Controlled slow release of chemotherapeutic drugs for cancer from matrices prepared by radiation polymerization at low temperatures.

The vinyl polymer-chemotherapeutic agent composites of various shapes (rod, tablet, membrane, microsphere, and powder) were prepared by radiation polymerization at low temperatures for the purpose of durable controlled slow release of drugs from implanted matrices. Bleomycin hydrochloric acid, mitomycin C, and 5-fluorouracil were tested as chemotherapeutic drugs entrapped in poly(diethylene glycol dimethacrylate) including a small quantity of a polymer such as poly(styrene), poly(vinyl formal), poly(vinyl acetate), poly(methyl methacrylate) on polyethylene glycol No. 600. The release rates from the matrices depended much on the kind of polymer, drug, and monomer concentration in polymerization and also on the shape of the composite. The release of these drugs from polymer matrices obeyed the diffusion-controlled release mechanism based on Higuchi's equation and was durable for more than thirty days. It was found that the release rate can be controlled easily by design of the shapes and structures of the polymer matrices.