Development of Organic UV Filters and Their Effective Usage

Abstract

Organic UV filters utilized in sunscreen have been developed targeting more efficient UV protection in their history. Sunscreens in the early days focused on prevention of sunburn mainly caused by UVB; thus organic UVB filters became the first commercial examples of synthetic organic UV filters. Among them, Ethylhexyl methoxycinnamate (EHMC) became most popular due to balanced performance and handling advantages. In the 1970s, Butyl methoxydibenzoylmethane (BMBM) was commercialized as the first organic UVA filter, reflecting increased awareness of photoaging mainly caused by UVA. Meanwhile, however, the photostability of EHMC and BMBM had been discussed more often. Therefore, photostability is considered an important characteristic in the molecular design of new-generation organic UV filters. In addition to conventional oil/water soluble organic UV filters, aqueous dispersion of particulate organic UV filers became available. Due to aqueous dispersion, these particulate organic UV fitters provide water phase protection, which efficiently prevent UV light from passing through holes originating from the water phase. These particulate organic UV filters can also provide so-called “Triple Action” efficient UV protection through the combination of absorption, reflection and multi-scattering. In addition to properties and effects, modern UV filters must satisfy broad needs of product safety and regulation from the viewpoint of sustainability. An overview of recent regulatory updates related to organic UV filters is briefly summarized here.