Amantadine-D6, a deuterated form of amantadine, is primarily used in research and analytical applications. It serves as an internal standard in mass spectrometry and other analytical techniques for the quantification of amantadine in biological samples. This helps in studying the pharmacokinetics, metabolism, and distribution of amantadine in the body. Additionally, it aids in the development and validation of analytical methods, ensuring accurate and precise measurements in clinical and pharmaceutical research. Its use is crucial in understanding drug behavior and ensuring compliance with regulatory standards in drug testing and development.