Deproteinized Natural Rubber as an Electrically Controllable, Transdermal Drug-Delivery Patch

Abstract

A soft transdermal drug-delivery (TDD) patch composed of deproteinized natural rubber (DPNR) was fabricated in this work. Sulindac (Sul), an anionic drug, was loaded on the DPNR patch using silicone oil as a plasticizer. The in vitro release-permeation behavior of Sul from the Sul-loaded DPNR patch was studied by using a modified Franz diffusion cell at a pH of 7.4 and temperature of 37 °C. A cytotoxicity test of the DPNR with silicone oil (DPNR-Si) patch was performed, and the viability percentage was 90%. When external electrical potentials of 0–9 V were applied, the maximum amounts of Sul released and permeated from the Sul-loaded DPNR patch were 8.34, 10.16, 11.86, 19.84, 54.73, 70.89, 82.25, and 83.02% for electrical potentials of 0, 0.1, 0.3, 1, 3, 5, 7, and 9 V, respectively. The release and permeation amount of Sul increased with the increasing electrical potential because of the electrorepulsive force, expanded pathway in pigskin, and pore formation in DPNR. Pore formation occurred under an applied electric field, as confirmed by optical micrographs. The porosity percentage increased with the increasing time and electrical potential due to the drug release and permeation and lack of plasticizer. The effect of storage time on the permeation characteristics was studied for 3 months. The release and permeation amount of Sul was 8.61 and 6.80 wt% for storage times of 1 and 3 months, respectively. Thus, the fabricated Sul-loaded DPNR patch is an electrically controllable TDD patch.