Ceramide AP (CER [AP]; AP stands for α-hydroxy-N-stearoylphytosphingosine) belongs to a larger group of ceramides that are naturally occurring, long chains of lipids (fats) in the skin. To put it into perspective, the skin’s general composition of ceramides is around 50%; of that, 16% of those ceramides are of the AP variety. CERs are sphingolipids that contain a sphingoid moiety (which can be sphingosine (S), dihydrosphingosine (D), phytosphingosine (P) or 6-hydroxy-sphingosine (H)), linked with a long-chain FFA moiety (which can be nonhydroxy (N), α-hydroxy (A) or ester-linked ω-hydroxy (EO)) through an amide bond. Research indicated that CER [AP], with four hydroxyl groups on its head group, can form super stable membranes through strong hydrogen bonds. It has also been shown to be antiproliferative and proapoptotic in numerous cancer cell types in vitro. Therefore, administration of CER [AP] to the skin might help to restore the barrier function of aged and affected skin[1–2].
[1] Fitsum F. Sahle . “Polyglycerol fatty acid ester surfactant–based microemulsions for targeted delivery of ceramide AP into the stratum corneum: Formulation, characterisation, in vitro release and penetration investigation.” European Journal of Pharmaceutics and Biopharmaceutics 82 1 (2012): Pages 139-150.
[2] Fitsum F Sahle. “Lecithin-based microemulsions for targeted delivery of ceramide AP into the stratum corneum: formulation, characterizations, and in vitro release and penetration studies.” Pharmaceutical Research 30 2 (2013): 538–51.
