ABSTRACT
Remdesivir dry powder for inhalation was previously developed using thin film freezing (TFF). A single dose 24 hour pharmacokinetic study in hamsters, a small animal model for SARS-CoV-2, demonstrated that pulmonary delivery of TFF remdesivir can achieve plasma remdesivir and GS-441524 levels higher than the reported EC50s of both remdesivir and GS441524 (in human epithelial cells) over 20 hours. The half life of GS4412524 following dry powder insufflation was about 7 hours, suggesting the dosing regimen would be twice daily administration. Although the remdesivir-Captisol (80/20 w/w) formulation showed faster and greater absorption of remdesivir and GS-4412524 in the lung, remdesivir-leucine (80/20 w/w) exhibited a greater Cmax with shorter Tmax and lower AUC of GS441524, indicating lower total drug exposure is required to achieve a high effective concentration against SAR-CoV-2. In conclusion, remdesivir dry powder for inhalation would be a promising alternative dosage form for the treatment of COVID-19 disease.