The potential of chitosan for pulmonary drug delivery

The administration of drugs through the pulmonary route offers great advantages, but it also requires overcoming many challenges. There is a need to develop appropriate carriers to deliver active molecules to their desired sites in the lung for either a local or a systemic effect. The polysaccharide chitosan is a very promising material for this purpose, given its demonstrated properties of biodegradability, biocompatibility, mucoadhesivity and its ability to enhance macromolecule permeation. In this review, the potential of chitosan for the development of drug carriers for the lung will be discussed. The most important features that support its selection will be explained. Additionally, different approaches to increase its performance, especially its solubility, its permeation-enhancing properties and gene transfection efficiency will be presented. Special emphasis will be placed on information on different chitosan-based carriers, namely nanoparticles and microparticles, intended for pulmonary drug delivery.