Fig. 2

Characterization of SHAP-CLB. (A) The X-ray diffractogram of the hydroxyapatite (HAP) sample obtained after using the co-precipitation method was compared with that of the Joint Committee on Powder Diffraction Standards (JCPDS) card number 09-0432 for HA. (B) FTIR spectra of HAP, stearic acid, SHAP, CLB, and SHAP-CLB were analyzed. Characteristic absorption bands of HAP were observed in the 600–1100 cm^− 1 region. Characteristic absorption bands of stearic acid were identified at 1700, 2848, and 2917 cm^− 1. (C) Particle size and morphology. SEM images of SHAP-CLB were captured at 50,000× magnification (scale bar = 500 μm). The images reveal an open and interconnected porous structure for SHAP-CLB. (D) The size distribution of SHAP-CLB particles was determined by analyzing DLS data, which indicates that the particle size was within the 500 − 1500 nm range. (E) TGA analysis revealed that the weight loss of SHAP-CLB was 13.01% at a temperature of 263.05 ºC, indicating the percentage of CLB loaded in SHAP. (F) The drug release profile of SHAP-CLB showed that approximately 12% of CLB was released on the first day at pH 7.4, after which, no further release was observed. However, in an acidic environment (pH 3), SHAP-CLB dissolved and released around 80% of the loaded CLB within 7 days, mimicking the endocytic process of the endosome/lysosome complex