Halloysite–Iron Oxide Composites as Tetracycline Carriers. Adsorption Properties and Antimicrobial Activity In Vitro

A powdered halloysite/iron oxide composite has been synthesized by the chemical coprecipitation method. The sorption properties of halloysite and the composite have been studied with respect to tetracycline. The halloysite/iron oxide composite has been found to be a more efficient sorbent than halloysite. Mathematical processing of the experimental data has led to a conclusion that the kinetics of the sorption process can be described by the pseudo-first- or pseudo-second-order kinetic models. The antimicrobial properties of the synthesized composite samples with respect to E. coli M-17 bacteria have been studied before and after tetracycline adsorption. It has been revealed that the saturation of the composite with the antibiotic leads to a decrease in the viability of bacteria.