Investigation of adsorption of metronidazole on Chitosan - Halloysite nanocomposites and controlled release

Abstract

A novel nanocomposite drug carrier composing from chitosan (CTN) and halloysite nanotubes (HNTs) has been developed. For this purpose, the metronidazole (MNZ) is chosen as a model drug. The characterization of synthesized nanocomposites is performed by FTIR, TGA, DSC, SEM, TEM, BET and particle size distribution analysis. MNZ is loaded to chitosan-halloysite (CTN-HNT) nanocomposites in two ways; by direct loading and adsorption method. The adsorption of MNZ on CTN-HNT nanocomposites have been investigated as a function of medium pH, mass ratio of CTN to halloysite (HNT), amount of nanocomposite and drug concentration. The fit of MNZ adsorption equilibrium on CTN-HNT nanocomposites to the Langmuir and Freundlich models was investigated. The adsorption kinetics of MNZ on nanocomposites have been evaluated using the pseudo-first order rate equation of Lagergren and the pseudo-second-order rate equation of Mc-Kay and Ho. The controlled release of MNZ from CTN-HNT nanocomposites has also been investigated.