Calcium deficiency in hydroxyapatite and its drug delivery applications

In this work, calcium deficient hydroxyapatites (HAPs) [Ca10−x (PO4)6(OH)2] [where x = 0 − 0.3] were synthesised by precipitation method and calcined samples were characterised by Fourier transformation infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy and energy-dispersive X-ray spectroscopy techniques to check phase purity, calcium deficiency, particle size and shape. The results indicate that the structure of the HAP can tolerate a calcium deficiency up to 0.2. The calcium deficient HAP (x = 0.1) powder was found to be highly porous with a particle size below 200 nm. This powder was used as a drug delivery carrier for the drug, ciprofloxacin and sustained release of the drug in the phosphate buffer solution was investigated.