A randomized, double-blind, split-face study comparing the efficacy and tolerability of three retinol-based products vs. three tretinoin-based products in subjects with moderate to severe facial photodamage.

Retinol, has been shown to improve the appearance of photodamaged skin when applied topically, and is generally considered to be approximately ten times less potent than tretinoin. To assess this theory, three cosmetic formulations containing 0.25%, 0.5%, and 1.0% retinol were developed to correspond to the three commonly prescribed concentrations of tretinoin (0.025%, 0.05%, and 0.1%). A randomized, double-blind, split-face comparison study was conducted to compare the three concentrations retinol (Ret) including 0.25%, 0.5%, and 1.0%, against the respective three strengths of tretinoin (Tret) 0.025%, 0.05%, and 0.1% in subjects with moderate to severe facial photodamage. Subjects were randomized into three groups: Group 1 (Ret 0.25% vs. Tret 0.025%); Group 2 (Ret 0.5% vs. Tret 0.05%); and Group 3 (Ret 1.0% vs. Tret 0.1%). Within each group, subjects were randomized to apply Ret on one half of the face (left or right) and Tret on the other facial side, for a duration of twelve weeks. Clinical evaluations for efficacy and tolerability, as well as standardized digital photographs were conducted at baseline and at weeks 4, 8, and 12. Sixty-five subjects completed the twelve-week study (Group 1: n=24, Group 2: n=20, and Group 3: n=21). At week 12 in all treatment groups, both Ret and Tret produced statistically significant improvements from baseline in all efficacy parameters, including overall photodamage, fine lines/wrinkles, coarse lines/wrinkles, skin tone brightness, mottled pigmentation, and tactile roughness (all P<0.001). There were no significant differences in efficacy between Ret and Tret in these efficacy parameters. Results from this comparison study suggest that this sustained-release retinol complex containing multiple agents for optimal irritation control provides comparable improvements to tretinoin in the appearance of photodamage.