Introduction: Pulmonary route is one of the preferred routes for the administration of therapeutically active agents for systemic as well as localized delivery. Chronic obstructive pulmonary disease (COPD), bronchial asthma, pneumonia, pulmonary hypertension, bronchiolitis, lung cancer, and tuberculosis are the major chronic diseases associated with the pulmonary system. Knowledge about the affecting factors, namely, the etiology, pathophysiology, and the various barriers (mechanical, chemical, immunological, and behavioral) in pulmonary drug delivery is essential to develop an effective drug delivery system. Formulation strategies and mechanisms of particle deposition in the lungs also play an important role in designing a suitable delivery system.Areas covered: In the present paper, various drug delivery strategies, viz. nanoparticles, microparticles, liposomes, powders, and microemulsions have been discussed systematically, from a patent perspective.Expert opinion: Patent publications on formulation strategies have been instrumental in the evolution of new techniques and technologies for safe and effective treatment of pulmonary diseases. New delivery systems are required to be simple/reproducible/scalable/cost-effective scale for manufacturing ability and should be safe/effective/stable/controllable for meeting quality and regulatory compliance.
Keywords: Pulmonary route; drug delivery; patents; respiratory diseases.