Azilsartan-d4 is primarily used in research and development as an internal standard in analytical chemistry. It is a deuterated form of Azilsartan, which allows for precise and accurate quantification of Azilsartan in biological samples using techniques like liquid chromatography-mass spectrometry (LC-MS). This compound is particularly valuable in pharmacokinetic studies, where it helps in understanding the absorption, distribution, metabolism, and excretion of Azilsartan in the body. Additionally, it aids in the development and validation of analytical methods for drug monitoring in clinical settings, ensuring reliable measurements in patient samples. Its use is critical in ensuring the accuracy of data in studies related to hypertension treatment, where Azilsartan is a key therapeutic agent.