Evaluation of the Photoprotection Efficacy with Sunscreen Formulas Under Visible Light Exposure

The sunscreens usually used as photoprotectors are known to protect in the UV domain (UVB and UVA). However, until recently visible light (400-700 nm) was considered as devoid of any photobiological effects on cutaneous tissue. Over the last two decades, with the development of photodynamic therapies and various dermatological treatments using visible laser light, several studies have reconsidered the cutaneous effect of visible light on the skin, in particular the induction of pigmentation.

The aim of this study was to assess the ability of sunscreens with a protective efficacy in the UV domain to prevent the pigmentation induced by Visible Light.

Inclusion criteria

• Healthy subject of both sexes aged 18 - 50 years old, having a phototype IIIb, IV or V according to Fitzpatrick classification (4),
• Subject with an ITA° (Individual Typologic Angle calculated value) between -20° and 28° at the screening visit,
• Healthy subject based on physical examination and compatibility of medical history with the study content,
• Woman of childbearing potential using adequate contraception (oral contraception, intra-uterine devices, contraceptive implants or vaginal rings, tubal sections or ligations, condoms) for at least 1 month prior to first visit and agreeing to continue adequate contraception during the entire duration of the study,
• Woman of non-childbearing potential (menopausal with one year without bleeding, hysterectomy, bilateral ovariectomy),
• Subject having signed a written informed consent form and dated before any study procedure begins.
• Subject willing to actively cooperate during the study duration and willing to complete the study,
• Subject affiliated to the social security system (according to the French Law 2004-806 and its implementing decree n°2006-477 of 26 April 2006).

Exclusion criteria

• Female who was pregnant or breast feeding or planning a pregnancy during the study,
• Subject having an underlying known disease, or surgical, physical, or medical condition that, in the opinion of the Investigator may have interfered with the interpretation of the clinical trial results such as:

• History of recurrent dermatologic conditions (e.g., psoriasis, eczema, urticaria…) or suspicion/history of allergy to cosmetics,
• Any systemic or local disease pathology
• Skin abnormality (scars, excessive hair, tattoos…) at the level of the test zones (middle part of the back),
• Subject who had been overexposed to natural (sun) or artificial ultraviolet (tanning lamps) in the last month prior the first visit or who planned a such exposure during the study;
• Subject having history or presenting pathologies induced or aggravated by sun exposure or having abnormal reactions to the sun (ex : photosensitive dermatitis, polymorphic light eruption, solar urticaria, systemic erythematous lupus, dermatomyositis),
• Subject having taken a systemic treatment more than 5 days in the month preceding the inclusion (steroids, nonsteroidal anti-inflammatory drugs such as aspirin, antihistamine, insulin, hypertensors, antibiotics such as quinolones, tetracyclins, thiazids, fluoroquinolons and and photosensitising treatment) or any treatment able to induce abnormal response to UV or visible light (vitamin A derivatives, psoralen, aminolevulinic acid..) or having planned to take these treatments during the study,
• Subject having applied a local treatment on the back for more than 2 days during the 2 weeks preceding inclusion (steroids, non-steroidal anti-inflammatories, antihistamines, antibiotics) and all other cosmetic products in the previous 24 hours,
• Subject having antecedents of clinically significant allergy, particularly to study product components,
• Subject requiring enhanced protection (deprived of liberty, minors, under guardianship),
• Subject being in a situation which, according to the Investigator, could have interfered with an optimal participation in the study,
• Subject currently participating or having participated in another clinical trial during the month preceding inclusion,
• Subject under care of guardian or legal guardianship or subject hospitalized in a medical or social establishment for any reason,
• Subject unable to communicate efficiently with the Investigator or being unable to follow the study requirements