Hydrogel-based microneedles of chitosan derivatives for drug delivery

Hydrogel-based microneedles have been developed to enhance the effectiveness of transdermal drug delivery in various applications due to its ability to penetrate skin's stratum corneum layer as well as their superior biocompatibility. In this study, natural polymers, Chitosan (CS) and Pullulan (PL) were used as raw materials to prepare hydrogels, among which two CMCS-SFP/OPL hydrogels with good swelling and water rentetion properties as well as excellent biocompatibility were selected as substrates to prepare Salvia miltiorrhiza loaded hydrogel-based microneedles, HFM-1 and HFM-2. Skin insertion study and drug loading/release study were then conducted to evaluate the applicability of these hydrogel-based microneedles as drug delivery vehicles. Facile insertion of HFM-1 into newborn porcine skin was observed due to its excellent mechanical properties. Rapid drug release from HFM-1, which enables effective transdermal drug delivery was also exhibited, suggesting that natural polymer-based hydrogel-based microneedles are promising devices to realize efficient, painless, and biocompatible transdermal drug delivery.