In situ precipitated hydroxyapatite-chitosan composite loaded with ciprofloxacin: Formulation, mechanical, in vitro antibiotic uptake, release, and antibacterial properties

Three-dimensional hydroxyapatite-chitosan (HA-CS) composites loaded with ciprofloxacin antibiotic (HA-CS-CIP) were formulated using the in situ and the solid-liquid method coupled with the freeze-drying process. The interaction of the HA-CS composite powder and ciprofloxacin antibiotic (CIP) was investigated by batch adsorption essays. The kinetic and the isotherm data were fitted well to the pseudo-second-order and Freundlich models, respectively. The compressive strength of the HA-CS composite was increased by 7-fold and 10-fold when using respectively 15 wt% and 30 wt% of the polymer compared to the HA-CS5 formulation (3.6 +/- 0.7 MPa) made only from HA powder and CS gel (5 wt%). However, this parameter decreased from 36.8 +/- 8.5 MPa down to 20.5 +/- 4.7 MPa when the antibiotic content increased from 0 up to 9 wt%, respectively. The in vitro release results showed a sustained and controlled CIP release for up to 10 days. The release data fitting and modeling indicate that the process follows a Fickian diffusion mechanism. Also, the formulated composite revealed an antibacterial effect against Staphylococcus aureus and Escherichia coli bacteria. The developed

Automated summary

Hydroxyapatite-chitosan composites loaded with ciprofloxacin antibiotic were successfully formulated and showed enhanced compressive strength and sustained release of ciprofloxacin. The composites also exhibited good antibacterial effects against Staphylococcus aureus and Escherichia coli bacteria.