In Vitro Pharmacokinetics of Vancomycin Release from Locally Implantable Materials

Local deposition of antibiotics has become increasing popular in the management of open fractures or osteomyelitis, and several substances have been employed as the vehicle for delivery. Although the elution characteristics of some substances have been documented, a comparative study of the characteristics of the commonly used substances were performed in order to establish the clinical indications for particular vehicles. Carriers were prepared, which were human iliac cancellous bone, bovine cancellous bone matrix(Lubboc?), absorbable gelatin sponge(Gelfoam?), fibrin glue(Beriplast? P) and polymethylmethacrylate(CMW?) for elution characteristics of vancomycin. The each carriers were immersed on the 20 ml of PBS and then obtained the samples for analysis of concentration of vancomycin at first, second, third, fourth, fifth, sixth, fourteenth, twenty-first, twenty-eighth day after immersion. The assay technique was fluorescent polarization immunoassay(Abbott, Dallas, Texas, U.S.A.). Nearly 50% of vancomycin was released from human iliac cancellous bone, Lubboc? and fibrin glue during the first 3 days, and negligible after first week. Gelatin sponge produced high local concentration of vancomycin during the first week. PMMA eluted the only 6% of vancomycin during the first day and trace amount detected as long as 4 weeks. There are significant statistical difference among carriers at second and fourth week(ANOVA test, P<0.05). The authors considered that human iliac cancellous bone, Lubboc? ,Gelfoam? and fibrin glue may be best employed when brief antibiotic coverage is required, whereas PMMA may be better suited for long-term coverage.