Resveratrol-Loaded Dissolving Microneedles: Fabrication and in vitro Evaluation

Abstract Resveratrol (Res), an active ingredient derived from a multitude of plants, exhibits multiple pharmacological activities. However, its poor water solubility and low bioavailability present significant challenges to its clinical application. Our study aimed to improve the transdermal absorption of Res using dissolving microneedle (MN) technology, which could effectively overcome the stratum corneum barrier. Res-loaded dissolving microneedles (Res-MNs) were fabricated using polyvinyl pyrrolidone K90 (PVP K90) as the matrix material, and a two-step casting procedure was employed. The process was optimized using the Box–Behnken experimental design approach. The characteristics of Res-MNs in vitro, including morphology, solubility, safety evaluation, and skin permeation, were studied. The results showed that the optimum preparation conditions of Res-MNs were a centrifugation time of 10 minutes, a solvent concentration of 25%, and a prescription ratio (Res: matrix) of 0.375. The skin permeability of the Res-MNs was enhanced compared with Res suspension and Res gel. The cumulative release of Res-MNs in vitro was 75%, which was approximately 5 and 3 times that of the Res suspension group and Res gel group. These results suggest that dissolving MNs may represent a potential approach for enhancing the transdermal delivery of poorly absorbed drugs such as Res.