The current antibiotics delivery system for orthopedic infection treatment
uses polymethylmethacrylate (PMMA) beads as a drug release. However the non
biodegradable nature of the PMMA necessitates a second operation to remove
the beads. This article explores the alternative of using biodegradable pol
ymers as antibiotic beads for a long-term drug release. The effect of diffe
rent processing factors on the release rate of the beads was investigated,
To manufacture an antibiotic bead, polylactide-polyglycolide copolymers wer
e mixed with vancomycin, The mixture was compressed and sintered at 55 degr
ees C to form beads of different sizes. An elution method was employed to c
haracterize the release rate of antibiotic over a 35-day period at 37 degre
es C. Biodegradable beads released high concentrations of antibiotic (a ell
above the breakpoint sensitivity concentration) in vitro for the period of
time needed to treat bone infection; i.e., 4-6 weeks. A bacterial inhibiti
on test was carried out to determine the relative activity of the released
antibiotics. The diameter of the sample inhibition zone ranged from 6.5-10
mm, which is equivalent to 12.5-100% of relative activity. By changing the
processing parameters, we mere able to control the release rate of the bead
s, This provides advantages of meeting the specific antibiotics requirement
for patients with various surgical infections. (C) 1999 John Wiley & Sons,
Inc.