New Nanocapsules with High Loading of UV-Filters

UV radiation is the main malefactor of several types of skin cancer and the visible signs of photoageing (1,2). Mainly ultraviolet A (UVA) radiation (320 - 400 nm), able to penetrate into the deeper skin layers, is responsible for the generation of free radicals and arising oxidative stress. The importance of adequate UVA protection has therefore become a major goal in sun care as well as in skin care. A huge variety of organic sun filters are on the market. Both UVA and UVB filters are mainly oil soluble. Therefore they can not be used in innovative oil-free sun care formulations like sprays or gels. Special products have been developed to get a »water-soluble« UVA filter by different encapsulation technologies (Hybrid from Sunjin (3) or Eusolex UV-Pearls from Merck (4,5)). In both cases the UVA filter Avobenzone was encapsulated together with a UVB filter to increase the photostability of Avobenzone. The total filter concentration in both preparations is approximately 40%. This encapsulation into the particles (2 - 7 μm for Hybrid and 1 μm for the Pearls) separates the UVA filter from other components coming out from the formulation and enhances the safety of the formulation.