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

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.