Nh4 2hpo4

Example 5

20 mL of 0.5 M calcium chloride (CaCl₂, Sigma, USA) was mixed with 20 mL of 0.2 M trisodium citrate (Na₃C₆H₅O₇, Fisher Scientific, India) and 0.1 M FeCl (Sigma, USA). Volume of 0.1 M FeCl₃ added was varied as per the required percentage of doping. 5 mL of 0.3 M diammonium hydrogen phosphate ((NH₄)₂HPO₄, S.D Fine Chemicals, India) mixed with 0.2 mL of 3 N ammonium hydroxide (NH₄OH, Fisher Scientific, India) was added drop wise to the above mixture of CaCl₂, Na₃C₆H₅O₇ and FeCl₃ under constant stirring to obtain Fe-nCX (X=phosphate). The precipitate was washed 4 times in hot distilled water by centrifugation at 8500 rpm for 15 minutes and redispersed in PBS. Zoledronic acid (1 mg/mL) was added to Fe-nCX solution and incubated at room temperature (22-37° C.) for 30 minutes. The zoledronic acid loaded Fe-nCX was then washed twice with distilled water to obtain the final product.