OBJECTIVETo investigate the relationship of properties and drug release rate of hot melt pressure sensitive adhesive (HMPSA), and to provide a recommendation of preparing and selecting of HMPSA for transdermal use.

METHODHMPSA with different properties were prepared using styrene-isoprene-styrene triblock copolymer as main material, and the tacks, adhesions and cohesions were determined. Drug-in-adhesive type patches were prepared using alpha-asarone as model drug, and the drug release rates were investigated on single chamber diffusion cells using 60% ethanol solution as release media.

RESULTThe prepared HMPSAs had different tacks, adhesions and cohesions. The drug release rates of HMPSA patches were related to the cohesions. The release rate decreased when the cohesion increased.

CONCLUSIONThe HMPSA with appropriate cohesion should be selected when preparing patches to balance the drug release rate and patch property.