Implications for Patient Experience: Comparison of Plume Characteristics from Pressurized Metered Dose Inhalers (pMDIs) Formulated with Hydrofluoroalkane (HFA) and Near-Zero Global Warming Potential Hydrofluoroolefin (HFO-1234ze

Lauren Mello¹, Glenn Collupy¹, Mark Sommerville¹, Libo Wu¹, Matthew Ferriter¹ & Kellisa Lachacz²

¹Global Product Development, AstraZeneca, Durham, 27703 United States

²Global Product Development, AstraZeneca, MöIndal, 431 83 Sweden

Summary

As part of AstraZeneca’s sustainability commitment, hydrofluoroalkane (HFA-134a) based metered dose inhalers (pMDIs), including Breztri Aerosphere®, are being reformulated with the near zero global warming potential (GWP) propellant HFO-1234ze. In-vitro and in-vivo bioequivalence of Breztri® formulated with HFA-134a (Breztri® HFA) and Breztri formulated with HFO-1234ze (Breztri® HFO) have been characterized to support the transition to the new low GWP propellant. To better understand the patient user experience, aerosol plume characteristics – such as plume force, velocity, and temperature – were compared across Breztri® HFA and Breztri® HFO as well as across other marketed pMDIs with varied compositions and device configurations. HFO-containing inhalers generated plumes with slightly lower plume force and higher temperature than HFA-containing analogues. These differences are attributed to propellant properties, excipients, and device designs. Overall, Breztri® HFO exhibits performance attributes and patient-perceived aerosol characteristics that are bracketed by other marketed pMDI products. The in vitro aerosol plume characteristics are supportive of patients’ adoption of products containing the low GWP propellant HFO-1234ze.