Development and Optimization of Polymer-Based Dissolving Microneedles Fabricated by Mold Casting Method

Abstract

Microneedle systems represent a promising minimally invasive approach for transdermal drug delivery; however, their performance strongly depends on the composition and mechanical properties of the polymer matrix. The aim of this study was to select an optimal polymer composition for the fabrication of dissolving microneedle arrays produced by the mold casting method. The study focused on evaluating mechanical strength, dissolution behavior, and penetration efficiency of different polymer systems. Microneedle matrices were fabricated using polyvinylpyrrolidone (PVP K-30), methylcellulose, sodium alginate, and hyaluronic acid at various concentrations, alone and in combination. No active pharmaceutical ingredient (API) was incorporated; the study was performed using blank polymeric systems intended for subsequent drug loading. The microneedles were manufactured using 3D-printed and silicone molds. Their performance was evaluated by in vitro dissolution testing, pH measurement, penetration studies in gelatin gel and Parafilm M models, and mechanical compression testing. Monopolymer systems demonstrated either rapid dissolution with insufficient mechanical strength or improved strength at the expense of prolonged dissolution time. Combined polymer formulations showed superior structural uniformity and balanced performance. In particular, the system containing 5% PVP K-30 and 10% sodium alginate demonstrated the best overall characteristics, achieving high penetration efficiency (up to 96%), uniform dissolution (78%), and appropriate dissolution time (8.5 ± 0.5 min). Addition of hyaluronic acid further improved structural uniformity and handling properties. The results indicate that composite polymer matrices provide an optimal balance between mechanical stability, penetration ability, and dissolution rate. The formulation consisting of 5% PVP K-30 and 10% sodium alginate was identified as the most promising base for further development of drug-loaded dissolving microneedle systems.