LC-MS/MS-Based Bioanalytical Methods for the Quantification of Elobixibat in Human Plasma: Development, Validation, and Regulatory Perspectives

Elobixibat is a novel, minimally absorbed ileal bile acid transporter (IBAT) inhibitor approved for the management of chronic constipation and constipation-predominant irritable bowel syndrome.Due to its low systemic exposure and complex biological matrix, the accurate quantification of elobixibat in human plasma is analytically challenging yet essential for pharmacokinetic, bioavailability, bioequivalence, and clinical safety studies.Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) has emerged as the preferred technique for the bioanalysis of elobixibat owing to its high sensitivity, selectivity, and robustness.This review provides a comprehensive and critical evaluation of reported LC-MS/MS bioanalytical methods developed for the determination of elobixibat in human plasma.Key aspects of method development, including selection of biological matrix, internal standard, sample preparation strategies, chromatographic separation, and mass spectrometric detection, are discussed in detail.Furthermore, bioanalytical method validation parameters such as selectivity, linearity, accuracy, precision, recovery, matrix effect, stability, and carryover are systematically reviewed in accordance with current regulatory guidelines issued by the US Food and Drug Administration (FDA), European Medicines Agency (EMA), and the International Council for Harmonisation (ICH M10).The comparative assessment of published methods highlights variations in analytical performance, sensitivity, and regulatory compliance, thereby identifying critical challenges and best practices in elobixibat bioanalysis.In addition, the application of validated LC-MS/MS methods to pharmacokinetic and clinical studies is summarized, along with recent advancements in high-throughput and ultrasensitive bioanalytical approaches.Overall, this review aims to serve as a useful reference for researchers and bioanalytical scientists by providing practical insights into the development, validation, and regulatory acceptance of LC-MS/MS methods for the quantification of elobixibat in human plasma.