Photococarcinogenesis Study of Retinoic Acid and Retinyl Palmitate
Retinoic acid is the most active biological form of vitamin A, and retinyl palmitate is the major storage form of vitamin A in the skin. People cannot produce vitamin A themselves but must obtain it through the diet. Skin care products containing vitamin A are becoming popular as treatments for aging and wrinkles resulting from sun exposure.
RA [Retinoic Acid] was the first retinoid developed... and is a component of many commercial products that are advertised as being able to slow skin aging or remove wrinkles and stretch marks by increasing collagen production in the dermis.
RP [Retinyl Palmitate] is a widely used ingredient in facial makeup and skin and hair care preparations and is promoted for its beneficial effects on the appearance of skin.
The results of these preliminary experiments indicated that the incidences and severities of skin acanthosis, inflammation, and necrosis increased in a dose-related manner with the application of RA [Retinoic Acid] and RP [Retinyl Palmitate] creams to SKH-1 mice, in the absence and presence of SSL.