Liposomes as a carrier for pulmonary delivery of peptides and proteins

Pulmonary delivery of macromolecules as aerosols is an attractive non-invasive way to replace frequent injections, since lung permits rapid absorption and onset of action due to its intrinsic properties. Especially, inhalation of peptides and proteins for treatment of local and systemic diseases has gained more and more focusing after the commercialization of Exubera (R), a DPI formulation of insulin. However, there still exist problems such as short-action, systemic side effects, weak stability when applying aerosols for peptides and proteins. Encapsulation of peptides and protein drugs into liposomal carriers may overcome these disadvantages by offering sustained release and enhancing their local retention time. In addition, liposomes show high compatibilities with pulmonary alveoli for similar lecithin content. A great number of achievements have been made in developing peptides and proteins liposomes aerosols for either topical or systemic application, thus, the aim of this paper is to sum up the developed formulations, novel devices, the newly progress in the in-vitro and in-vivo studies as well as to look at the prospects of clinical applications.