The hydrothermally synthesized SBA-15 particles were surface functionalized by post-grafting synthesis method with (3-aminopropyl) triethoxy silane, mercaptopropyl trimethoxy silane and triethoxy methyl silane in order to be used as carrier materials for drug delivery. Amoxicillin was used as a model drug. The adsorption and release properties of calcined and organic-functionalized mesoporous silicas containing terminal primary amine, organothiol and methyl groups toward amoxicillin have been investigated. These mesoporous materials have been characterized using small-angle X-ray scattering (SAXS), fourier-transform infra-red spectroscopy (FT-IR), transmission electron microscopy (TEM), N-2 adsorption/desorption analysis, solid-state silicon magic-angle-spinning nuclear magnetic resonance (Si-MAS-NMR), high-performance liquid chromatography (HPLC), ultra-violet spectroscopy (UV), elemental and thermogravimetric analysis (TGA). The concentration difference and type of alkoxysilanes used for the surface functionalization have been discussed in terms of loading amoxicillin and controlling its delivery. Crown Copyright (C) 2012 Published by Elsevier Inc. All rights reserved.