VC magnesium phosphate (MAP) is a kind of salt with neutral and stable PH value. The phosphate ester group is located at the second point of the ring. On the one hand, it protects it from oxidation, and on the other hand, it prevents its volatile oxidation. Therefore, their efficacy depends on whether they are converted into ascorbic acid. Under basic conditions, L-ascorbic acid has very low passive permeability, while MAP is more likely to penetrate into the dermis, and where it is converted into L-ascorbic acid, The difference in permeability may be due to the hydrophilicity of L-ascorbic acid and the lipophilicity of MAP. In the study of human fibroblasts in vitro, MAP and L-ascorbic acid have the same ability to stimulate collagen synthesis. However, SAP requires at least 10 times the concentration to achieve the same effect. Compared with stable MAP, it is superior to vitamin C, and its percutaneous absorption is far inferior to vitamin C, MAP has proved that it can be converted…