Research on Permeation Influencing Factors of Cosmetics UV Filters and Improve In Vitro Permeation Tests (IVPTs)

Abstract

The ideal UV absorber should be safe and should have excellent properties. Therefore, transdermal absorption is essential for the safety risk assessment of sunscreen cosmetics. The Franz diffusion cell method is the most common means of studying in vitro penetration, but there is a lack of standard methods for the in vitro permeation of UV absorbers. This paper used the Franz diffusion cell method to improve an in vitro permeation test (IVPT) for UV absorbers; three commonly used UV absorbers were tested: Octinoxate (EHM), Diethylaminohydroxybenzoyl hexyl benzoate (DHHB), and Ensulizole (PBSA). The final parameters were as follows: porcine ear skin was chosen for the membrane; the temperature of the receptor fluid was 37 °C; a PBS solution with 50% ethanol was chosen for the receptor fluid; and the dose of the test substance was 3 g. The improved IVPT method will help to accurately quantify the in vitro permeation of difficult-to-permeate components. In addition, the method can also be applied to evaluate the permeability of UV absorbers under different formulation conditions, which will help to address the difficulties related to the safety and application of sunscreen products.