Studies In Applicability Of Pressure Sensitive Adhesives To TCM-DTS

Skin delivery is divided into transdermal therapeutic systems (TTS) and dermal therapeutic systems (DTS) . TTS are non-conventional dosage forms intended to deliver a drug across the skin for systemic activity and DTS are dosage forms similar to TTS, for the topical treatment of skin diseases. Anti-pain Chinese traditional medicine plays an important role in DTS. The patches with chemical medicine require to improve the percutaneous penetration rate, and the TCM patch which is based on good adhesion is concerned in property release rate of one kind of components or different ones. The purpose of this study is to investigate the applicability of traditional Chinese medicine (TCM) in modern DTS and to provide technical support for preparing different TCM pressure sensitive adhesives which have better adaptability and controlled quality using modern DTS techniques.In this paper, Corydalis, Radix Aconiti, Sanqi, TPG as well as two other substances have been selected in Yunnan White Drug and tetrahydropalmatine, aconitine, paeoniflorin and ginsenoside rg1 are used as labeled components. TCM pressure sensitive adhesives have been made with acrylic ester or some different kinds of SIS-based thermosol as matrix. The effects of different matrices on the viscosity and in vitro release percentage of TCM components were investigated. We selected several solvent systems, the thermosol (KT-A, 2501, 2501s) were dissolved by stirring in the mixed solvent in experiment . The better mixed solvent system is determined as heptane: ethyl acetate = 3:7 (w: w) . Viscosity test shows that SIS as an addition can improve the viscosity of thermosol and the patch based on acrylic ester has better viscosity. The in vitro release experiments were carried out with Permcell diffusion cell. Results show that the patch based on acrylic ester takes up significant effects on alkaloid drugs, the components in KT-A matrix indicate good correlation between release rate and molecular weight. The 2501s patch presents a balanced accumulative release rate (29%-43% in 12h) . It was found that good components release rates were abserved with small molecular weight, weak interaction with the matrix and the receiving media easier penetration to the matrix. We find that thermosol have good applicability to TCM-DTS, and the Acrylic PSA shows better selection to one kind of components.