Aberrant mucus production and airway re-modelling are underlying pathologies of respiratory disease, and restoring mucociliary clearance is a key goal in developing new therapies for asthma, chronic obstructive pulmonary disease, and cystic fibrosis. Since pathogen-induced exacerbation of these diseases leads to hospitalization of the patient and can promote disease progression over time, the use of antibiotics and antivirals may result in the prevention or reduction in duration of the exacerbation. However, airway mucus may also act as a potential barrier for inhaled therapeutics. A collaboration between the Respiratory and Infectious Disease groups at NIBR aims to address the scientific question of how mucus may affect the delivery of inhaled therapeutics. We seek to determine the relationship between airway mucus production and penetration of inhaled therapeutics and establish pharmacokinetic/pharmacodynamic relationships.