Table 4.

Novel formulations to treat viral pulmonary infections.

Formulation	Drugs	Mechanism of Action	Disease	Excipients	Comments	Reference
Polymeric nanoparticles	Remdesivir	Inhibition of RNA polymerase	COVID-19	PLGA PCL	Selective targeting to ACE2 membrane receptor and enhanced antiviral effect compared to free drug	[156]
Nanovesicles	Dexamethasone	Agonist of the glucocorticoid receptor	COVID-19	Nanovesicles were obtained from neutrophils from bone marrow of mice or rhesus macaques	Better outcome when the formulation was inhaled instead of injected. Improved targeting to macrophages.	[157]
Nanosuspension	Remdesivir	Inhibition of RNA polymerase	COVID-19	PCL Pluronic® F127 HA Mannitol	Enhanced drug release compared to free drug (1.5-fold increase at 24 h and 1.9-fold increase at 48 h) and better safety index (1.3-fold higher).	[158]
Dendritic nanocarriers	Remdesivir	Inhibition of RNA polymerase	COVID-19	Hyperbranched G4-PEG6k-OH	First-order release kinetics with total release of remdesivir after 24 h and similar toxicity profile than free drug.	[159]
Nanostructured lipid carriers	Hydroxychloroquine	Inhibition of TLR9	COVID-19	Sweet almond oil Glyceryl behenate PC Gelucire®	Improved lung tissue targeting of hydroxychloroquine, but further investigation needed to confirm its potential for COVID-19 treatment	[160]
Nanoparticles	Resveratrol	Activation of Sirt-1	Infection caused by RSV	Unspecified	In vivo models demonstrated extended lung residence and reduced viral load compared to free drug	[161]
Liposomes	Oxymatrine	Antiviral activity induced by promoting difference cytokines	Infection caused by RSV	DPPC HSPC DPPG Cholesterol DSPE-PEG Chitosan	Selective distribution and improved retention in lung tissue compared to the free drug	[162]
Lipid nanoparticles	IFN-λ	Recruitment of neutrophils and NK cells	Influenza	Protamine Unspecified lipids Unspecified proteins	Improved delivery of IFN-λ to lungs and superior efficacy compared to recombinant IFN	[163]

Key: coronavirus disease 2019 (COVID-19); poly(lactic-co-glycolic) acid (PLGA); polycaprolactone (PCL); angiotensin-converting enzyme 2 (ACE2); hyaluronic acid (HA); toll-like receptor (TLR); phosphatidylcholine (PC); sirtuin-1 (Sirt-1); respiratory syncytial virus (RSV); interferon-λ (IFN-λ); natural killer cells (NK); dipalmitoylphosphatidylcholine (DPPC); hydrogenated soybean phosphatidylcoline (HSPC); dipalmitoylphosphatidylglycerol (DPPG); 1,2-distearoyl-sn-glycero-3phosphoethanolamine-N-[amino(polyethylene glycol)] (DSPE-PEG).