Targeted drug delivery to the virus-infected airway; complications and remedies

Drug delivery to the airway and lower respiratory tract by aerosol inhalation has become a successful, non-invasive method of preventing and treating local disease of the lung. Consequently, it has been a promising route for clinical trials using highly specific and novel therapies to overcome viral pulmonary infection such as RNA interference, neutralising monoclonal antibodies and microparticle treatments. Yet despite this great potential, this form of delivery has proven somewhat ineffective due to airway remodeling, inflammation and mucus hypersecretion that results from viral symptoms in the respiratory tract. Here we review the research into the delivery technologies available as well as the types of therapeutics used for respiratory virus disease and examine how virus infection-induced airway inflammation modulates its success. We discuss the future of aerosol administration and present potential alternative methods for efficient drug delivery so as to improve postinfection virus control therapies.