Subject(s)
Sunscreening Agents , Ultraviolet Rays , Humans , Benzopyrans , Indoles , Skin , Ultraviolet Rays/adverse effectsABSTRACT
BACKGROUND: UVA1 rays (340-400 nm) contribute to carcinogenesis, immunosuppression, hyperpigmentation, and aging. Current sunscreen formulas lack sufficient absorption in the 370-400 nm wavelengths range. Recently, a new UVA1 filter, Methoxypropylamino Cyclohexenylidene Ethoxyethylcyanoacetate (MCE) exhibiting a peak of absorption at 385 nm, was approved by the Scientific Committee on Consumer Safety for use in sunscreen products. These studies evaluated, in a three-dimensional skin model and in vivo, the protection afforded by state-of-the-art sunscreen formulations enriched with MCE. TRIAL DESIGN: This study is a monocentric, double-blinded, randomized, and comparative trial. This study is registered at ClinicalTrials.gov with the identification number NCT04865094. METHODS: The efficacy of sunscreens with MCE was compared with that of reference formulas. In a three-dimensional skin model, histology, protein, and gene expression were analyzed. In the clinical trial, pigmentation was analyzed in 19 volunteers using colorimetric measurements and visual scoring. RESULTS: MCE addition in reference formulas enlarged the profile of absorption up to 400 nm; reduced UVA1-induced dermal and epidermal alterations at cellular, biochemical, and molecular levels; and decreased UVA1-induced pigmentation. CONCLUSIONS: Addition of MCE absorber in sunscreen formulations leads to full coverage of UV spectrum and improved UVA1 photoprotection. The data support benefits in the long term on sun-induced consequences, especially those related to public health care issues.
Subject(s)
Skin/drug effects , Sunburn/prevention & control , Sunscreening Agents/administration & dosage , Ultraviolet Rays/adverse effects , Administration, Cutaneous , Adult , Culture Techniques , Cytokines/metabolism , Humans , Inflammation Mediators/metabolism , Matrix Metalloproteinases/metabolism , Proof of Concept Study , Skin/metabolism , Skin/pathology , Sunburn/metabolism , Sunburn/pathology , Young AdultABSTRACT
INTRODUCTION: It is now recognized that to adequately protect skin from sun damage, sunscreens require a photostable combination of ultraviolet (UV) filters with a suitable level of UVA protection. The total amount of UV filters should be as low as possible to avoid adverse skin reactions, potential environmental impact, and to ensure acceptable texture for better application and usage. METHODS: A synergistic combination of UV filters was selected to obtain a high sun protection factor (SPF) and UVA protection factor (UVA-PF). An oily vehicle was then added to the formula to improve the solubility and the photostability of the lipophilic UV filters. RESULTS: The combination of filters, i.e., terephthalylidene dicamphor sulfonic acid (TDSA), bis-ethylhexyloxyphenol methoxyphenyl triazin (BEMT), and butyl methoxy dibenzoyl methane (BMDM), obtained an elevated SPF as well as a high UVA-PF. Isopropyl lauroyl sarcosinate (ILS), a derivative of a natural amino acid (sarcosine, also known as N-methylglycine) was introduced in this formulation in order to dissolve the oil-soluble UV absorbers and to photostabilize BMDM. The new sunscreen formulation obtained with this combination is photostable and contains a reduced amount of UV filters compared to other sunscreens with the same level of efficacy. CONCLUSION: This report described the steps resulting in the formulation of a new combination of UV filters in an oily emollient, which presents a high UVA-PF (UVA-PF = 38) and a SPF 50+, is photostable, and offers good protection against UV-induced biological damage.
