Acrylate‐based pressure sensitive adhesive in fabrication of transdermal therapeutic system

Abstract An acrylate‐based pressure sensitive adhesive (PSA) was synthesized to incorporate in a design of a drug‐in‐adhesive (DIA) type transdermal therapeutic system (TTS) for nitrendipine and nicorandil in treatment of hypertension and angina pectoris, respectively. Solutions of 2‐ethylhexyl acrylate (EHA; 85% w/w), methyl methacrylate (MMA; 10% w/w), acrylic acid (AA; 3% w/w) and vinyl acetate (VA; 2% w/w) in either ethyl acetate, acetone or methanol were polymerized under free radical conditions to synthesize the PSA. The effects of solvent, reaction time, initiator concentration and reaction temperature on polymerization were studied. The resultant copolymers were characterized by 1 H‐NMR, IR, differential scanning calorimetry (DSC) and gel permeation chromatography (GPC) and the intrinsic viscosities, refractive index, peel strength, moisture uptake and skin irritation potential were determined. The PSA was used to develop DIA type patches for delivery of nitrendipine and nicorandil. The TTS were evaluated for thickness, weight, peel strength, moisture uptake, in vitro release and in vitro skin permeation through guinea‐pig skin. The copolymer found to effectively control the rate of drug release and the corresponding TTSs could be successfully employed in transdermal delivery of nitrendipine and nicorandil. Copyright © 2003 John Wiley & Sons, Ltd.