Synthesis And Properties Of Press Sensitive Adhesives And Hydrogel For Transdermal Drug Delivery Systems

Transdermal drug delivery system (TDDs) has received much attention in drug release because of several advantages. The serious lack of polymer materials used in TDDs is a big bottle-neck problem embarrassing the development of TDDs. In this paper the skin compatible hydrophilic polyurethane pressure sensitive adhesives (PSAs) and two types of polyvinyl alcohol (PVA) hydrogel were studied in order to developed new materials for TDDs.The hydrophilic polyurethane PSAs were synthesized by polyaddition of polymer glycol, diisocyanate and extender. The effects, such as the kinds of the diisocyanates, the temperature, the reaction time and the ratios of the materials on the productions, were studied carefully in this work. The methods of rolling boll at a slope, peeling at 180°angle and cohesion test were used to evaluate the mechanical properties of PSAs. The transdermal drug delivery properties of the prepared PSAs were evaluated invitro by Franze diffuse method. The study results indicated that the hydrophilic polyurethane PSAs prepared in this paper show good mechanical and drug delivery properties, which suit for the TDDs application.Two types of PVA hydrogels, PVA-Ⅰand PVA-Ⅱ, were prepared by using borax and tetraethoxysilanes (TEOS) as crosslinkers. The mechanics and swelling behavior of the two gels, as well as their influence factors, were investigated. The transdermal release experiments were also performed in order to evaluate the drug compatibility and control drug release problem. The study results show that PVA-Ⅱhydrogel presents better performance in mechanics and swelling properties than PVA-Ⅰ, while PVA-Ⅰshows lightly higher drug release rate.