Macromolecules pulmonary drug delivery

One of the main drivers for the development of new pulmonary drug delivery systems has been the potential for noninvasive systemic delivery of protein and peptide compounds. The systemic delivery of macromolecules via the airways would overcome the inconvenience and cost associated with current methods of administration (injection), and appears likely given the large surface area of the airways and the thin pulmonary epithelium. Most research has concentrated on pulmonary delivery of insulin for the treatment of diabetes. Recently, one insulin product has completed phase three studies and is now undergoing review by European regulatory agencies for marketing approval. 

Although aerosols of various forms for treatment of respiratory disorders have been in use since the middle of the twentieth century, the interest in the use of pulmonary route for systemic drug delivery is recent. Interest in this approach has been further stimulated by the demonstration of potential utility of lung as a portal for entry of peptides and the feasibility of gene therapy for cystic fibrosis. It is important to understand the mechanism of macromolecule absorption by the lungs for an effective use of this route. 

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