NAYAK AMIT KUMAR AND SEN KALYAN KUMAR
The present study was aimed to prepare, characterize, evaluate in-vitro drug adsorption and dissolution studies of hydroxyapatite (HAp)- ciprofloxacin minipellets for bone-implant delivery to treat various bacterial bone infections. Ciprofloxacin loaded hydroxyapatite powders were synthesized by precipitation technique varying different experimental conditions like drug amount added and addition rate of orthophosphoric acid as one of the starting material in the synthesis process. HAp-ciprofloxacin minipellets (2 mm X 2 mm X 1 mm) were prepared by compressing synthesized HAp-ciprofloxacin powders. Highest drug loading was observed 76.64 ± 0.47 % w/w with incorporation efficiency of 87.43 ± 0.18 % w/w. Characterization of this drug delivery was done by P-XRD and FT-IR spectroscopy. Even at the highest drug loading (76.64 ± 0.47 % w/w), ciprofloxacin was present in a non-crystalline state. The in-vitro ciprofloxacin adsorption by HAp powder was achieved maximum after 24 hours at various temperatures and found to follow Freundlich isotherm. The in-vitro ciprofloxacin release from various hydroxyapatite-ciprofloxacin minipellets was slow and sustained for several weeks. The drug release pattern from these minipellets was correlated well with Higuchi model. This proposed methodology provides advantage of producing high drug loading (% w/w) in the HAp-system to get effective drug concentration at the diseased bone site for a prolong period as well as to reduce the implant size with facilities of small surgery and decreased hospitalization period.
