Commonly used UV filter toxicity on biological functions: review of last decade studies

Abstract

SynopsisSunscreens provide broad-spectrum UV skin protection and contain more often UV filter combinations. Their efficacy reducing skin photo carcinogenesis and photo ageing is widely documented. However, there are many concerns about UV filter safety. Organic UV filters were the first targeted by scientist concerns, as they were showed to trigger skin allergic reactions. Inorganic UV filters were then at the heart of scientist debate especially because of their nanometric size. Over the last years, many studies have been published tending to highlight that organic as well as inorganic UV filters could lead to variable side effects after sunscreen application. However, these studies are still very controversial due to different experimental conditions and models. This review reveals that complementary studies using standardized methods are mandatory before ascertaining that UV filters threaten human health. R esum eLes produits solaires destin es a prot eger la peau contre les irradiations UV contiennent le plus souvent des combinaisons de filtres UV. Ces filtres permettent de r eduire le vieillissement pr ematur e de la peau ainsi que la survenue de cancer cutan e. Cependant, la nocivit e des filtres UV est toujours un sujet de controverse. Ainsi, des r eactions allergiques li ees a l'utilisation de produits solaires contenant des filtres UV organiques ont et e rapport ees dans la litt erature. R ecemment, l'utilisation de filtres UV min eraux a l' echelle nanom etrique, dispers es dans les produits destin es a la protection solaire a fait l'objet de travaux scientifiques visant a etablir le niveau de p en etration cutan ee. Ces derni eres ann ees, de nombreuses etudes ont et e publi ees tendant a montrer que les filtres UV organiques et inorganiques peuvent entrainer divers effets ind esirables. Mais, ces diverses etudes restent tr es controvers ees notamment a cause des diff erences dans les conditions exp erimentales et les mod eles utilis es. Cette revue r ev ele que des etudes compl ementaires utilisant des m ethodes standardis ees sont n ecessaires pour confirmer ou infirmer que les filtres UV pr esentent un risque sanitaire.

Cutaneous Permeation and Penetration of Sunscreens: Formulation Strategies and In Vitro Methods

“…It is not infrequent to see different types of molecules contemporaneously present in commercially available formulations, used in combination because none of them is individually able to provide broad spectrum UVA-UVB protection [8][9][10]. The active molecules could be classified as either "chemical" or "physical" based on their mechanism of action: In chemical sunscreens, the active ingredient is an organic compound, with aromatic structure, that works by absorbing UV radiation and dissipating the energy as heat or light; in physical sunscreens, the active ingredient is an inorganic compound that acts by physically reflecting or scattering the UV radiation (e.g., minerals particles such as zinc oxide and titanium dioxide) [1].…”

Standardization of an in vitro Model for Evaluating the Bioavailability of Topically Applied Compounds on Damaged Skin: Application to Sunscreen Analysis

“…Likewise, sunscreens are often applied to skin which is already physiologically damaged or dried out, sunburnt by UV irradiation, or affected by other environmental factors such as wind, salt, and sand [3,4]. Therefore, understanding and measuring the absorption of compounds using well-characterized models that mimic damaged skin is important in assessing the safety of pharmaceuticals and cosmetics for topical use.…”

Morphological impact of zinc oxide particles on the antibacterial activity and human epithelia toxicity

“…The food supplements industry offers ZnO based products, because Zn is an essential micronutrient, serving important roles in human and animal growth, development and well-being [4,6]. Due to its excellent UV absorption and reflective abilities, nano-sized ZnO is also found in personal care products in cosmetics and sunscreens [7,8]. Furthermore, ZnO particles have the potential to become a next generation biocide or disinfecting agent, due to their stability and lower probability of developing resistances in comparison to their organic-based counterparts [9][10][11].…”