ABSTRACT
BACKGROUND:Antibiotic loaded bone cement has been well studied in clinical prevention and treatment of postoperative infection after artificial joint replacement. However, little is reported on antituberculotic-loaded bone cement. OBJECTIVE:To investigate the drug release properties of polymethyl methacrylate bone cement carrying antituberculosis drugs in a simulated body fluid (phosphate buffer solution, PBS). METHODS:The bone cement SimpLex P and antituberculosis drugs, including pyrazinamide, isoniazid, rifapentine, prothionamide, capreomycin, rifampicin, moxifloxacin, and amikacin, were mixed at 40 g:1.5 g and 40 g: 2.5 g ratios to prepare 16 groups of experimental specimens (n=5 per group). In addition, 40 g of bone cement powder was mixed with the liquid monomer to prepare a group of non-loaded bone cement specimens (control group,n=5). Either experimental or control specimens were soaked in PBS simulated body fluid, and then the extractions were taken at different time points to measure concentrations of antituberculosis drugs by high performance liquid chromatography. RESULTS AND CONCLUSION:The effective sustained-releasing time in the PBS simulated body fluid was 45 and 60 days for 1.5 g and 2.5 g groups of pyrazinamide, was 60 and 45 days for 1.5 g and 2.5 g groups of isoniazid, was 60 and 45 days for 1.5 g and 2.5 g groups of rifapentine, was 150 and 150 days for 1.5 g and 2.5 g groups of protionamide, was 150 and 150 days for 1.5 g and 2.5 g groups of capreomycin, was 45 and 60 days for 1.5 g and 2.5g groups of rifampicin, was 90 and 90 days for 1.5 g and 2.5 g groups of moxifloxacin, and was 60 and 90 days for 1.5 g and 2.5 g groups of amikacin, respectively. All the drug carriers had good drug release characteristics. Especially the 1.5 g and 2.5 g groups of protionamide, 1.5 g and 2.5 g groups of capreomycin, 1.5 g and 2.5 g groups of moxifloxacin and 2.5 g group of amikacin showed a longer period of drug release in accordance with the clinical need. However, our preliminary findings showed that the mechanical strength of the composite bone cement was considerably reduced by isoniazid, rifampicin, rifapentine, or protionamide, while the SimpLex P bone cement carrying pyrazinamide, amikacin, moxifloxacin, or capreomycin showed no changes in the mechanical strength. Therefore, pyrazinamide, amikacin, moxifloxacin, and capreomycin are suitable for the preparation of bone cements carrying antituberculosis drugs.