Chitosan blending with water-soluble polymers as dissolving microneedles for controlled drug release

Abstract

Chitosan has gained significant interest due to its ability to film-forming, biodegradability, and biocompatibility, making it suitable for topical and transdermal drug delivery such as fabricating microneedles. In this study, chitosan microneedles were prepared by incorporating polyvinylpyrrolidone (PVP) and polyvinyl alcohol (PVA) in three different ratios (1:1, 2:1, and 3:1 chitosan: polymers) to control drug release. The microneedles were fabricated using a molding method, their mechanical properties were tested using the universal testing machine (UTM), and their skin penetration ability was tested using pig skin (ex vivo). The results indicated that the microneedles exhibited sufficient strength to penetrate the outer layer of the porcine skin effectively. The study included incorporating two drugs: curcumin as a model of hydrophobic drugs, and butterfly pea extract as a model of hydrophilic drugs. Chitosan blended with PVP demonstrated the ability to finely tune the release profiles with approximately 90% of hydrophilic and 60% of hydrophobic loaded drugs being released from the microneedles over four days. In contrast, chitosan blended with PVA did not exhibit a significant difference from the blank microneedles, releasing only 49% of the loaded drugs over two days. These findings suggest that chitosan microneedles incorporating PVP are a promising candidate for controlled transdermal drug delivery, offering versatility in releasing both hydrophobic and hydrophilic compounds.