Abstract
A novel amphiphilic hydroquinone derivative having a C18 alkyl chain phosphate attached to the hydroquinone (HQ) moiety was chemically synthesized. The thermal stability, distribution between organic and aqueous phases, and in vitro skin permeability were evaluated. This HQ derivative was identified as disodium p-phenylene diisostearyl diphosphate (HQ-2P2IS) by UV, infrared, mass, and nuclear magnetic resonance spectroscopies. Product HQ-2P2IS was obtained in good yield (56%), and it exhibited satisfactory stability in neutral solution, comparable to that of HQ. Its skin permeability was also higher than that of HQ. HQ-2P2IS is susceptible to enzymatic hydrolysis by tissue phosphatase, which releases HQ in the skin tissues. Thus, these characteristics indicate that the novel hydroquinone derivative presented herein, i.e., HQ-2P2IS, may serve as an effective pro-hydroquinone for skin care applications.
