ANTIBIOTIC DELIVERY SYSTEM USING BIOACTIVE BONE-CEMENT CONSISTING OF BIS-GMA TEGDMA RESIN AND BIOACTIVE GLASS-CERAMICS/

A novel drug delivery system containing cephalexin (CEX) as a model dr ug using a new bioactive bone cement consisting of 15% bisphenol-alpha -glycidyl methacrylate (Bis-GMA), 15% triethylene-glycol dimethacrylat e (TEGDMA) resin and 70% apatite-and wollastonite-containing glass-cer amic (A-W GC) powder was investigated. A-W GC powder containing CEX po wder hardened within 5 min after mixing with Bis-GMA/TEGDMA resin, and furthermore its compressive strength was expected to be higher than t hat of polymethylmethacrylate cement. In vitro CEX release from bioact ive bone cement pellets in a simulated body fluid at pH 7.25 and 37 de grees C continued for more than 2 weeks. The drug release rate increas ed with increasing amount of CEX in the mixture. All of the drug relea se profiles followed the Higuchi equation at the initial stage, but no t at later stages. As hydroxyapatite was precipitated out on the cemen t surface, the drug release rate decreased. These results suggest that the CEX release rate from bioactive bone cement could be controlled b y varying the amount of drug in the cement system. (C) 1997 Elsevier S cience Limited. All rights reserved.