Ordered mesoporous silica and aluminosilicate-type matrix for amikacin delivery systems

Abstract

Amikacin, which belong to aminoglycosides class of antibiotics, was used to obtain drug delivery systems based on MCM-41-type supports. In order to study the factors that influence the adsorption and in vitro release of amikacin, a series of mesostructured silica and aluminosilicates were employed as carriers. The toxicity of the supports was evaluated by proliferation tests on murine fibroblastic cells (3T3) and no significant toxic effect was observed. Small-angle and wide-angle X-ray diffraction data, N2 adsorption/desorption isotherms, as well as DSC analyses proved the presence of drug molecules in amorphous state into the channels of mesostructured MCM-41-type supports. It was found that the amikacin uptake depends mainly on the total pore volume of the carrier. The aluminum content in the mesostructured matrix with average pore size smaller than 2.4nm is favorable to the drug uptake. In vitro release profiles in phosphate buffer solution, pH 7.4, exhibited a burst effect of 40% drug in the first hour of the assay, followed by a slow rate of amikacin delivery. Slower release kinetics and a lower amikacin cumulative release amount from mesostructured aluminosilicates than silica carriers were noticed.