LAUSR

Abstract Although liquid chromatography-tandem mass spectrometry is the gold standard analytical platform for the quantification of drugs, metabolites, and biomarkers in biological samples, it cannot localise them in target tissues. The localisation and quantification of drugs and/or their associated metabolites in target tissues is a more direct measure of local drug exposure, biodistribution, efficacy, and regional toxicity compared to the traditional substitute studies using plasma. Therefore, combining high spatial resolution imaging functionality with the superior selectivity and sensitivity of mass spectrometry into one analytical technique will be a valuable tool for targeted localisation and quantification of drugs, metabolites, and biomarkers in tissues. Mass spectrometry imaging (MSI) is a tagless analytical technique that allows for the direct localisation and quantification of drugs, metabolites, and biomarkers in biological tissues, and has been used extensively in pharmaceutical research. The overall goal of this current review is to provide a detailed description of the working principle of MSI and its application in pharmacokinetic studies encompassing absorption, distribution, metabolism, excretion, and toxicity processes, followed by a discussion of the strategies for addressing the challenges associated with the functional utility of MSI in pharmacokinetic studies that support drug development.