Evaluation of a liposome system for the delivery of desferrioxamine to lungs in rats.

Liposomes with various lipid composition and sizes, prepared by two different techniques were evaluated for their potential to deliver desferrioxamine to lungs as a treatment against oxidative lung damage. Multilamellar vesicles (MLV) and reverse evaporation vesicles were prepared out of a lipid mixture containing dipalmitoyl phosphatidylcholine, stearyl amine, cholesterol and vitamin E. The administration of desferrioxamine-encapsulated liposomes to rats by the intravenous route at a dose of 100 mg kg-1, significantly prolonged the presence of desferrioxamine in all the tested organs when compared with the administration of free desferrioxamine. The injection of reverse evaporation vesicles extruded through a 2 microns polycarbonate membrane exhibited a longer residence time of the desferrioxamine and of liposomal vitamin E in lungs compared with the other types of liposomes tested. The examination of liposome components in the bronchoalveolar lavage fluid (BALF) and the alveolar macrophages recovered from BALF revealed that about 7 x 10(-3)% of the administered desferrioxamine dose was recovered by this technique at 3 and 17 h after liposome administration. This high residual concentration in the alveolar space confirms the hypothesis that liposomes can be delivered to the lung tissue when encapsulated in alveolar macrophages.