Preformulation characteristics of the opioid growth factor antagonist-naltrexone hydrochloride: stability and lipophilicity studies

In the last twenty years mesoporous materials (e.g., silica, silicon, and to a lesser extent titanium) have been extensively investigated as possible carriers for controlled drug delivery purposes. The great benefits of these materials are their high surface areas and pore volumes with tunable pore sizes and easily functionalized pore surface properties, which allow high drug payloads and from very rapid to slow release kinetics for controlled drug release formulations. The present review focuses on recent research on the exploitation of mesoporous silica and silicon based materials for controlled drug release applications. In particular, fabrication processes of these materials, drug loading and drug release profiles and mechanisms, as well as further functionalization of the porous surface structures of the materials are surveyed. Several examples of drug delivery formulations, together with drug release mechanisms, such as sustained release and stimuli-responsive controlled-release, are also presented herein.