Photostability of commercial sunscreens upon sunlight exposure

Introduction: The use of sunscreens is recommended to reduce skin damage and prevent skin cancer. However, evidence has shown that sunscreen can undergo degradation processes induced by ultraviolet (UV) radiation which can lead to reduction or loss of photoprotective capacity, generation of free rad...

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Bibliographic Details
Published in:	H.U. revista Vol. 46; pp. 1 - 9
Main Authors:	Prado, Rhaíssa, Bertges, Filipe Soares, Figueiredo, Sônia Aparecida, Fonseca, Maria José Vieira, Tavares, Guilherme Diniz, Vilela, Fernanda Maria
Format:	Journal Article
Language:	English
Published:	Universidade Federal de Juiz de Fora 17-08-2020
Subjects:	Cosmetic Stability Photodegradation Sunscreenig Agents Ultraviolet Filters
Online Access:	Get full text
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Summary:	Introduction: The use of sunscreens is recommended to reduce skin damage and prevent skin cancer. However, evidence has shown that sunscreen can undergo degradation processes induced by ultraviolet (UV) radiation which can lead to reduction or loss of photoprotective capacity, generation of free radicals and toxic intermediates which react with skin structures generating biological damage. Objective: To evaluate the photostability of four sunscreen formulations with Sun Protection Factor (SPF) 30 added by different chemical and physical UV filters. Material and Methods: Each product was exposed to solar radiation from 10 a.m. to 15 p.m. (UV index: 6.0). The areas under the curves (AUC) of the absorbance spectrum of the formulations before and after radiation exposure were used to calculate the ratio between the AUC before and after the solar radiation (AUCI). Results: Only two formulations, which presented the AUCI higher than 0.8, were considered photostable. Despite having the same SPF 30, formulations showed different absorption spectrum in regions of UVA1, UVA2 and UVB and the photostability of the products tested varied considerably. Conclusion: The development of photostable formulations is critical because degradation products of UV filters can act as photo-oxidants. Furthermore, increased exposure to UV radiation due to the reduction of the photoprotective capacity of unstable products increases the risk of burns and skin cancer.
ISSN:	0103-3123 1982-8047
DOI:	10.34019/1982-8047.2020.v46.28819