ABSTRACT
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It is expected that the use of nanoparticulate materials will be of high importance in future science and technology. There is increasing optimism that nanotechnology, as applied to medicine, will bring signi†cant advances in the treatment of disease. The administration of drugs directly into the respiratory tract has been used in a number of therapeutic areas. The †eld of aerosolized drug application includes treatment of lung diseases, like asthma, chronic obstructive pulmonary disease, cystic †brosis, and lung cancer (Hickey, 2004). Aerosol delivery has also expanded into the †eld of systemic drug delivery (Laube, 2005). The optimal target in the lungs for delivery of drugs to the systemic circulation is the alveolar region. For rapid delivery, alveolar drug administration has a number of advantages including large absorptive surface area, easy permeability of the alveolar walls resulting in the fast passage from the alveolar airspace to the pulmonary capillary bed, and a direct connection between the pulmonary circulation and the systemic circulation. Aerosol delivery is much more ef†cient than the peroral administration because of low oral bioavailability for some drugs such as zanamivir (Fenton et al., 1977) or amantadine hydrochloride (Skyler, 2007). In the case of systemic targeting, the advantages of aerosol delivery with respect to peroral treatment include the possibility of avoiding losses in the gastrointestinal tract as well as metabolic destruction in the liver. In contrast to injection therapy, inhalation therapy is noninvasive, and so it is a more convenient and safe route leading to an improved treatment outcome. On the other hand, the aerosol treatment has no limitations for the use of water-insoluble drugs giving evident advantage with respect to injection therapy. Approximately one third of the modern drugs are water-insoluble or poorly water-soluble. Many currently available injectable formulations of such drugs can cause side effects that originate from the detergents and other agents used for their solubilization. Besides, water-solubility problems delay or completely block the development of many new drugs and other biologically useful compounds. Thus, the lung deposition route can be a good alternative for the administration of poorly soluble substances.
