Nanosized and Nanoencapsulated Sunscreens

Abstract

Abstract. Nanotechnology represents an important complement to traditional chromophore-based UV filters. Nanosized metal oxides are widely used due to their broad protection spectrum and reduced skin irritation. These particles are already present in most commercial sunscreen lotions even though their photoreactivity has been highlighted as a potential cause of cytotoxic effects in human skin cells (e.g. fibroblasts, epithelial cells). However, this cytotoxicity is not likely to represent a significant health risk to consumers as several skin penetration assays have shown that the photoreactive particles penetrate at most to the stratum spinosum of the epidermis. Nanoencapsulation of traditional organic UV filters is a more recent approach to improve skin retention, photostability and the UV blocking ability of the free molecules. All of these improvements have been confirmed with different scientific assays for different particles, especially polymeric nanocapsules and solid lipid nanoparticles. These technological advantages offered by nanometric particles for sun protection formulations have made them commercially important. In inventories from non-governmental organizations there are approximately 30 commercial sunscreen products listed as containing nanoparticles.

Novas Estratégias Em Fotoproteção

“…A nanoencapsulação dos filtros UV orgânicos tradicionais é a mais recente tecnologia para melhorar a retenção na pele, fotoestabilidade e aumentar o bloqueio UV por parte das moléculas livres. A diminuição da penetração dos filtros orgânicos é promovida pela nanoencapsulação e como resultado ocorre a formação de um filme na superfície da pele (DETONI et al, 2011;Deltreggia, et al, 2019). Dessa forma os agentes protetores ficam nas nanocápsulas e são liberados gradativamente, melhorando sua eficácia, reduzindo o risco de alergia, aumentando a concentração do produto disponível dentro da emulsão.…”

Vesicular systems for dermal and transdermal drug delivery

“…Being isolated from potential reactive species in their environment, their photostability and their ability to block UV were also optimized. 61 Other applications for nanocapsules include disinfection with the encapsulation of chlorhexidine and the local delivery of indomethacin or minoxidil. 62 …”

Nanoparticle platforms for dermal antiaging technologies: Insights in cellular and molecular mechanisms

“…Molecular sunscreens like benzophenone-3 (BZ-3) penetrate into skin and induces symptoms of photoaging, photoallergies, phototoxic reactions, and skin irritation. Studies have shown that nanoencapsulation of such traditional UV filters and antipollution agents in organic nanocarriers, potentially help to improve their skin retention, stability, UV blocking action, and anti-pollutant action (Detoni et al, 2011). For instance, the encapsulation of BZ-3 inside PCL and SLNs nanocarriers cause a significant improvement in the stability and sunburn protective action of BZ-3 when compared to BZ-3 alone.…”