Amisulpride-d5 N-Oxide is primarily used in research and development as a labeled internal standard in analytical chemistry. It is particularly valuable in quantitative analysis using techniques such as liquid chromatography-mass spectrometry (LC-MS). Its deuterated structure ensures minimal interference with the analyte of interest, allowing for precise and accurate measurement of amisulpride and its metabolites in biological samples. This compound aids in pharmacokinetic studies, drug metabolism research, and therapeutic drug monitoring, providing critical insights into the behavior and efficacy of amisulpride in clinical and preclinical settings.