Osteomyelitis is a bone inflamation process caused by microorganism infection. Osteomyelitis will lead to bone damage. Ciprofloxacin as local antibiotic delivery system (implant) is an effective way for osteomyelitis therapy. Composite implants consist of bovine hydroxyapatite and chitosan combination has physical characteristics suitable for ossification. Cross-linked chitosan can control  drug release. Genipin can be used for chitosan cross-linker. This study aims to determine influence of genipin concentration in bone implant to microbial activity ciprofloxacin towards Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923. In the previous studies, implants were made from ciprofloxacin 10% formulated into chitosan-bovine hydroxyapatite (60:30) composites with genipin 0.3% and 0.5% as cross-linker. Result showed that the implant had released ciprofloxacin in controlled condition with therapeutic window 2-50 μg/mL. The sample of released study was done with microbial assay by 3-3 design Agar Diffusion using hole-plate method.The result showed that the potency of ciprofloxacin towards Escherichia coli ATCC 25922 in bone implant Formula I (0.3% genipin), Formula II (0.5% genipin) were 106.62% and 106.42% respectively. And potency towards Staphylococcus aureus ATCC 25923 were Formula I 107.09%, Formula II 106.98%, respectively. Potency of four formulas meets the requirements for  antibiotic microbial assay that was 80-125%.

Keywords : ciprofloxacin-bone implant, chitosan-bovine hydroxyapatite, genipin, Staphylococcus aures ATCC 25923, Escherichia coli ATCC 25922