Comparative Pharmacokinetics Study of the Leutragin Peptide Drug in Blood Serum and Lung Tissue in C57BL/6Y Mice after Single Inhalation Administration

This paper presents a study into the pharmacokinetics of a new inhaled anti-inflammatory hexapeptide, registered as “Leutragin”. This drug is used as a new treatment approach for viral pneumonias, whose severe course is directly related to the cytokine inflammatory cascade referred to as a cytokine storm. The study involved investigation of lung tissue and serum after a single inhalation administration of Leutragin to mice of the C57BL/6Y line at a dose of 150 mg/kg. The time required to reach the maximum concentration (Tmax) of Leutragin in serum and lung was 30 min and 10 min, respectively. The maximum concentration (Cmax) in lung was 358.5 ng/g, which exceeded the concentration maximum for blood (53.84 ng/g) by over six times. It was found that, after inhalation administration, Leutragin is rather rapidly eliminated from the body with the half-life of the drug (t1/2el) from blood serum and lungs ranging from 25.8 to 38.9 min.