INVESTIGADORES
AVENA Marcelo Javier
congresos y reuniones científicas
Título:
Some applications of clay minerals from the argentinean norpatagonia in human and veterinary medicine
Autor/es:
PAROLO, M.E.; AVENA, M.J.; ZAJONKOVSKY, I.; VALLÉS, J.M.; BASCHINI, M.T.
Lugar:
Castelleta Marina, Italia
Reunión:
Congreso; XIV International Clay Conference; 2009
Institución organizadora:
Association Internationale pour l'Etude des Argiles
Resumen:
Clays are common ingredients in pharmaceutical products both as excipients and active substances. Smectites in particular have been the most commonly used raw materials, as they can retain large amounts of drug due to their high cation exchange capacity (Parolo et al, 2008). The use of antibiotics is a worldwide extended practice in human and veterinary medicine to treat diseases caused by microorganisms. Tetracyclines are a group of antibacterial agents commonly applied against gram-positive and gram-negative bacterias as well as anaerobics. The chemical properties of these compounds have been extensively studied. They have different groups of the molecule that can undergo protonation-deprotonation reactions and the possibility to adopt different ionic species depending on the pH of the aqueous solution. The aim of this work is to study the adsorption of two different TCs (tetracycline and minocycline) on a Norpatagonian montmorillonite and to evaluate the effects of pH on the antimicrobial activity of the prepared TC-montmorillonite complexes. Adsorption of tetracycline and minocycline on montmorillonte is highly dependent on pH. Adsorption is relatively high at low pH, where important electrostatic attraction takes place between the negatively charged montmorillonite and the prevailing positively charged species of TCs. Adsorption decreases by increasing pH. The complexes tetracyclines-montmorillonite showed good inhibition properties over the growth of E.coli measured by antibiogram susceptibility tests, whereas the natural montmorillonite sample did not showed any antibacterial activity. Accordingly to the results, the prepared complexes may be effectively used in the formulation of antibiotic delivery systems, enable to maintain effective levels of the drug during the treatment (Aguzzi et al, 2007).