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The low global warming potential propellant HFA-152a does not induce bronchoconstriction or impair mucociliary
Michela Salvadori1, Dave Singh2, Kusum Mathews1
1Global Clinical Development, Chiesi Farmaceutici SpA, Parma, Italy.
Pulmonary Pharmacology & Therapeutics
|April 7, 2025
Summary
Replacing hydrofluorocarbon-134a (HFA-134a) with hydrofluorocarbon-152a (HFA-152a) in metered-dose inhalers is unlikely to cause bronchoconstriction or affect mucociliary clearance (MCC). This switch appears safe for asthma patients and healthy volunteers.
Area of Science:
- Pharmaceutical Sciences
- Respiratory Medicine
- Environmental Science
Background:
- Phase-down of high global warming potential propellants like HFA-134a in metered-dose inhalers necessitates alternatives.
- Hydrofluorocarbon-152a (HFA-152a) is a potential low global warming potential replacement propellant.
- Safety evaluation, including bronchoconstriction and mucociliary clearance (MCC), is crucial before adopting new propellants.
Purpose of the Study:
- To compare the bronchoconstriction potential of HFA-152a versus HFA-134a in adults with asthma.
- To assess the impact of HFA-152a compared to HFA-134a on mucociliary clearance (MCC) in healthy volunteers.
- To evaluate the safety profile of HFA-152a as an alternative propellant in metered-dose inhalers.
Main Methods:
- Bronchoconstriction study: Single-dose, randomized, double-blind, controlled, crossover trial in asthma patients (N=25). Primary endpoint: relative change in FEV1 at 15 min post-dose.
- Mucociliary clearance (MCC) study: Multiple-dose (8 days), randomized, open-label, controlled, crossover trial in healthy volunteers (N=20). Primary endpoint: percent particle retention at 2 and 4 hours.
- Both studies compared HFA-152a and HFA-134a, assessing treatment-emergent adverse events.
Main Results:
- Bronchoconstriction study: HFA-152a demonstrated equivalence to HFA-134a, with the 95% CI for FEV1 difference within the -10% to +10% limit.
- Mucociliary clearance (MCC) study: No significant difference was found between HFA-152a and HFA-134a for particle retention at 2 and 4 hours.
- Adverse events were mild to moderate, with no serious events reported in either study; similar proportions of participants experienced mild adverse events.
Conclusions:
- The findings suggest that substituting HFA-134a with HFA-152a in metered-dose inhalers is unlikely to induce bronchoconstriction in asthma patients.
- HFA-152a does not appear to impair lung mucociliary clearance (MCC) in healthy volunteers.
- The switch to HFA-152a as a propellant is not associated with significant safety concerns.
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