Montmorillonite nanodevices for the colon metronidazole delivery

The adsorption profiles of the antibiotic metronidazole (MNE) into the K10-montmorillonite (MMT-K10)clay and the subsequent release have been investigated as a function of pH and MNE/MMT-K10 ratio,in order to evaluate the potential of the MNE/MMT-K10 hybrids as controlled drug delivery system. Theadsorption mechanism has been first elucidated by performing complementary equilibrium and kineticstudies and through the X-ray diffractometry (XRD) characterization of the obtained composite materials.The gathered results allowed us to propose a mechanism consisting of a multi-step pathway involving theneutral and the cationic form of the drug, which interact with different sites of the clay surfaces, i.e. theinterlayer region and the faces of the lamella. In a second step the drug release kinetics has been studiedunder physiological pH mimicking conditions simulating the oral drug administration and delivery. Forthe sake of comparison the commercial formulation has also been employed for the release studies. Theinvestigation of the release profiles and the comparison with the commercial formulation of the drugreveal that the new-tailor made formulation could be fruitful exploited for successfully prolonged theaction of drug in the desired site.