Encapsulation of vancomycin and gentamicin within cationic liposomes for inhibition of growth of Staphylococcus epidermidis.

Liposomes have been prepared from dipalmitoylphosphatidylcholine (DPPC), cholesterol (Chol) and dimethyldioctadecylammonium bromide (DDAB). The cationic vesicles adsorb to biofilms of the skin-associated bacteria Staphylococcus epidermidis, which have a negative charge. Encapsulation of the antibacterial drug vancomycin into such liposomes enhanced its activity relative to the free agent. The effectiveness of the preparation was dependent on the fluidity of the liposomal membrane and on the level of drug entrapment within the aqueous core of the vesicles. The aminoglycoside antibiotic gentamicin was also encapsulated within similar liposomes but was less effective, possibly due to its slow passage through the membrane. The liposomal vancomycin preparation has potential medical use in treating bacterial infections of foreign body biomedical devices (e.g. catheters), with either topical or intravenous administration.