Abstract
The pulmonary route has gained significant attention as a drug delivery method, particularly for managing respiratory diseases. This approach provides several benefits, such as rapid therapeutic action, minimized systemic exposure, improved patient adherence, and the ability to deliver high drug concentrations directly to the lungs. Advances in inhalation devices, including pressurized metered-dose inhalers (pMDIs), dry powder inhalers (DPIs), and nebulizers, have established the pulmonary route as effective for administering both small-molecule drugs and complex biologics. Recent research has showcased the successful use of inhaled biologics such as monoclonal antibodies, nanobodies, and protein-based treatments in conditions like asthma, chronic obstructive pulmonary disease (COPD), pulmonary fibrosis, COVID-19, and respiratory syncytial virus (RSV). These treatments employ innovative mechanisms, such as muco-trapping and immune modulation, to optimize site-specific drug delivery and minimize systemic side effects. As technologies for pulmonary administration continue to evolve, they provide a non-invasive and highly promising platform for enhancing respiratory therapies and broadening the applications of biologics.