Monoolein-water liquid crystalline gels of gentamicin as bioresorbable implants for the local treatment of chronic osteomyelitis: In vitro characterization

To maximize the efficacy of chronic osteomyelitis antibiotherapy while reducing antibiotic systemic toxicity, as well as time and costs of hospitalizations, it has been thought that monoolein-water gels incorporating gentamicin sulfate could be used as local, bioresorbable, and sustained-release implants. For this purpose, four formulations were examined with regard to their physicochemical and in vitro drug release characteristics. Hot stage microscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and X-ray diffraction showed cubic liquid crystalline and eutectic structures. The more suitable formulation consisting of 80-15-5% wt/wt monoolein-water-gentamicin sulfate progressively released the antibiotic for a period of 3 weeks without burst effect. Moreover, the content and the release profile of gentamicin sulfate were not significantly changed after storage at 2-6 degrees C for a period of 10 months.