In vitro and in vivo assessment of polymer microneedles for controlled transdermal drug delivery

AbstractMicroneedles (MNs) system for transdermal drug delivery has the potential to improve therapeutic efficacy, proving an approach that is more convenient and acceptable than traditional medication systems. This study systematically researched dissolving polymer MNs fabricated from various common FDA-approved biocompatible materials, including gelatine, chitosan, hyaluronic acid (HA) and polyvinyl alcohol (PVA). Upon application of MN patches to the porcine cadaver skin, the MNs effectively perforated the skin and delivered drugs to subcutaneous tissue on contact with the interstitial fluid. Both the in vitro and in vivo drug release tests showed the similar trends but different release rates among the prepared MNs. Interestingly, the drug-release kinetics of PVA MNs were able to be altered by changing the molecular weight. To evaluate the feasibility using the proposed MNs for treating diabetes, an in vivo insulin absorption study in diabetic mice was performed. The results showed different insulin r...