As a popular oil-soluble ascorbyl ester, tetrahexyldecyl ascorbate (THDC), trademarked by Sytheon as VitaSynol C, not only improves chemical stability, but its lipophilic nature also facilitates delivery into the epidermis and dermis where it undergoes intracellular enzymatic conversion to free ascorbic acid. Importantly, as noted by Sytheon, free ascorbic acid must be released by THDC before its skin benefits can be realized. Thus, THDC is a precursor of ascorbic acid.
Previous research: Sytheon Finds Aryl Alkanones Protect Hair Against Dye-induced Damage
Previously, THDC (CAS # 183476-82-6) and ascorbyl tetraisopalmitates (CAS # 183476-6) were construed as being equivalent structures when in fact they represent two different chemistries with different CAS numbers. While both are esters of ascorbic acid, THDC comes from a reaction with 2-hexyldecanoic acid whereas ascorbyl tetraisopalmitates are derived from a reaction with isopalmitic acid. Therefore, they are two different fatty acids that, when esterified with ascorbic acid, yield two products.
This misnomer was corrected by Sytheon working in close collaboration with the Personal Care Product Council (PCPC) and the Chemical Abstract Services (CAS # provider). Recently, Sytheon has also demonstrated that the stability of THDC under an oxidant-rich environment and its skin benefits can be improved by combining it with Synoxyl AZ (INCI: Acetyl Zingerone). This work was published in the International Journal of Molecular Sciences.