A supercritical assisted process for the production of amoxicillin loaded liposomes for anti-microbial applications

The most common limitations of drug carriers, such as liposomes, are low Encapsulation Efficiency (EE), poor biocompatibility and drug degradation. Several techniques have been developed to overcome these problems; among these, Supercritical assisted Liposome formation (SuperLip) is a CO2 mediated technique for the production of liposomes at nanometric level. SuperLip has been employed to produce amoxicillin loaded liposomes. Vesicles have been loaded with 1, 5, 10 and 20 % (w/w) amoxicillin to lipid ratio; then, 1 % (w/w) cholesterol/lipid was added to liposomes lamellae. Liposomes showed mean diameters of about 200 nm and EE up to 84 %. Anti-microbial effect of Amoxicillin-loaded liposomes on Escherichia coli was studied. The growth of E.coli was monitored inoculating bacteria in Luria-Bertani medium with different liposomes concentrations (25, 50, 100 ppm) and different antibiotic/lipid ratio (5, 10, 20 %). An increase in the amoxicillin/lipid ratio enhanced growth inhibition of E.coli, especially at 100 ppm.