What is the form and concentration of VC in skin care products?

VC and VC body used in skin care products are difficult to be directly applied to skin care products for the following reasons: strong reducibility, easy oxidative inactivation by oxygen in the air, unstable chemical properties, slightly higher temperature, metal ions and sunlight, and low pH environment that easily leads to inactivation of VC, and direct use in skin care products is very irritating to the skin, so there are two commonly used methods: liposome encapsulation. . The wrapped VC is not in direct contact with air, which prolongs the shelf life and reduces the irritation to the skin. Make VC derivatives and add them to skin care products. The storage period of VC can be extended by using the insensitivity of VC derivatives to the environment. But if you want to have an effect on the skin, you need a VC body, and it is not enough to have a derivative of VC itself. Therefore, whether the VC derivative is effective depends on two points: 1) how effective the VC derivative in the product is in penetrating the skin; 2) What is the efficiency of transforming VC derivatives into VC bodies after penetrating the skin? At present, the products added with VC derivatives in the market mainly use the following types: water-soluble type: sodium ascorbate phosphate, magnesium ascorbate phosphate, ascorbate glucoside (AA-2G) and ascorbate lactulose; Oil solubility: ascorbyl palmitate, esterified vitamin C (VIP) and lipophilic: ascorbyl ether.