Amorphous microporous silica materials for oral controlled release

Oral drug administration is the most important method of administering drugs for systemic therapy. Control over the release of the active pharmaceutical compound during passage through the gastrointestinal tract is very important. However, contemporary controlled release technology has limited flexibility to tune the release of the active agent to the desired absorption profile. The general aim of this work is to assess the potential of amorphous microporous silica (AMS) materials for achieving a better control over the release of small organic bioactive compounds. Ibuprofen was selected as model compound in the study. AMS materials with variation in microporosity were prepared using an acid-catalyzed sol-gel procedure departing from tetraethoxysilane. The silicas were fined to specific particle sizes by crushing and sieving. AMS materials were loaded with 10 wt% ibuprofen either by uptake of molten ibuprofen or by adsorption of ibuprofen from a methylene chloride solution. The physical state of ibuprofen in the loaded AMS materials was analyzed using DSC.