Donepezil-d 7 (hydrochloride) is the deuterium labeled Donepezil. Donepezil (E2020 free base) is a specific and potent AChE inhibitor with IC50s of 8.12 nM and 11.6 nM for bovine AChE and human AChE , respectively. In Vitro Stable heavy isotopes of hydrogen, carbon, and other elements have been incorporated into drug molecules, largely as tracers for quantitation during the drug development process. Deuteration has gained attention because of its potential to affect the pharmacokinetic and metabolic profiles of drugs. MCE has not independently confirmed the accuracy of these methods. They are for reference only.