Enhancing Photoprotection: Assessing Visible Light Photoprotection in Tinted Inorganic Sunscreens

ABSTRACT Background Visible light (VL, 400–700 nm) and long wavelength UVA1 (VL + UVA1, 370–700 nm) have been reported to cause erythema in light skin phototypes, Fitzpatrick skin types I‐III (FST I–III), and to exacerbate pigmentary dermatologic conditions (e.g., melasma, hyperpigmentation, post‐inflammatory hyperpigmentation) in individuals with dark skin phototypes (FST IV–VI). Until recently, limited options existed for photoprotection against VL + UVA1, including tinted formulations containing iron oxides (Fe 2 O 3 ) or pigmentary titanium dioxide (TiO 2 ), as well as antioxidant‐enriched sunscreen systems. Zinc oxide (ZnO) and TiO 2 are often utilized in the development of mineral‐based (inorganic) sunscreens as the active ingredients to protect against broad spectrum Ultraviolet (UV) radiation via their absorption properties. However, some of these products often leave a white cast, particularly on dark skin, making these products unfavorable, altering skin tone appearance leading to concerns for sunscreen compliance. Tinted sunscreens (Fe 2 O 3 ) are designed to enhance cosmetic elegance and improve compliance across diverse skin tones. This study aims to evaluate the photoprotection properties of a novel Zn‐based inorganic tinted sunscreen enriched with five antioxidants (5 AOX) against VL + UVA1 induced biologic effects (hyperpigmentation and erythema). Method Twelve healthy adult subjects with FST IV‐VI were enrolled and the effectiveness of the new Zn/Fe 2 O 3 /5 AOX sunscreen, compared to several commercially available tinted and non‐tinted mineral sunscreens, was evaluated. The erythema and pigmentation assessments were performed by diffused reflectance spectroscopy (DRS), polarized photography, and investigator global scoring immediately, 24 h, and 7 days after irradiation (320 J/cm 2 ). Results DRS results demonstrated that the novel Zn/Fe 2 O 3 /5 AOX effectively reduced immediate erythema and pigmentation as well as delayed pigmentation when compared with formulas containing ZnO only ( p < 0.05). Not all inorganic/Fe 2 O 3 formulas significantly reduced erythema and pigmentation induced by VL + UVA1 when compared with the ZnO only formula. Conclusion These results highlight the enhanced effects of 5 AOX‐enriched tinted mineral sunscreen to be photoprotective against VL + UVA1, with a blendable tint designed for use on skin of all colors aimed at improving patient compliance and overall sunscreen use.