The Utility Of Mesoporous Silica Materials For The Delivery Of Poorly Water Soluble Drugs

By Michiel Van Speybroeck Ph.D. , R&D Director, Formac Pharmaceuticals

It is estimated that around 70% to 90% of new chemical entities in discovery pipelines and 40% of drugs on the market are poorly soluble in water. Poor aqueous solubility may drastically limit oral bioavailability and ultimately compromise therapeutic outcome. It is becoming increasingly apparent that the adsorption of poorly water soluble drugs on mesoporous silica materials is a very effective way to address this solubility problem.

What are mesoporous silica materials?

Silica is the common name for silicon dioxide (chemical formula SiO₂). Mesoporous means that these materials have pores with a diameter between 2-50 nm (IUPAC definition). Mesoporous silica materials are usually produced via precipitation from a sodium silicate solution under acidic conditions. In some cases, a template (for example a polymer) can be added during the silica precipitation process. This gives rise to pores that are highly uniform in size as well as in shape, and the resulting materials are therefore referred to as ordered mesoporous silica materials. Due to their network of countless nanosized pores, mesoporous silica materials exhibit an extremely high surface area: one table spoon of a mesoporous silica material may have a surface area greater than an American football court.