Evaluation of Allergenicity by HRIPT and Phototest

Clinical Evaluation of the Allergenic Potential of a Cosmetic Product Using the Human Repeat Insult Patch Test (HRIPT) and Phototest

This clinical study will evaluate the dermatological safety and allergenic potential of a cosmetic product. The study will use the Human Repeat Insult Patch Test (HRIPT) and phototest procedures to assess whether the product may cause skin irritation, allergic reactions, photoirritation, or photosensitization after repeated use and exposure to ultraviolet light.

Participants will receive applications of the investigational product under controlled conditions and will undergo dermatological evaluations throughout the study. The results will help determine the product's skin compatibility and safety for consumer use.

This is a single-center, single-blind, non-comparative clinical study designed to evaluate the dermal compatibility and allergenic potential of an investigational cosmetic product using the Human Repeat Insult Patch Test (HRIPT) and phototest procedures.

The HRIPT phase will assess primary dermal irritation, cumulative irritation, and skin sensitization potential through repeated applications of patches containing the investigational product to the participants' backs under maximized conditions. The practical phase lasts six weeks and includes three weeks of product application, two weeks of rest, and one challenge week with product reapplication on a previously untreated skin site.

The phototest phase will assess the photoirritant and photosensitizing potential of the investigational product following controlled exposure to ultraviolet radiation. Product-containing patches will be applied to the skin and, after removal, the test sites will undergo controlled ultraviolet irradiation. The practical phase lasts five weeks and includes induction, rest, and challenge phases.

Dermatological evaluations will be performed according to standardized criteria, including assessments based on the International Contact Dermatitis Research Group (ICDRG) scale, to confirm the absence of clinically significant irritant, allergenic, photoirritant, or photosensitizing reactions.

Inclusion Criteria:

• Male and female participants aged 18 to 70 years.
• Fitzpatrick skin phototypes I, II, III, or IV.
• Intact skin at the application site.
• Willingness to comply with all study procedures and attend scheduled clinic visits for medical assessments, patch applications, and patch readings.
• Ability to understand the study requirements, provide written informed consent, and sign the Informed Consent Form (ICF).

For the phototest procedure, only participants with Fitzpatrick skin phototypes II and III will be eligible.

Exclusion Criteria:

• Pregnant or breastfeeding women, or women at risk of becoming pregnant during the study.
• Use of anti-inflammatory medications within 30 days prior to screening or immunosuppressive medications within 3 months prior to screening.
• Immunosuppression due to medication use or active disease.
• Uncontrolled endocrine disorders.
• Personal history of atopy.
• Intense sun exposure or tanning sessions within 15 days prior to assessment or during the study period.
• Planned intense sun exposure or tanning sessions during the study period.
• Planned sea bathing, swimming pool use, or sauna sessions during the study period.
• Participation in water sports during the study period.
• Dermographism.
• Use of oral or topical vitamin A acid (retinoids) or related derivatives within 1 week prior to study initiation.
• Aesthetic and/or dermatological body treatments within 3 weeks prior to screening.
• Scheduled vaccination during the study period or within 3 weeks prior to screening.
• History of sensitization, irritation, or photosensitization to topical products.
• Active local or generalized skin diseases that may interfere with study assessments.
• Skin hyperreactivity.
• Initiation of new medications during the study period.
• Previous participation in studies involving the same investigational product.
• Congenital or acquired immunodeficiency.
• Relevant medical history or current evidence of alcohol or substance abuse.
• Known or suspected intolerance to any ingredient contained in the investigational or comparator products.
• History of poor compliance or unwillingness to comply with the study protocol.
• Employees of the study site, sponsor, or their immediate family members directly involved in the study.
• Any other condition that, in the investigator's opinion, may interfere with study participation or justify exclusion from the study.

Additional Exclusion Criteria for the Phototest:

• History of diseases aggravated or triggered by ultraviolet radiation.
• Use of photosensitizing medications.
• History or current presence of photodermatoses.
• Personal or family history of skin cancer.
• Presence of precancerous skin lesions, including melanocytic nevi or actinic keratoses, that may interfere with study assessments.