Benazepril-d5 Hydrochloride is primarily used in pharmaceutical research and development as a labeled internal standard in analytical studies. It is employed in quantitative mass spectrometry to improve the accuracy and precision of measurements when analyzing benazepril and its metabolites in biological samples. This compound is particularly valuable in pharmacokinetic studies, where it helps track the absorption, distribution, metabolism, and excretion of benazepril in the body. Its deuterated form ensures minimal interference with the natural compound, providing reliable data for drug development and therapeutic monitoring. Additionally, it aids in understanding drug interactions and metabolic pathways, contributing to safer and more effective medication formulations.