Retinyl Acetate

What is retinyl acetate?

Retinyl acetate is the acetate ester of retinol. It can be chemically synthesized from retinol (R), and it can also be produced by metabolically engineered E. coli, along with other retinoids such as retinol and retinal (R). The first commercial batches of retinyl acetate were produced in 1948 by Roche, the Swiss multinational healthcare company (R).

Is retinyl acetate stable?

Like retinyl palmitate, retinyl acetate is often used in cosmetic products because of its superior thermal stability over retinol (R). It does however decompose under photoirradiation, forming isomers of anhydroretinol (R), which may result in the generation of reactive oxygen species that lead to oxidative damage R).

The photostability of retinyl acetate can be improved by encapsulating it in nanoparticles made of UV absorptive chitosan, and its stabiilty in water can be enhanced through encapsulation in ethyl cellulose nanoparticles (R).

Does retinyl acetate get absorbed?

There is evidence that retinyl acetate is capable of penetrating the skin. Although it did not appear to be absorbed through rabbit ear skin (R), it has been shown to permeate, albeit slowly, through reconstructed human epidermis (R). Experiments on pig ear skin also found low amounts of retinyl acetate in the stratum corneum, epidermis and dermis following topical application (R, R).

Lemon essential oil enhances the release of retinyl acetate from topical emulsions and its flux across the skin by 5.8x (R). Encapsulation of retinyl acetate in nanoparticles on the other hand seems to significantly slow its absorption rate, but results in retention of retinyl acetate in the hair follicles, through which retinyl acetate can diffuse into the dermis (R).

What happens after retinyl acetate is absorbed?

While retinyl acetate was not hydrolysed after being applied to rabbit ear skin (R), retinyl acetate applied to pig ear skin was found to be accompanied by retinol in the stratum corneum and epidermis, providing evidence that it is hydrolysed to retinol (R).