Could you find exact dosage used in this study?
"Budesonide inhaled via dry powder inhaler, 400 micrograms per inhalation, 2 inhalations twice a day"--STerOids in COVID-19 Study(STOIC), catalogued at clinicaltrials.gov, study #NCT04416399.
I do not know much about inhalers, though, so I am assuming that the dosage is typically found in inhalers prescribed to asthmatics.