Temocapril-d5 is primarily used in research and analytical settings as a labeled internal standard for the quantification of temocapril and its metabolites in biological samples. Its deuterated structure allows for precise and accurate measurements using techniques such as liquid chromatography-tandem mass spectrometry (LC-MS/MS). This compound is particularly valuable in pharmacokinetic studies, where it helps in understanding the absorption, distribution, metabolism, and excretion of temocapril in the body. Additionally, it aids in the development and validation of analytical methods for therapeutic drug monitoring, ensuring the reliability of data in clinical and pharmaceutical research.