Controlling load and release of drugs by rapidly swellable microneedle patches for transcutaneous drug delivery

Abstract

Microneedles are increasingly popular drug delivery innovation that offers a number of advantages such as improved patient compliance and increased the range of drugs to be delivered transdermally. Among them, swellable MN was widely studied due to its biocompatibility and able to be removed completely intact after drug delivery. However, the current uses of swellable MN are mainly on ISF extraction for diagnosis purpose. In this study, the application of modified HA, MeHA swellable MN was extended to drug delivery. This paper shall present the proof of concept that swellable MeHA-MN can be used as a TDD system and is able to load and release drug controllably. The high water affinity of HA allows the photo crosslinked MeHA-MN patch to swell rapidly with the swelling mechanism controlled by the UV exposure time. Desirable amount of drug could be loaded and released simply by manipulating the photo-crosslinking duration. Fluorescence-tagged hydrophilic drugs, FITC/FITC Dextran with various molecular sizes were chosen to quantify the amount of drug and study the drug delivery mechanism in MeHA-MN. The greatest challenge of the project was to quantify the drug loaded. Nevertheless, a study on different concentration of drug solutions loading could be done to gain more insights of the loading mechanism in MeHA-MN. The release profile had shown that 15 minutes photo-crosslinked time is able to slow down the release of 10kDa drug more effectively. With TDD system gaining popularity, the application of MeHA MN would likely be welcomed to quantifiable drug release strategy.