Development of microcapsules containing oil-based contrast medium

For efficient transcatheter arterial embolization therapy for hepatocellular carcinoma, we have developed microcapsules containing oil-based contrast medium, as obstructing materials. The microcapsules were prepared by means of the interfacial polymerization to make a wall membrane consisting of polyureaurethane with Lipiodol in the core. The average size of the particles was 80 mu m, and the size distribution was fairly small. The extent of X-ray absorption of the microcapsules was controlled by the ratio of the amounts of triisocyanate monomer and Lipiodol in the oil phase on the interfacial polymerization.