Preparation of chitosan-coated hollow tin dioxide nanoparticles and their application in improving the oral bioavailability of febuxostat

The aim of this study was to design a chitosan-coated hollow tin dioxide nanosphere (CS-HSn) for loading febuxostat (FEB) using an adsorption method to obtain a sustained-release system (CS-HSn-FEB) to improve the oral bioavailability of FEB. The morphological characteristics of hollow tin dioxide nanospheres (HSn) and CS-HSn were analyzed by transmission electron microscopy (TEM) and dynamic light scattering (DLS). The hemolysis test and CCK-8 test were used to assess the biosafety of HSn and CS-HSn. Powder X-ray diffraction (PXRD) and differential scanning thermal analysis (DSC) were performed on CS-HSn-FEB to analyze the drug presence status. The dissolution behavior and changes in plasma drug concentration of CS-HSn-FEB were evaluated in vitro and in vivo. Sections of intestinal tissues from SD rats were obtained to observe whether chitosan could increase the distribution of nanoparticles in the intestinal tissues. The results showed that FEB was present in CS-HSn in an amorphous state. Moreover, CS-HSn, with good biosafety, significantly improved the water solubility and oral absorption of FEB, indicating that CS-HSn has great potential to improve the intestinal absorption and oral bioavailability of insoluble drugs.