Synthesis of different types of calcium phosphates for the drug loading and releasing applications

Abstract

β-tricalcium phosphate and various forms of hydroxyapatites (HAps) were produced through the wet chemical precipitation method, using calcium hydroxide, orthophosphoric acid, cow bone, and fish scale as raw materials. The synthesized samples underwent characterization through x-ray diffraction, and their antimicrobial efficacy was assessed in powder form for gram-positive Staphylococcus aureus bacteria as well as gram-negative Escherichia coli bacteria. In vitro degradation tests were conducted using simulated body fluid after compressing the powdered samples into scaffolds and sintering at 900°C. These scaffolds were subsequently used to study drug loading and releasing over different periods. All scaffolds demonstrated strong loading capacities for amoxicillin (AMX) and ciprofloxacin (CIP), notably Rui bone HAp achieving 90.83% loading of AMX and cow bone HAp showing 98.73% loading of CIP. In contrast, both fluoride-doped HAp types displayed significant AMX release, whereas Rui bone HAp showed the highest CIP release. The pH and conductivity of drugs and drug-released SBF solution were examined after 21 days and 1 day, respectively.