Effective controlled release of captopril by silylation of mesoporous MCM-41

The release of the water-soluble drug Captopril is controlled by tailoring the surface properties of mesoporous silica via stepwise silylation. The degree of silylation is manipulated by adjusting the initial concentration of silylanizing reagent (trimethylchlorosilane, TMCS). The silylanized and drug-loaded samples are characterized by powder X-ray diffraction, Fourier transform IR spectroscopy, N-2 adsorption and desorption, Si-29 cross-polorization magic angle spinning NMR spectroscopy, and transmission electron microscopy. The drug-loading amount is correlated to the Brunauer-Emmett-Teller surface area and surface hydrophilicityl hydrophobicity of the mesoporous silica material, while drug release profiles con be controlled by tailoring the surface properties and pore size.