Roflumilast-d 4 N-Oxide is the deuterium labeled Roflumilast. Roflumilast is a selective PDE4 inhibitor with IC50s of 0.7, 0.9, 0.7, and 0.2 nM for PDE4A1, PDEA4, PDEB1, and PDEB2, respectively, without affecting PDE1 , PDE2 , PDE3 or PDE5 isoenzymes from various cells. 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. Form:Solid