Botulinum Toxin-loaded Detachable Dissolvable Microneedles for Primary Axillary Hyperhidrosis: A Pilot Study on Efficacy and Safety.

Objective: Botulinum toxin injection is a well-established treatment for primary hyperhidrosis. The botulinum toxin-loaded detachable dissolvable microneedles (BoNT-MNs) were developed in a result of disadvantages of the intradermal procedure. This pilot study aims to evaluate the efficacy and safety of BoNT-MNs.

Methods: This within-subject study included ten adults (N=10; 100% female) with mild primary axillary hyperhidrosis. BoNT-MNs patches were prepared and each microneedle patch contained 15 units of onabotulinum toxin. BoNT-MNs and placebo patches were randomly applied to different sides of axilla. Iodine-starch test, dermatologists' and patients' satisfaction scores were assessed at baseline and Weeks 1, 2, 3, 4, 8, 12, 16, 20, and 24.

Results: All ten female subjects completed the trial. Notably, on the BoNT-MNs side, iodine starch scores exhibited an onset at Week 2, with a 57.14-percent reduction at Week 12, returning to baseline after Week 20. Dermatologists' and patients' satisfaction scores were consistently superior to the placebo side from Week 2 and Week 1, respectively, until Week 16, with statistical significance (p<0.05) observed at Week 12 and Week 2.

Limitations: This study involved a limited number of female participants and administered a single, small dosage of botulinum toxin in the BoNT-MNs.

Conclusions: Botulinum toxin-loaded detachable dissolvable microneedles patches offer a safe and effective method for reducing axillary sweating.

Clinical trial: This study was approved by the Institutional Review Board of Faculty of Medicine, Chulalongkorn University with IRB number 567/63, and registered in the Thai Clinical Trials Registry (Thaiclinicaltrials.org) under registration number TCTR20201230002.