Gain of Protection Afforded by the Methoxypropylamino Cyclohexenylidene Ethoxyethylcyanoacetate (MCE) UVA1 Filter on Pigmentary and Aging Signs: An Outdoor 4‐Week Randomized, Intra‐Individual Comparative Study in 52 Brazilian Women

ABSTRACT Background Conventional sunscreens shield the skin from ultraviolet (UV) rays up to 370 nm leaving wavelengths between 370 and 400 nm unfiltered despite their potentially harmful biological and clinical effects. Objective The beneficial effects of methoxypropylamino cyclohexenylidene ethoxyethylcyanoacetate (MCE) UVA1 filter were explored at 1% in a SPF50 sunscreen under outdoors summer conditions against pigmentation and aging signs compared against a reference SPF50 without the MCE filter. Materials and Methods A prospective randomized comparative intra‐individual study was conducted in 52 Brazilian women (phototype I–III). A hemiface application was performed for the SPF50 sunscreen with 1% MCE and SPF50 reference without MCE before 1‐h outdoor sunlight exposure, twice daily for 4 weeks. Study endpoint included expert panel grading of pigmentation (3), vascular (1) signs as well as facial skin ageing and assessment of facial skin radiance and skin homogeneity by a naïve panel. Results Significant differences were reported for all facial signs comparing areas protected with SPF50/MCE and SPF50, respectively: upper lip wrinkles, crow's feet wrinkles, upper lip texture, upper lip pigmentation, vascular abnormalities (all p < 0.0001), texture of the mouth contour ( p = 0.001), ptosis of lower face ( p = 0.003), lateral facial pigmentation ( p = 0.005), and whole face pigmentation ( p = 0.01). The evaluations performed by naïve panel showed a significant superiority of the SPF50/MCE product for skin homogeneity ( p = 0.043). Conclusion Overall, this study demonstrates a significant gain of protection with the SPF50 containing 1% MCE in reducing hyperpigmentation, redness and aging signs compared to the same SPF50 sunscreen without MCE, thus supporting the need for an enlarged UVA1 photoprotection.