Skin permeation of two different benzophenone derivatives from various vehicles

Synopsis The aim of this study was to determine the effects of the vehicles on the release and permeation of the UV filters. Therefore, the release and permeation of lipophilic oxybenzone and hydrophilic sulisobenzone were investigated from four different vehicles; petrolatum, o/w and w/o emulsions and hydroxyethyl cellulose (HEC) gel. Both release and permeation studies were performed by using glass diffusion cells. The vehicle in which oxybenzone has the highest released amount was petrolatum, whereas the highest released amount for sulisobenzone was obtained in HEC gel. The difference between the released amounts of oxybenzone in the other three vehicles was not significant but the released amount of sulisobenzone was least in petrolatum, whereas no significant difference was seen between o/w and w/o emulsions. The results of skin permeation experiments were similar those from release experiments. The order of permeated amounts from highest to lowest was petrolatum, o/w emulsion and HEC gel for oxybenzone, and HEC gel, o/w emulsion and petrolatum for sulisobenzone. These results demonstrate that permeation of the UV filters can be optimized by a suitable vehicle. As the percutaneous absorption of sunscreens should be avoided, the vehicle suggested for oxybenzone and sulisobenzone is o/w emulsion because of its permeation properties and cosmetic acceptance.