[Comparison of various topical sun protection formulations, based on cosmetic vs medical device status, using in vitro methods to assess their efficacy, photo-stability and water resistance]. / Comparaison de produits de protection solaire ayant un statut de cosmétique ou de dispositif médical par détermination de leur efficacité, de leur photo-stabilité et de leur résistance à l'eau grâce à une méthode in vitro.

ABSTRACT

BACKGROUND: Within the European Union, sun protection products have long been considered cosmetics whereas in other parts of the world, such as the United States, they are considered as medicinal products. In France, sun protection products with medical device status have recently appeared. Our aim was to compare medical and cosmetic sun protection products. MATERIALS AND METHODS: We subjected 4 sun protection products to in vitro testing in order to determine their efficacy in the UVB and UVA ranges, as well as their photo-stability and water resistance. We tested two cosmetic products (Dépiwhite S Soin photoprotecteur(®) SPF 50+ and Urgo cicatrices(®) SPF 30) and two class I medical devices (MD) (Actinica lotion(®) and Kelocote UV(®) Gel for scars). The main in vitro method used involved measuring the transmittance of a sample of each product applied to a dish containing poly(methyl methacrylate) using a spectrophotometer with integrating spheres. This method enabled us to determine the SPF of the various products as well as their photo-stability and degree of water resistance. RESULTS: Regarding efficacy, three of the four test products met the European recommendations governing sun protection products, i.e. a ratio between UVB and UVA protection of 3 or less, and a critical wavelength (λc) of 370 nm or higher. Actinica lotion(®) was the more effective of the two medical devices tested, and was also the most photo-stable, at least within the UVB range. All four products tested were water-resistant. DISCUSSION: The products tested, while having different status and different claims, exhibited equivalent filtration properties under the study conditions.