A Novel Malonamide Periodic Mesoporous Organosilica (PMO) for Tuneable Ibuprofen Release

Abstract

Incorporation of organic functionalities within porous materials is a very elegant manner to control the administration of therapeutic drugs. Delayed drug-release profile originates from weak and reversible interactions (e.g., electrostatic, hydrophobic-hydrophobic and H-bonding interaction) between the modified carrier and the drug molecule. Two new silsesquioxane PMO precursors were synthesized in a quick and facile Schotten-Baumann reaction of (3-aminopropyltriethoxy)silane and (N-methyl-3-aminopropyltrimethoxy)-silane with malonylchloride, respectively. Based on these bis(3-(triethoxysilyl)propyl)malonamide (MA) and N,N-dimethyl-N,Nbis(3-(triethoxysilyl)propyl)malonamide (mMA) precursors, an extensive range of 2D hexagonal PMOs with high functional loading was obtained by the co-condensation with tetraethyl orthosilicate (TEOS) in a typical PMO synthesis (acidic medium, P123, KCl). The materials showed good ordering up to 20 mol% of functional loading, a large surface area (up to 550 m 2 /g) and wide pores (∼7 nm). The malonamide-type PMOs are capable to adsorb large amounts of ibuprofen (130 mg/g) as a hydrophobic model drug. Release experiments are performed in a phosphate buffer solution at pH 7.4 and show a controlled desorption of Ibuprofen over 24 hours; a largely expanded times pan compared to mesoporous silicas. Moreover, we are able to tune the release profile by varying the content of organic bridges in the PMO pores.