Comparative study of antibiotic-containing polymethylmetacrylate capsules and beads

Background: This study aimed at making local antibiotic therapy wider in cases of chronic suppurations by administering antibiotics which previously could not be given in this way through the conventional polymethyl-metacrylate ( PMMA) carrier techniques. Capsules from this material were produced with a pressing machine designed and laid out by us. The characteristics of antibiotic penetration from this novel carrier were compared to those of PMMA beads. Methods: The time-dependent outflow of amikacin, clindamycin, pefloxacin, piperacillin + tazobactam, amoxicillin + clavulanic acid and cefotaxime was examined from the capsules and the beads with standard microbiological techniques using the Micrococcus luteus ATCC9341 test strain. The diameter of the inhibitory zones was measured after 24 h incubation at 37 degrees C and converted to mu g/ml antibiotic concentrations. Results and Conclusions: Our results revealed that all antibiotics showed longer-lasting and higher concentration outflow from the PMMA capsules than from the beads. Therefore, these capsules can provide a more promising new opportunity for specific local antimicrobial treatment in cases of chronic suppurative bone and soft tissue injuries. In these cases the polymerization has already been completed and the heat does not influence the structure of the antibiotics; therefore, it can be inserted into the capsules in powder or solution form. Copyright (C) 2006 S. Karger AG, Basel.