Hydroxyapatite nanoparticles was also characterized by X-ray diffraction using a diffractometer (Xpert PRO MPD (Multi-Purpose Diffractometer)) at the X-Ray Diffraction Laboratory (LDRX) with a 16 mm sample holder, in a range of 20° ≤ θ ≤ 60°, step size of 0.04°, and step time of 0.12 s. From diffractograms, the crystallite size was calculated using the Scherrer Equation.