Preparation of a Mesoporous Structure of SnO2 for Increasing the Oral Bioavailability and Dissolution Rate of Nitrendipine

In this study, mesoporous SnO2 (MSn) with a three-dimensional mesoporous structure was prepared using MCM-48 as the template in order to increase the oral bioavailability and dissolution rate of insoluble drugs. The model drug, nitrendipine (NDP), was loaded into the MSn by the adsorption method. The structural features of MSn were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and N-2 adsorption (desorption) analysis. NDP was existed in the pore channels of MSn in an amorphous state, which was characterized by powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR). MSn showed a good biocompatibility in the cell toxicity assay for Caco-2 cells. In vitro dissolution results suggested that MSn could significantly enhance the dissolution rate of NDP compared with commercial NDP tablets. Pharmacokinetic studies indicated that NDP-MSn tablets effectively enhanced the oral bioavailability of NDP. In conclusion, MSn was found to be a potential carrier for improving the solubility of insoluble drugs.