Mesoporous silica formulation strategies for drug dissolution enhancement: a review

Abstract

Introduction: Silica materials, in particular mesoporous silicas, have demonstrated excellent properties to enhance the oral bioavailability of poorly water-soluble drugs. Current research in this area is focused on investigating the kinetic profile of drug release from these carriers and manufacturing approaches to scale-up production for commercial manufacture.

Areas covered: This review provides an overview of different methods utilized to load drugs onto mesoporous silica carriers. The influence of silica properties and silica pore architecture on drug loading and release are discussed. The kinetics of drug release from mesoporous silica systems is examined and the manufacturability and stability of these formulations are reviewed. Finally, the future prospects of mesoporous silica drug delivery systems are considered.

Expert opinion: Substantial progress has been made in the characterization and development of mesoporous drug delivery systems for drug dissolution enhancement. However, more research is required to fully understand the drug release kinetic profile from mesoporous silica materials. Incomplete drug release from the carrier and the possibility of drug re-adsorption onto the silica surface need to be investigated. Issues to be addressed include the manufacturability and regulation status of formulation approaches employing mesoporous silica to enhance drug dissolution. While more research is needed to support the move of this technology from the bench to a commercial medicinal product, it is a realistic prospect for the near future.

Keywords:

• dissolution
• loading method
• mesoporous silica
• poorly water-soluble drugs
• solid dispersion

Article highlights

• Mesoporous silica has demonstrated excellent properties to enhance the dissolution rate of poorly water-soluble drugs.

• Pore diameter, pore volume and surface area are key parameters for controlling drug loading and release from mesoporous carriers.

• Kinetic studies to date have reported a biphasic release profile from mesoporous silica.

• It is important to control the rate of drug release from the pores in vivo to enhance absorption of drug across the intestinal wall.

• More research is required to investigate incomplete drug release from mesoporous carriers.

• Challenges exist to scale up production for large-scale manufacture.

This box summarizes key points contained in the article.

Acknowledgements

The authors wish to acknowledge Dr. Joe Tobin, Glantreo Ltd., for creating TEM images of mesoporous silica and permitting their inclusion in this review.