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

A novel drug delivery system for osteomyelitis was developed using porous hydroxyapatite blocks (HA-b) loaded with antibiotics by centrifugation. 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 pores 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 was tested after loading with the antibiotic arbekacin sulfate (ABK), 1-N-(S)-4 amino-2-hydroxybutyryl dibekacin, To estimate the concentration of antibiotic, both forms of HA-b were placed in 3 mt of phosphate buffered saline (PBS), which was replaced every 48 h, In both groups, which 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 concentration for methicillin-resistant Staphylococcus aureus (MRSA), 3.13 mu g/mL, was maintained until nine exchanges took place (after 18 days), The centrifugation method is simple, and dried ABK produced by heating loaded HA-b is particularly useful in clinical applications for osteomyelitis. (C) 1995 John Wiley and Sons, Inc.