Metronidazole/clay nanocomposites: Synthesis, structure and antibacterial efficacy

Abstract Clays are materials commonly used in the pharmaceutical industry, either as excipients or as active substances. It was observed that when they are administered concurrently, they may interact with drugs reducing their absorption. Such interactions can be used to achieve technological and biopharmaceutical advantages, regarding the control of release. Interactions between clay minerals and drugs may be biopharmaceutically beneficial to improve solubility and/or change drug release profile. This study is focused on the preparation and characterization of organoclay (vermiculite and/or bentonite) nanocomposite materials based on imidazole derivative metronidazole, which is antibiotic drug used predominantly for treatment of intestinal and periodontal diseases. The structure of prepared samples was characterized by the X-ray diffractometry (XRD) and infrared spectroscopy (FTIR). Furthermore, the content of organic carbon was determined in the nanocomposite samples by multiphase carbon and hydrogen/moisture analyzer. Antimicrobial activity of nanocomposites was tested against bacterial strains S. aureus, E. faecalis, P. aeruginosa and E. coli, and it was evaluated by finding minimum inhibitory concentration (MIC). It was found that antibacterial activity depends on pH and also on clay matrix.