STUDY ON MICROSPHERES FOR EMBOLIZATION OF HEPATIC ARTERY

In this paper microspheres for embolization of hepatic artery have been prepared from gelatin and polyvinyl alcohol by emulsion polymerization, and systematic studies on the pharmaceutical aspects of microspheres, including the manuiacturing procedures, microsphere size and size distribution, drug incorporation, determination of the drug in the microspheres, their dissolution in vitro and the stability during sterilization by gamma radiation were conducted, By orthogonal designs on several factors affecting size and size distribution, optimal procedures in preparing microspheres with special size have been established. Using methotrexate and 5-fluorouracil as the model drugs, the release characteristics of gelatin microspheres were investigated. By complex chemical cross-linking the release of drug from microspheres could be delayed.The pathologic examination showed that microspheres infused via a percutaneously introduced catheter into the hepatic artery could occlude muscular arterioles before hepatic blood sinuses. Angiography which was performed before and immediately after each embolization illustrated that the branches of hepatic artery disappeared to a variable extent. γ-Ray scanning also illustrated the special localization of ^99mTc labelling microspheres in liver.