4-n-butylresorcinol dissolving microneedle patch for skin depigmentation: a randomized, double-blind, placebo-controlled trial

Background: For effective skin depigmentation, the skin depigmentation agent must be delivered to melanocytes, where melanin is synthesized. Although dissolving microneedle (DMN) is one of the best transdermal drug delivery systems to deliver the active compound, no clinical trial has been conducted in terms of safety and efficacy. Objectives: To assess the clinical efficacy and safety of a DMN patch that contained 4-n-butylresorcinol, a skin depigmentation agent. Methods: In the safety assessment, 31 subjects were selected for primary skin irritation test using Frosch & Kligman's method and 50 women for the cumulative irritation test and sensitization potential test using a modification of the Shelanski–Shelanski method. In the efficacy assessment, the 4-n-butylresorcinol DMN patch was compared with a control (DMN without 4-n-butylresorcinol) in our double-blind, placebo-controlled study with 45 subjects by measuring two parameters, the melanin index and individual typology angle value, during 8 weeks of administration. Results: The 4-n-butylresorcinol DMN patch was shown to be safe based on the results of the safety assessment and was more than two times effective than the control patch. Conclusion: The 4-n-butylresorcinol DMN patch was effective and safe for skin depigmentation through targeting melanocytes and could be a useful functional cosmetic product.