Two-Year Inhalation Studies in Mice and Rats With HFO-1234ze(E), a Near Zero Global Warming Potential Propellant for Use in Pressurized Metered Dose Inhalers

Paul Giffen, Matthew Jacobsen, James Cartwright, Rhiannon Hall, Natalie Waterhouse, Paul Carter, Jim Saul, Lindsay Wright, Per Aberg, Stefan Platz, Safety Sciences, Clinical Pharmacology and Safety Sciences, Regulatory Science Associates, Safety Sciences, Clinical Pharmacology and Safety Sciences, Safety Sciences, Clinical Pharmacology and Safety Sciences, Safety Sciences, Clinical Pharmacology and Safety Sciences

International Journal of Toxicology

Published online on October 28, 2025

Abstract

International Journal of Toxicology, Volume 45, Issue 3, Page 247-257, May-June 2026.
HFO-1234ze(E) is being developed as a next-generation propellant (excipient), with near zero global warming potential, for use in pressurized metered dose inhalers. In accordance with regulatory guidance, an assessment of the carcinogenic potential of HFO-...