The efficacy of a hydroxyapatite composite as a biodegradable antibiotic delivery system

Local biodegradable carriers have been studied for use as a skeletal drug delivery system. This study investigated the efficacy of a local biodegradable composite composed of hydroxyapatite, plaster of Paris, and chitosan impregnated with antibiotics to treat methicillin-resistant Staphylococcus aureus. The composite, impregnated with vancomycin, fosfomycin, or sodium fusidate was tested for its sustained elution characteristics during 3 months and compared with similarly impregnated polymethylmethacrylate using the modified disc diffusion technique. Physicochemical properties using scanning electron microscopy and xray diffraction analysis of each preparation also were analyzed. Vancomycin and fosfomycin incorporated into the hydroxyapatite composite inhibited the organism for 3 months, whereas sodium fusidate was effective only for 3 weeks. Vancomycin and fosfomycin loaded into the hydroxyapatite composite had a significantly better inhibitive effect than when loaded in polymethylmethacrylate, whereas sodium fusidate loaded in polymethylmethacrylate showed a significantly better inhibitive effect than when loaded in the hydroxyapatite composite. Scanning electron microscopy and xray diffraction analysis elucidated the patterns of each drug release profile. The local hydroxyapatite composite is a promising local biodegradable delivery system for vancomycin and fosfomycin, whereas PMMA is a better carrier for sodium fusidate in treating methicillin-resistant staphylococcus aureus osteomyelitis.