Evaluation of ordered mesoporous silica as a carrier for poorly soluble drugs: influence of pressure on the structure and drug release.

Ordered mesoporous silica (OMS) materials are considered a promising drug delivery system for the dissolution enhancement of poorly soluble compounds. The purpose of the present work was to determine structural and behavioral changes of compressed OMS material necessary for the development of an immediate-release oral-dosage formulation. Two types of OMS materials (SBA-15 and COK-12) were subjected to pressures both in and beyond the tabletting region and characterized by nitrogen physisorption, scanning and transmission electron microscopy, small-angle X-ray scattering, and differential scanning calorimetry. Itraconazole was used as the poorly soluble model drug and the release process with respect to pressure was determined in vitro. The resulting decreased drug release due to increased pressure was recovered by incorporating a plastically deforming material such as microcrystalline cellulose in combination with croscarmellose sodium. These findings further elucidate the understanding of their structural behavior for the advancement as a drug delivery carrier.