Abstract

A major challenge in pharmaceutical discovery and development in recent years has been the increasing number of poorly soluble candidates. Approximately 40% of marketed drugs and up to 90% of API’s currently in R&D phases have poor aqueous solubility. Since dissolution of the compound is required for absorption by the body, the limited solubility of the drug significantly affects the bioavailability when given via the oral route. While there are numerous technologies available for increasing the aqueous solubility of drugs, many either require special processing equipment (for example, melt extrusion or spray drying) or changing the chemical form of the drug (for example, utilization of a salt form rather than the free acid or base). 

A technology that is gaining more interest in pharmaceutical formulation science is the use of porous silica as a drug carrier. Silica has long been used in analytical laboratories as a tool for the separation and purification of compounds. The presence of pores in the nanometer size range gives the material a large available surface area for adsorption, diffusion, and dissolution. 

As new development in this direction, a drug delivery system based on a Silica carrier, which could be used as excipient for drug delivery applications in oral bioavailability enhancement of poorly soluble drugs will be presented. In this case, the drug is deposited onto the surface of the silica in an amorphous form and dissolves at a much faster rate than the crystalline form. Rapid dissolution and the resulting supersaturated state greatly increase the chance for higher bioavailability when this parameter is limited by aqueous solubility. 

As outcome of the results we can conclude that using silica as carrier for poor soluble APIs we are able to:

- Establish a state of the art technologies for enhancing solubility

- Overcoming the development trap: poor solubility and bioavailability of NCEs

- Examining new developments in inorganic carriers as a safe and effective option.