Development of enhanced dissolving microneedles for effective transdermal delivery of therapeutic agents

Abstract

Intradermal injections for therapeutic drug delivery have been widely used due to its high loading capacity with easy accessibility. Dissolving microneedles (MNs) have been applied to an alternative to hypodermic needles, offering a simple, minimally invasive method with higher drug storage ability than other microneedle types. In this study, dissolving MNs for transdermal delivery were developed based on aqueous solutions of polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP). For the local anesthesia model, lidocaine was loaded into dissolving MNs, which contained a higher amount of drug than previous MN works while minimizing wastage and enabling a rapid release of the drug. Moreover, these dissolving MNs highly preserved the drug for a couple of months at all the different temperature conditions. For the improvement of dermal cancer treatment, the cationic polymer-based novel MN design was utilized to insert DNA drugs more fully into the skin by localizing therapeutic plasmid DNA in the MN tips. The dissolving MNs in these works can contribute to overcoming the drawbacks of existing intradermal drug delivery applications with an improvement on drug storage, loading amount, and delivery efficiency.