Penetration of the fragrance compounds, cinnamaldehyde and cinnamyl alcohol, through human skin in vitro

The delivery of cinnamaldehyde and cinnamyl alcohol in fragrance through human skin has been investigated by in vitro penetration studies using full thickness human skin. Cinnamaldehyde was transformed to cinnamyl alcohol and cinnamic acid in the skin. The transformation took place in model protein solution, bovine serum albumin, as well as in skin homogenates. After conjugation of cinnamaldehyde with the protein, a lag time was observed after which cinnamyl alcohol and cinnamic acid were released. On the other hand, cinnamyl alcohol was not transformed in detectable amounts to either cinnamaldehyde or cinnamic acid during penetration of the skin.