeling frameworks.