Transdermal delivery of captopril using poly(vinyl pyrrolidone)/poly(vinyl alcohol)-based dissolving and hydrogel-forming microneedles: A proof of concept

Captopril (CAP) is an angiotensin-converting enzyme (ACE) inhibitor that has been widely used to treat hypertension. Oral administration of CAP has been associated with bioavailability and frequency issues, affecting patient compliance. Thus, it is essential to investigate an alternative route for overcoming those problems, namely transdermal. Microneedles is a promising strategy to enhance skin permeation of hydrophilic drugs, such as CAP. This research aimed to develop poly(vinyl pyrrolidone)/poly(vinyl alcohol)-based dissolving microneedles (DMN) and hydrogel-forming microneedles (HFMN) with film reservoirs for delivering CAP transdermally. HFMNs were manufactured using poly(vinyl pyrrolidone) K-29/32 (PVP K-29/32), poly(vinyl alcohol) (PVA), and citric acid anhydrous. CAP was formulated into DMNs and film reservoirs (FD). CAP-loaded DMNs were manufactured using PVP K-29/32 and PVA. Meanwhile, CAP-containing FDs were prepared using PVP K-29/32, PVP K-90, and glycerol. The manufactured polymeric microneedles were evaluated in terms of their mechanical properties and the ability to deliver CAP in an in vitro study using Franz diffusion cells. Based on the in vitro studies, both HFMNs integrated with FDs (FD-1) and DMN-1 successfully delivered the CAP with the cumulative amount of drug permeated were 9.90 ± 0.31 mg and 7.49 ± 0.17 mg, respectively. Results revealed that both HFMN and DMN were able to deliver more than 50 % of CAP loaded. This research presents a novel insight, for the first time, by showcasing DMNs and HFMN as promising approaches for delivering CAP transdermally.