Bionanocomposites based on cationic and anionic layered clays as controlled release devices of amoxicillin

Abstract

In the present work bionanocomposite materials based on layered double hydroxide and montmorillonite clay as drug delivery system for oral administration were prepared. With this aim, amoxicillin, an antibiotic commonly indicated for diverse kind of infections, was intercalated into Mt. or LDH interlayer space through cationic exchange and reconstruction reactions, respectively, taking advantage of the possibility to obtain positively or negatively charge in amoxicillin structure, depending on the pH of synthesis. From the diverse physicochemical characterization techniques, i.e. XRD, FTIR, TG-DTA and SEM was possible to infer that amoxicillin molecules are disposed as monolayer, covering the interlayer surface of both solids, neutralizing the charge of the lamellae, and consequently, conferring an improve in the thermal stability of the drug. In order to improve the performance of these intercalation compounds in acid media, e.g. stomach fluid (pH 1.2), these clay-amoxicillin hybrids were incorporated in a biopolymer matrix composed by carboxymethylcellulose polysaccharide and zein protein, giving rise bionanocomposite beads. These bionanocomposite materials, which were evaluated as a function of the type of intercalation compound and the amount of zein protein, showed good compatibility between their components, offering a more controlled release of amoxicillin compared to the respective hybrid or pure biopolymers blend, allowing that the active specie reaches the intestinal tract, improving the bioavailability of the drug.