Current problems in the use of organic UV filters to protect skin from excessive sun exposure

Abstract

The evidences of the harmful effects of skin exposure to excessive UltraViolet (UV) radiation, primarily on the development of skin cancer, have increased over the last decade. Therefore, national and international health authorities have encouraged the public to take protective sunscreens, and respectively also everyday cosmetics containing UV filters. In these products, a mixture of the UV filters, including both inorganic and organic nature, has been shown to be more effective than the individual UV filter. However, currently there are concerns about the safety and actual effectiveness of some UV filters; especially about certain UV-absorbing compounds (organic UV filters). Three cardinal problems are the most questionable. First, that certain UV filters are absorbed through the skin resulting in systemic exposure with unknown consequences. Second, that certain UV filters show the potential to be adversely endocrine disruptors. Third, that certain UV filters are partially degraded by UV radiation, what making them photounstable and unable to fulfil their basic protective function. The purpose of this article is to discuss these problems.

Development of Nanostructured Lipid Carriers (NLCs) Using Pumpkin and Kenaf Seed Oils with Potential Photoprotective and Antioxidative Properties

“…Higher SPF generally requires higher percentages of UV filters or combination of both organic and inorganic compounds in the products. However, synthetic UV filters used in sunscreens could be absorbed through the skin resulting in systemic exposure with unknown consequences and potential endocrine disruption . This is because the UV filters may be degraded by UV radiation, making them photounstable and unable to fulfill their principal functions .…”

“…However, synthetic UV filters used in sunscreens could be absorbed through the skin resulting in systemic exposure with unknown consequences and potential endocrine disruption . This is because the UV filters may be degraded by UV radiation, making them photounstable and unable to fulfill their principal functions . Furthermore, the lipophilic nature of many UV filters may also cause bioaccumulation in humans and animals .…”

Synthesis and photoprotective properties of new salicylic and vanillic acid derivatives

“…2,6,9 Photoprotective agents used in sunscreens can be classified into organic (chemical) and inorganic (physical) on the basis of their mechanism of action. 12 Organic agents absorb UV radiation with excitation to a higher energy state and returning to the stable state release insignificant amount of heat or emit fluorescent radiation. 2,12,13 They include p-aminobenzoic acid (PABA) and its derivatives, cinnamates, salicylates, camphors, benzophenones, among others.…”

“…12 Organic agents absorb UV radiation with excitation to a higher energy state and returning to the stable state release insignificant amount of heat or emit fluorescent radiation. 2,12,13 They include p-aminobenzoic acid (PABA) and its derivatives, cinnamates, salicylates, camphors, benzophenones, among others. 1,2,6,10,[12][13][14] Inorganic agents, primarily titanium dioxide and zinc oxide, reflect and scatter UV radiation increasing the optical pathway of the photons in the sunscreen formulation leading to higher efficiency of the organic photoprotective agents.…”

“…1,2,6,10,[12][13][14] Inorganic agents, primarily titanium dioxide and zinc oxide, reflect and scatter UV radiation increasing the optical pathway of the photons in the sunscreen formulation leading to higher efficiency of the organic photoprotective agents. 2,12,13 In order to provide a high level of sun protection against a wide range of the UV spectrum multiple compounds are usually incorporated into sunscreening cosmetics -no single photoprotective agent can provide a high sun protection factor 6,13 at the level required by consumers and regulatory agencies, e.g. FDA in the USA or the Commission of the European Communities in the EU.…”