We have previously developed a cationic liposome that complies with the regulatory requirements of Japanese quasi-drug (QD) ingredients and that can thus be used as delivery system in QD cosmetic formulae. This liposome is made of soy lecithin and of a cationic protein hydrolyzate, namely Cocodimonium hydroxypropyl hydrolyzed soy protein, both of which are listed in the Japanese Standard of Quasi-drug Ingredients (JSQI)1.
In Japan, cosmetic ingredients aimed at brightening skin complexion fall under QD regulation and are restricted to the claim “suppresses melanin formation and prevents freckles caused by sunburn”. One of the most popular ingredients approved as QD-compliant active ingredient for complexion brightening purposes is ascorbyl glucoside (ascorbic acid-2-glucoside). This ingredient is claimed to downregulate melanin synthesis in melanocytes2, while being significantly more stable than native vitamin C (ascorbic acid).
In order to improve the uptake and efficacy of ascorbyl glucoside, we encapsulated it at 5% in the cationic liposome. We next assessed the ability of the ascorbyl glucoside-containing liposome to reduce melanin synthesis as compared to free ascorbyl glucoside at the same concentration. Results showed that the ability of ascorbyl glucoside to inhibit melanin production was significantly enhanced when encapsulated in the cationic liposome.
