Antioxidants and cactus extract enhances the sun protection factor of octocrylene and oxybenzone solution

Abstract

Ultraviolet (UV) filters such as octocrylene and oxybenzone in topical photoprotection products work effectively in absorbing UV radiation, thus minimizing sun damage to the skin. Antioxidants are incorporated into sunscreen products to enhance the photoprotection ability of the products. However, the effectiveness of the antioxidants on the sun protection factor (SPF) of UV filters is not well established. Hence in this study, the effect of caffeine, nicotinamide, β-carotene, α-tocopherol, and cactus extract on the SPF of octocrylene and oxybenzone were investigated. The UV absorbance of octocrylene (5 µg/mL) and oxybenzone (20 µg/mL) in 95% ethanol, with different concentrations of the antioxidants (0.1–100 µg/mL) and cactus extract were measured from 290-320nm. The UV absorbance values were converted to SPF values by the Mansur equation. Statistical analysis was performed by ANOVA test and Post Hoc test (Dundett T3 test) with a significance level of p<0.05 using SPSS software. The antioxidants and cactus extract were found to significantly increase the SPF of octocrylene and oxybenzone solutions in a concentration-dependent manner. Out of the antioxidants tested, β-carotene and α-tocopherol were the most effective antioxidants to increase the SPF of octocrylene solution and oxybenzone solutions, respectively. The results supported that it is beneficial to incorporate antioxidants and cactus extract into the formulation of topical photoprotection products.