Sustained release of fleroxacin in vitro from lactic acid polymer.

The time-delayed release of fleroxacin, a newer fluoroquinolone, from a mixture of racemic D-L-Lactic acid is reviewed. Ten in vitro experiments for each fleroxacin concentration of 1% and 10%, were performed. Pre-formed D-L-Lactic acid, plus fleroxacin clots were preserved in sterile 1 cm diameter tubes with one ml of nutrient broth at 37 degrees C until they were fully disintegrated. Every 24 hours the tubes were sampled and replaced by standard broth volumes. Fleroxacin levels were measured by a microbiological method. The release of fleroxacin impregnated in D-L-Lactic acid clots in these two concentrations (1% and 10%) is very promising; the levels obtained over a two month period were much higher than the minimum bacterial concentration of the expected pathogens implicated in bone infections.