Natural rubber-based pressure sensitive adhesive as a drug carrier

Abstract

Natural rubber (NR) has been utilized in several products from its interesting unique properties. This study aimed to develop the pressure-sensitive adhesives (PSA) as the transdermal patches from NR by two-roll mill kneading technique. Hydroxyethyl cellulose (HEC) was blended as a tackifier agent. The propranolol HCl and ibuprofen at different parts per hundred of rubber (phr) were loaded into this developed PSA. The appearance, thickness, crystallinity, contact angle, water sorption and erosion, adhesion, and in vitro drug permeation of these patches were evaluated. The thickness of all patches was in the range of 0.46–1.07 mm. The drug-loaded patches showed diverse unique topographies depended on both type and amount of drug incorporation. From powder X-ray diffraction analysis, the plain NR-PSA showed the amorphous structure, while the halo pattern inserted with sharp drug peaks were observed on drug-loaded PSA. The contact angle of all samples was in the range of 80–90° indicating their hydrophobic surface. However, they displayed an increased % water sorption with the time of soaking. The 2–4 N adhesion force was evident for all fabricated drug-loaded PSAs. The propranolol HCl permeated from PSA notably lower than ibuprofen. The residual of the drugs in patches was about 85–90 %. These results provided the basic physicochemical properties for the further development of PSA as the transdermal patch.[copyright information to be updated in production process]