EVALUATION OF A LIPOSOME SYSTEM FOR THE DELIVERY OF DESFERRIOXAMINE TO LUNGS IN RATS

Liposomes with various lipid composition and sizes, prepared by two di fferent techniques were evaluated for their potential to deliver desfe rrioxamine to lungs as a treatment against oxidative lung damage. Mult ilamellar vesicles (MLV) and reverse evaporation vesicles were prepare d out of a lipid mixture containing dipalmitoyl phosphatidylcholine, s tearyl amine, cholesterol and vitamin E. The administration of desferr ioxamine-encapsulated liposomes to rats by the intravenous route at a dose of 100 mg kg(-1), significantly prolonged the presence of desferr ioxamine in all the tested organs when compared with the administratio n of free desferrioxamine. The injection of reverse evaporation vesicl es extruded through a 2 mu m polycarbonate membrane exhibited a longer residence time of the desferrioxamine and of liposomal vitamin E in l ungs compared with the other types of liposomes tested. The examinatio n of liposome components in the bronchoalveolar lavage fluid (BALF) an d the alveolar macrophages recovered from BALF revealed that about 7 x 10(-3n)% of the administered desferrioxamine dose was recovered by th is technique at 3 and 17h after liposome administration. This high res idual concentration in the alveolar space confirms the hypothesis that liposomes can be delivered to the lung tissue when encapsulated in al veolar macrophages.