Study to Assess the Lung Exposure Bioequivalence of Budesonide, Glycopyrronium, and Formoterol Delivered by BGF MDI With Next-Generation Propellant Compared With BGF MDI With HFA Propellant

This is a Phase I, randomized, double-blind, single-dose, single-center, partial-replicate, 3 way cross-over study. The study will comprise: * Screening period: up to 28 days prior to first dosing; * Three treatment periods : Subject will be resident in the Clinical Unit from the morning on the day before dosing with BGF MDI (Day 1 of Treatment Period 1), until 24 hours following the final dose (Day 2 of Treatment Period 3 a washout period of 3 to 7 days between each dose; * Follow-up: Within 3 to 7 days after the last administration of BGF MDI. Subjects will receive 3 single-dose treatments of BGF MDI \[Test formulation Treatment A (BGF MDI HFO); Reference formulation Treatment B (BGF MDI HFA)\] on Day 1 of each Treatment Period (1, 2, and 3) following an overnight fast of at least 8 hours. There will be a washout period of 3 to 7 days between each dose. Each subjects will be involved in the study for up to 55 days.