Liposomes as drug delivery system in the treatment of infectious diseases. Potential applications and clinical experience.

Liposomes are microscopic, closed lipid vesicles able to entrap hydrophilic as well as lipophilic compounds. They constitute a versatile drug delivery system. When injected by the intravenous route, liposomes are taken up by macrophages in the liver and in the spleen. Investigation of several animal models of infections has shown that liposome-entrapped anti-infectious drugs are active against infections due to facultative intracellular bacteria, parasites such as Leishmania, viruses such as the one causing Rift valley fever. Liposomes of different lipid compositions, structures and sizes were used for intravenous administration of anti-infectious drugs without inducing toxicity in the tested animals. Clinical experience was obtained with two different liposomal preparations of amphotericin B in the treatment of systemic fungal diseases in cancer patients; these preparations were shown to be effective and very well-tolerated.