Sensitive ex vivo human skin transdermal assay testing method with mass spectrometric analysis for cosmetics application

Abstract Background Cosmetics manufacturers are focused on cosmetic delivery systems into the skin, but the level of diffusion of the systems in the skin tissues is not well understood. The current methods, such as Franz diffusion, assess analyte diffusion in the whole skin or artificial membranes, which has limitations for understanding skin delivery systems. Aims Our study aimed to create a transdermal delivery method which is based on dermal–epidermal separation of human skin, allowing us to assess each layer of skin separately for its efficacy. Materials and Methods During the experiment, resveratrol was used as the target analyte by applying it to the skin and then separating it into dermis and epidermis. Each layer is treated individually and subjected to a high‐resolution mass spectrometry analysis to detect resveratrol levels. As a result, the efficiency of resveratrol diffusion in the dermal and epidermal layers of the skin can be evaluated. Results We found that resveratrol was detected in both the dermal and epidermal layers using our method. Conclusions Hence, we developed a sensitive method for transdermal delivery testing that can be used to evaluate skin delivery systems for cosmetic or pharmaceutical purposes.