PREPARATION AND CHARACTERIZATION OF CISPLATIN-LOADED POLYMETHYL METHACRYLATE MICROSPHERES

Non-biodegradable microspheres containing cisplatin were prepared by the solvent evaporation method, to achieve a sustained drug delivery system for local chemotherapy in bone tumors. Polymethyl methacrylate (PMMA) was chosen as coating material, since this polymer is widely used as a bone cement in orthopaedic surgery, particularly in total hip arthroplasty. The present study was carried out to show how various process parameters could influence the preparation of PMMA microspheres and their properties. Microsphere size and morphology were controlled by the nature and the concentration of the emulsifying agent. The amount of cisplatin that could be incorporated into the microspheres depended on the solubility of the drug in the aqueous phase and the rate of precipitation of PMMA at the droplet surface. The drug content was also influenced by the organic solvent: aqueous phase ratio. In vitro drug release was increased by addition of a porosity agent. The different parameters were optimized in order to achieve various drug release rates and high cisplatin loadings. Successful results were obtained with cisplatin, a highly water-soluble compound, whereas the solvent evaporation method is usually used for the entrapment of lipophilic drugs.