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Published online: 16 May 2017
© Springer International Publishing Switzerland 2017
Abstract Sunscreens have been widely used by the general public for their photoprotective properties, including prevention of photocarcinogenesis and photoaging and management of photodermatoses. It is important to emphasize to consumers the necessity of broad-spectrum protection, with coverage of both ultraviolet A (320-400 nm) and ultraviolet B (290-320 nm) radiation. This review discusses the benefits of sunscreen, different ultraviolet filters, sunscreen regulations and controversies, the importance of broad-spectrum protection, issues of photostability and formulation, and patient education and compliance.
1Introduction
Sunscreens have been widely used by the general public for their photoprotective properties, including prevention of photocarcinogenesis and photoaging and management of photodermatoses. It is important to emphasize to consumers the necessity of broad-spectrum protection with coverage of both ultraviolet (UV) A (UVA; 320-400 nm) and UVB (290-320 nm) radiation.
The basic requirements that sunscreen manufacturers must consider are efficacy, safety, registration, and patent freedom [1]. Ideal sunscreens should have highly efficient filters against both UVB and UVA radiation, be photostable, and be made in formulations that are cosmetically acceptable to the general public. They should have no adverse effect on the environment or on humans. UV filters must be approved by the local regulatory agency for the area in which the products are to be marketed. Obviously, patent infringement must be avoided [1].
2Clinical Benefits of Sunscreens
The harmful effects of solar radiation exposure on human skin are well known. Acute effects of UV radiation include erythema, pigment darkening, vitamin D synthesis, tanning, and photoimmunosuppression. Chronic effects include photoaging and photocarcinogenesis. UV radiation leads to DNA damage. UVB radiation results predominantly in the formation of pyrimidine dimers and 6-4 photoproducts, whereas the predominant effect of UVA radiation is oxidative damage to DNA [2]. The American Cancer Society estimated that about 76,000 new cases of invasive melanoma would be diagnosed in the year 2016 in the USA [3].
The role of sunscreens as effective photoprotective agents in preventing the adverse outcomes of exposure to sunlight has been well studied and documented. A landmark study demonstrated that daily use of sunscreen can prevent the development of melanoma. This longitudinal study conducted in Nambour, QLD, Australia, with 1621 individuals aged 25-75 years assessed the effect...