Used as a stable isotope-labeled internal standard in bioanalytical studies for the accurate quantification of acepromazine in biological matrices such as plasma, serum, and tissues. Its primary application is in pharmacokinetic and metabolism studies, where it helps distinguish the internal standard from the administered drug due to its deuterated structure. Commonly employed in mass spectrometry (LC-MS/MS) methods to ensure precision and reliability in drug detection and concentration measurement. Also useful in veterinary and forensic toxicology for confirming drug presence and monitoring exposure.