PULMONARY DELIVERY OF LIPOSOMES

An overview of current data on pulmonary delivery of liposomes is prov ided, entailing fate of aerosols in the respiratory tract, physicochem ical characterization of liposome aerosols, their therapeutic applicat ions, pulmonary fate and kinetics, and pulmonary safety. Drugs that ha ve been investigated for pulmonary delivery via liposomes include anti cancer agents (ara-C), antimicrobials (enviroxime, amikacin, pentamidi ne), peptides (glutathione), enzymes (superoxide dismutase). antiasthm atic and antiallergic compounds (metaproterenol, salbutamol, cromolyn sodium, corticosteroids). Promising developments including pulmonary d elivery of immunomodulators, antiviral agents and gene constructs (cys tic fibrosis, alpha1-antitrypsin gene) are also discussed. Finally, pu lmonary deposition and kinetics of drugs delivered via liposome aeroso ls, and targeting strategies to deliver drugs selectively to infected or impaired phagocytic (alveolar macrophages) and nonphagocytic (epith elial) cells in the lung are outlined. Based on the data on therapeuti c efficacy and pulmonary safety currently available, we conclude that liposome aerosols may play an important future role in the therapy of pulmonary diseases including intracellular infections, immunologic dis orders, and gene defects.