C18 Dihydroceramide-d3-1 (N-octadecaoyl-D-eytho-Dihydosphigosie-d3) is deuterium labeled C18 Dihydroceramide. C18 Dihydroceramide is an ester product[1].
References
[1] Russak EM, et al. Impact of Deuterium Substitution on the Pharmacokinetics of Pharmaceuticals. Ann Pharmacother. 2019 Feb;53(2):211-216. DOI:10.1177/1060028018797110