A NOVEL DRUG-DELIVERY SYSTEM FOR OSTEOMYELITIS USING POROUS HYDROXYAPATITE BLOCKS LOADED BY CENTRIFUGATION

A novel drug delivery system for osteomyelitis was developed using por ous hydroxyapatite blocks (HA-b) loaded with antibiotics by centrifuga tion. In the study, 10 mm(3) HA-b was placed in a container and mixed with antibiotic solution; the antibiotic was then loaded into the pore s of the HA-b by centrifuging at 1500 rpm for 15 min, Slow release of HA-b in both moist form and dried form (by heating at 160 degrees C wa s tested after loading with the antibiotic arbekacin sulfate (ABK), 1- N-(S)-4 amino-2-hydroxybutyryl dibekacin, To estimate the concentratio n of antibiotic, both forms of HA-b were placed in 3 mt of phosphate b uffered saline (PBS), which was replaced every 48 h, In both groups, w hich were loaded with 70 mg ABK per one block of HA (concn 0.5 mu g/mL ) which is sufficiently high to control most pathogens, was maintained for 21 exchanges of PBS (after 42 days), Minimum inhibitory concentra tion for methicillin-resistant Staphylococcus aureus (MRSA), 3.13 mu g /mL, was maintained until nine exchanges took place (after 18 days), T he centrifugation method is simple, and dried ABK produced by heating loaded HA-b is particularly useful in clinical applications for osteom yelitis. (C) 1995 John Wiley and Sons, Inc.