Photostability of sunscreens

• Published in: Journal of photochemistry and photobiology. C, Photochemistry reviews Vol. 13; no. 1; pp. 91 - 110
• Main Authors: Kockler, Jutta, Oelgemöller, Michael, Robertson, Sherryl, Glass, Beverley D.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2012
• Subjects: Chemical UV-filters; Photostability; Physical UV-filters; Sunscreens; UV-protection; UV-protection; Physical UV-filters; Sunscreens; Photostability; Chemical UV-filters
• ISSN: 1389-5567; 1873-2739
• DOI: 10.1016/j.jphotochemrev.2011.12.001

► A comprehensive review of the photostability of physical and chemical UV-filters. ► The major photoreactions of these UV-filters individually and in combination. ► The impact on their photostability when used in combination (broad spectrum). ► The effect of the formulation, antioxidants and excipients on photostability. ► The importance of photostability testing for sunscreens, currently not mandatory. Sunscreens were originally designed to include mainly UVB-filters. Because of the deeper penetration of UVA light, causing photoaging and DNA damage, there has been a shift towards broad spectrum sunscreens. These broad spectrum sunscreens now include both UVA- and UVB-filters and other ingredients which possess antioxidant activity. Although sunscreens are regulated in most countries, photostability testing is not mandatory. Because of the ability of sunscreen ingredients to absorb UV-light and the complexity of most of these formulations, which may include more than one UV-filter, antioxidants and other formulation excipients, it is important that their photostability in combination is determined.