CISPLATIN-LOADED POLY(METHYL METHACRYLATE) IMPLANTS - A SUSTAINED DRUG-DELIVERY SYSTEM

We investigated the possible use of a local chemotherapy in the treatm ent of malignant lesions in bone. Therefore, the diffusion of cisplati n from polymethyl methacrylate implants was studied in vitro and in vi vo in rabbits. Cisplatin-loaded implants were prepared by extemporaneo us polymerization of methyl methacrylate added to a poly( methyl metha crylate)/drug blending. The in vitro release rate of cisplatin was ver y slow and incomplete, but increased when the drug loading was higher, suggesting a percolation release model. In vivo, drug-loaded implants showed sustained release characteristics and no plasma peak, compared to control intravenous cisplatin administration. After implantation, local concentrations of platinum were higher in bone marrow than in bo ne tissue. Comparative safety studies with cisplatin infusion showed a slight, but not clinically significant, renal and haematologic toxici ty for drug-loaded implants.