Polymeric microneedles for delivery of Risperidone : pharmaceutics, pharmaceutical analysis, nanomedicine and pharmacokinetics

Therefore, this thesis explores a novel approach involving the use of dissolving and hydrogel-forming microneedle array patches (MAPs) for the delivery of RIS. Nanocrystals (NCs) were developed and formulated into dissolving MAPs (DMAPs). Furthermore, directly compressed tablets (DCTs) were prepared from RIS and cyclodextrins (CDs) and combined with hydrogel-forming MAPs (HFMAPs) that were cast using different types of polymers and crosslinking processes.

MAPs were evaluated for their insertion efficiency, mechanical properties and ex vivo drug permeation and skin deposition using neonatal porcine skin. Based on the results, the lead DMAPs and HFMAPs with DCTs were selected for further investigation through in vivo pharmacokinetics studies using Sprague Dawley rats. Both RIS and its active metabolite 9-hydroxy risperidone (9-OH-RIS) were evaluated.

The result had shown, for the first time, the delivery of RIS transdermally via DMAPs for five days. HFMAPs were applied into two groups of rats one having the MAPs for one day and the other having the patch for five days. It was seen that the prolonged wear of the patches extended the release up to ten days compared to five days with one-day application.

Consequently, this thesis offers substantial evidence to support the broader application of MAPs for the transdermal delivery of poorly water soluble drugs.<br><br><i>Thesis is embargoed until 31 December 2028.</i>