Relative bioavailability of budesonide/glycopyrrolate/formoterol fumarate triple therapy delivered using next generation propellants with low global warming potential

Introduction: The climate crisis poses an immediate threat to human health and well-being, demanding urgent adaptions across sectors, including healthcare. The development of pressurized metered dose inhalers (MDIs) with greater sensitivity to the climate emergency using novel propellants with lower global warming potentials (GWPs), but comparable pharmacokinetic (PK) parameters to currently marketed MDIs, is a vital step toward reducing the impact of healthcare for respiratory disorders on climate change. This study evaluated the relative bioavailabilities of the individual components of a fixed-dose combination of budesonide/glycopyrrolate/formoterol fumarate (BGF) 160/9/4.8 mu g per actuation between three different propellant formulations. Methods: Healthy male participants (aged 18-60 years) were randomized into a single-blind, three-period, single dose, single-center, crossover study (NCT04600505). The PK and safety and tolerability profiles of BGF MDI formulated with two novel propellants with low GWP (hydrofluoroolefin-1234ze [HFO]; hydrofluorocarbon152a [HFC]) were compared with BGF MDI formulated with the propellant used in the currently marketed reference product (hydrofluoroalkane-134a [HFA]). The study included a screening period, three treatment periods (with 3-to 7-day washout periods between each dose), and a follow-up. The primary PK parameters assessed were maximum observed plasma concentration (Cmax), area under the plasma concentration curve (AUC) from time zero extrapolated to infinity (AUCinf), and AUC from time zero to the time of the last quantifiable analyte concentration (AUClast). The study was not powered to statistically demonstrate bioequivalence. Results: Forty-seven participants completed the study, and 24 participants were evaluable for PK assessments. Systemic exposure, based on geometric mean ratios (90% confidence interval), to each BGF component from the test propellants delivered in a standard MDI was comparable with the reference propellant for AUClast (HFO vs. HFA: budesonide, 107.30 [94.53, 121.90]; glycopyrrolate, 106.10 [86.18, 130.60]; formoterol, 98.13 [86.44, 111.40]; HFC vs. HFA: budesonide, 98.80 [84.59, 115.40]; glycopyrrolate, 99.71 [80.84, 123.00]; formoterol, 107.00 [88.82, 128.90]); AUCinf (where evaluable) and Cmax followed the same trend. There were no serious adverse events or adverse events leading to treatment discontinuation. No new safety signals were observed. Conclusions: Systemic BGF component exposure was similar for both test propellants (HFO and HFC) compared with the HFA reference propellant, with an acceptable safety profile in the studied population. Therefore, both novel low GWP propellants show strong potential as candidates for development of MDIs with greater sensitivityto the climate crisis, a vital step toward ameliorating the detrimental impact of healthcare on the environment. Further investigation in larger studies is warranted.