Facile synthesis of 3D cubic mesoporous silica microspheres with a controllable pore size and their application for improved delivery of a water-insoluble drug.

A facile and simplified method was developed for the synthesis of 3D cubic mesoporous SBA-16 with both a spherical morphology and controllable pore size. The addition of CTAB during the synthesis allowed not only good control over the macroscopic morphology but also a significant reduction in the synthesis time. Notably, the pore size can simultaneously be adjusted by simply controlling the heating temperature. The pharmaceutical performance of the resulting SBA-16 for the delivery of the water-insoluble drug indomethacin (IMC), a non-steroidal anti-inflammatory agent used as a model drug, was systematically studied using nitrogen adsorption, powder X-ray diffraction, differential scanning calorimetry, infrared spectrometry and in vitro dissolution investigations. It was found that IMC could be effectively loaded into mesoporous SBA-16 via the solvent deposition method. An altered physical state and a marked improvement in the dissolution rate were observed for IMC after being loaded into SBA-16 microspheres. In particular, SBA-16 microspheres with the largest pore size (9.0 nm) and highly open and accessible pore networks exhibited the fastest drug release profile. We envisage that the improved drug delivery profiles obtained using SBA-16 as described in our work will offer an interesting option for the formulation of poorly water-soluble drugs.