Evaluation of Irritation That Could be Caused by Two Facial Gels Applied to Opposite Sides of the Face.

At the Baseline Visit, following satisfaction of entry criteria and screening procedures, all subjects will be applying two products on their faces, each on half face. The side of face receiving each product is randomly assigned. One group will use tretinoin facial gel on the left side and adapalene facial gel on the right side of the face daily for two consecutive weeks after washing with study-supplied facial wash. The other group will use the same products, but on opposite sides of the face for two consecutive weeks after washing with the same study-supplied facial wash.

Subjects will return to the study center every weekday morning for evaluation and for the morning application of both study products. Study personnel will monitor application on the weekdays. There will be a daily clinical evaluation of skin irritation by a blinded dermatologist and by subjects. At baseline and at the end of each week subjects will be photographed and have chromometer readings.

Inclusion criteria

• Healthy volunteers
• Before screening, subjects (or legally authorized representative) must read and sign the IRB approved Informed Consent Form (includes HIPPA and Photo release).
• Subject must have Fitzpatrick Skin Type I, II or III, and judged by the Investigator to have healthy skin.
• Subject's bilateral facial skin must be clear of any confounding irritation, rashes, acne, rosacea, etc. prior to study start.
• Subject must be free of systemic retinoids for at least 2 months.
• Subject must not be using any topical retinoids, systemic antibiotics, nicotinamide or systemic steroids for 1 month prior to study start.
• All other topical medications to face (e.g., steroids, antimicrobials, salicylic acid, and benzoyl peroxide) and cosmetics containing retinols, AHA's and bleaching agents such as hydroquinone are to be discontinued at least 2 weeks prior to study initiation.
• Subjects will not apply any emollients and cosmetics to the facial area 24 hours prior to study initiation.
• Subject must not be planning to become pregnant or nursing before entering the study and during the study period. In addition if using birth control pills, subject must be stabilized for at least 2 months. If subject is of child bearing potential, subject must be using approved method of birth control. Approved methods are birth control pills, implants, patches or spermicide with condoms.

Exclusion criteria

• Subjects who are pregnant or nursing.
• Subjects who have a grade 1 or more for facial erythema.
• Subjects who exhibit any skin condition (i.e., atopic dermatitis, seborrheic dermatitis, and psoriasis) or disease that may require concurrent therapy or may confound the evaluation of drug safety or efficacy.
• Subjects who have a history of hypersensitivity to any of the formulation components listed in Appendix 1.
• Subjects who have received any experimental drug or used any experimental device 30 days prior to initiation of study therapy.
• Subjects who have excessive facial hair that may obstruct or hinder the evaluation of any reactions.
• Subjects who use any known photosensitizing agents.
• Subjects who presently have skin cancer or actinic keratosis on the face.