Related Experiment Video
Updated: Jan 13, 2026
07:28
Dry Powder and Nebulized Aerosol Inhalation of Pharmaceuticals Delivered to Mice Using a Nose-only Exposure System
Published on: April 6, 2017
41.4K
Two-Year Inhalation Studies in Mice and Rats With HFO-1234ze(E), a Near Zero Global Warming Potential Propellant for
Paul Giffen1, Matthew Jacobsen1, James Cartwright1
1Safety Sciences, Clinical Pharmacology and Safety Sciences, R&D, AstraZeneca, Cambridge, UK.
International Journal of Toxicology
|October 28, 2025
Summary
Hydrofluoroolefin-1234ze(E) (HFO-1234ze(E)) was evaluated for carcinogenic potential in mice and rats. The studies found no evidence of carcinogenicity, supporting its use as a medical propellant.
Area of Science:
- Toxicology and Pharmacology
- Environmental Science and Chemistry
Background:
- Hydrofluoroolefin-1234ze(E) (HFO-1234ze(E)) is a next-generation propellant with near-zero global warming potential.
- Regulatory approval for HFO-1234ze(E) as a medical propellant requires assessment of its carcinogenic potential.
Purpose of the Study:
- To evaluate the carcinogenic potential of HFO-1234ze(E) following inhalation exposure in rodents.
- To provide data supporting the regulatory approval of HFO-1234ze(E) as an excipient in metered dose inhalers.
Main Methods:
- Two-year carcinogenicity studies were conducted in mice and rats via inhalation route.
- Animals were exposed to HFO-1234ze(E) at doses of 2132, 6218, 21,193 mg/kg/day (mice) and 379, 120.8, 3918 mg/kg/day (rats).
- Comprehensive assessments included in-life observations, organ weights, histopathology, and hematology.
Main Results:
- HFO-1234ze(E) was well tolerated across all tested doses in both species.
- No HFO-1234ze(E)-related adverse effects, including neoplastic or non-neoplastic findings, were observed.
- Hematology assessments showed no significant changes related to HFO-1234ze(E) exposure.
Conclusions:
- HFO-1234ze(E) demonstrated no carcinogenic potential in mice and rats under the study conditions.
- These findings support the safety of HFO-1234ze(E) for use as a medical propellant in pressurized metered dose inhalers.
Keywords:
HFO-1234ze(E)carcinogenicityinhaler propellantnon-clinicalpressurized metered dose inhaler (pMDI)trans-1,3,3,3-tetrafluoropropeneMore Related Videos
Related Concept Videos
01:23Inhaled Medications
728
Inhaled medications are crucial for managing chronic obstructive pulmonary disease (COPD) and asthma. They are essential for effective treatment and control, ensuring optimal respiratory health and well-being. Inhaled medication delivers drugs directly to the lungs, providing a rapid onset of action and reducing systemic side effects compared to oral or injectable medications. Three primary types of inhalation devices are used to administer these medications: nebulizers, metered-dose inhalers...
728
01:20Inhalational Anesthetics: Overview
976
Inhalation anesthetics are drugs that induce general anesthesia upon inhalation. They work by increasing the sensitivity of GABAA receptors or inhibiting NMDA receptors, leading to a decrease in central nervous system activity. The depth of anesthesia can be rapidly adjusted by changing the concentration of the inhaled gas. Some common examples of inhalational anesthetics include volatile liquids like isoflurane, desflurane, sevoflurane and gases like xenon and nitrous oxide. Isoflurane, a...
976