Biocompatible biodegradable polymeric nanocarriers in dry powder inhalers (DPIs) for pulmonary inhalation delivery

Pulmonary drug delivery is an efficient way to deliver drugs directly to the site of action i.e., lungs or to the blood circulation with minimum systemic effects. Recent emergence of coronavirus disease-2019 (COVID-19) and expeditious development of nanoparticle-based vaccines have recently reignited considerable interest in designing inhalable nanoparticle-based drug delivery systems as next-generation respiratory therapeutics. In this review, dry powder inhaler (DPI) formulations based on polymeric nanoparticles have been reviewed. It comprehensively describes various biodegradable and biocompatible synthetic (e.g. polylactic-glycolic acid, polyethylene glycol, polyethylenimine, and polycaprolactone) and natural (e.g. alginate, chitosan, dextran, hyaluronic acid, and gelatin) polymers used in formulating nanoparticle-based dry powder inhalers. This review covers the most recent drugs encapsulated in synthetic-based and natural-based biocompatible nanocarriers used in DPIs, providing latest approaches for treating various respiratory and pulmonary disorders. DPIs comprised of biocompatible biodegradable polymeric nanocarriers exhibited favorable particle properties and aerodynamic properties. In addition, these polymeric nanocarriers are chemically versatile in being either synthetic or natural. This chemical versatility enables versatility in the various types of drugs that can be incorporated into DPIs provided that the needed particle properties and aerodynamic properties are maintained.