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Background
Chronic sun exposure induces skin damage leading to skin ageing and skin colour heterogeneity with hyperpigmented spots. In this process ultra violet A (UVA) rays highly contribute, especially long‐UVA (UVA1) supporting the need for an efficient photoprotection over the whole UV spectrum. A new UVA1 filter, methoxypropylamino cyclohexenylidene ethoxyethylcyanoacetate (MCE), with a pic of absorption at 385 nm, has been recently approved for use in sunscreen products.
Objective
Three randomised clinical studies were performed to evaluate the additional photoprotection afforded by a sunscreen formula containing MCE compared to state‐of‐the‐art sunscreen lacking absorption in the longest UVA1 wavelengths. Two studies were performed on European volunteers with UV‐controlled (UVA1, ultra violet B (UVB) + UVA) exposures and one on Indian volunteers under real sun exposures.
Methods
Three intraindividual trials (two randomised UV‐controlled and one real sun) were conducted on a total of 62 healthy subjects with Fitzpatrick III–IV and individual typology angle (ITA°) values between −18° and 35°. The MCE at 2% was formulated in a state‐of‐the‐art sun protection factor 30 sunscreen reference allowing to enlarge the absorption profile up to 400 nm. UV‐induced pigmentation was assessed by colorimetric measures and visual scoring at different time points after a single exposure to UVA1 (Study 1) or repeated exposures to daily UV radiation comprising both UVB and UVA (Study 2) or under real sun (Study 3).
Results
Whatever the study exposure condition (UVA1, UVB + UVA, real sun), the level of pigmentation was increased as attested by colorimetric parameters (decreased luminance L* and ITA° values) and visual scorings. In the three studies, the comparison showed higher prevention of hyperpigmentation with the sunscreen enlarged in the longest UVA1 wavelengths with MCE compared to the state‐of‐the‐art sunscreen. No side effects were reported.
Conclusions
MCE is a valuable UVA1 filter to improve photoprotection over the entire UV spectrum in state‐of‐the‐art sunscreens and limits the impact of UVA1 rays.
The practice of brightening and unifying skin tone dates back over many years in different communities around the world, typically by people with skin phototypes IV-VI. Even skin tone and skin homogeneity are highly desired beauty attributes, influencing consumer demand for skin radiance cosmetic products or drugs. 1 Several agents with different mechanisms of action are commonly misused, 2,3 such as topical steroids that bleach the skin and reduce its thickness, [4][5][6] and hydroquinone that reduces melanosome formation leading to melanocyte necrosis 3 and is now considered as potentially carcinogenic. 2,7 To promote inclusiveness and satisfy the consumer, the challenge remains to develop safe technologies providing perceivable benefits in skin tone evenness, while respecting the individual
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