Evaluation of the anti-wrinkle effect of an ascorbic acid-loaded dissolving microneedle patch via a double-blind, placebo-controlled clinical study

Objective: Although an ascorbic acid-loaded dissolving microneedle patch has been developed to improve anti-wrinkle effects, an efficacy evaluation with a control group has not yet been performed. In this study, the anti-wrinkle effect of an ascorbic acid-loaded dissolving microneedle patch was evaluated in a double-blind clinical study with a control group. In addition, a cumulative skin irritation and sensitization potential of the ascorbic acid-loaded dissolving microneedle patch was performed. Methods: Twenty-three subjects were selected for anti-wrinkle effect evaluation in a double-blind clinical study. Subjects were divided into two groups. Group I subjects applied an ascorbic acid-loaded dissolving microneedle patch on a crow's feet area on the left side of the face and a control sample on a crow's feet area on the right side of the face every 4 days. Group II subjects placed the same patches on opposite sides of the face. Global Photodamage Score and skin replica analysis were conducted by visual inspection and skin visiometer, respectively. A skin irritation and sensitization assessment was performed on 51 subjects using the modified Shelanski & Shelanski procedure. Cumulative skin irritation potential and skin sensitization of the ascorbic acid-loaded dissolving microneedle patch and control sample were evaluated. Results: Skin treated with the ascorbic acid-loaded dissolving microneedle patch showed a statistically significant improvement in both the Global Photodamage Score and visiometer R values (P < 0.05) compared with the control sample. The R2 value (maximum roughness), in particular, showed a highly significant improvement (P < 0.01). The skin irritation and sensitization assessment demonstrated that the ascorbic acid-loaded dissolving microneedle patch did not induce any cumulative skin irritation potential or skin sensitization. Conclusions: An ascorbic acid-loaded dissolving microneedle patch produced a significant anti-wrinkle effect without skin irritation and sensitization problems. This cosmetic dissolving microneedle patch can be used efficiently in the anti-wrinkle cosmetic field with patient convenience.