Targeted sustained delivery of tobramycin at the site of a femoral osteotomy.

Complex fractures are difficult to manage because of the increased risk of secondary infection. Traditional treatments include debridment and local administration of antibiotics. Local antibiotic therapy is a safe technique resulting in high local concentration of antibiotics with minimal systemic levels. Local antibiotics effectively control infection in animal models. The length of implantation and the need for removal of the delivery vehicle places the patient at risk for additional surgical procedure as well as delays the fixation procedure. Development of a bioresorbable carrier that can deposit therapeutic concentrations of antibiotics locally without side-effects will provide positive outcomes for the patient. Tricalcium phosphate lysine (TCPL) ceramic capsules containing tobramycin were implanted at the site of a femoral osteotomy delivered therapeutic concentrations of the drug locally and reduced the incidence of infection compared to TCPL capsule which were uncharged by 50%. In addition, the ceramic material was osteoconductive and animals in TCPL + TOB and TCPL carrier alone showed evidence of osteoblast alkaline phosphatase activity for a period of 15 weeks. Neither the carrier nor the carrier containing antibiotics displayed untoward effects on body weight, vital organs and reproductive organs over a 15 week period. The results from this study demonstrated that TCPL can be used as an effective osteoconductive material capable of delivering therapeutic concentrations of antibiotics over 15 week period.