Ordered Mesoporous Silica for the Delivery of Poorly Soluble Drugs

Ordered mesoporous silica (OMS) materials offer much promise as carriers for poorly soluble drugs because of their high porosity, large specific surface area, and uniform pore shape and dimensions. Liquid as well as solid type phases of drugs, confined and stabilized in the pores of OMS, can exhibit special physicochemical properties and enhanced dissolution rates compared to crystalline forms. The ability to design mesopore size precisely provides the formulation scientist with the potential to readily attain and closely control drug release. Absorption enhancement may require stable supersaturation of released drug. If this can be effected (viz. drug precipitation attenuated by suitable formulation adjuvants), systemic absorption can be enhanced. In vivo proof of concept of OMS as a dissolution-enhancing technology has been demonstrated in various animal species. The findings are promising and suggest that adsorption on OMS can successfully enhance and control absorption of poorly soluble drugs.