S60 A new medical propellant HFO-1234ze(E): reducing the environmental impact of inhaled medicines

Abstract

<h3>Introduction and Objectives</h3> Pressurised metered dose inhalers (pMDIs) are an essential device option for patients with respiratory disease. However, due to the climate emergency, they face increased scrutiny due to the high global warming potential (GWP) of the propellant. Transition to pMDIs with next generation propellants (NGP) with a significantly lower GWP can provide a solution to support healthcare systems meet their carbon targets. In this work we show the reduction in greenhouse gas (GHG) emissions i.e. carbon footprint of a triple therapy pMDI with budesonide/glycopyrronium/formoterol fumarate dihydrate (BGF) realised by substituting the current propellant (HFA-134a) with candidate options HFA-152a or HFO-1234ze(E). <h3>Methods</h3> Cradle to grave life cycle inventory assessments of GHG emissions for this therapy were made using three propellants (HFA-134a, HFA-152a and HFO-1234ze(E)) aligned with ISO standards 14040 and 14044. GHG data were third party assured and considered variations resulting from the country of use, patient behaviour and disposal. In addition, four other key environmental impacts were quantified (freshwater use and ecotoxicity, resource and ozone depletion) and a comprehensive review was completed to understand the fate and effects of the candidate propellants and any transformation products to ensure holistic environmental due diligence. <h3>Results</h3> Substitution of HFA-134a with the selected NGP HFO-1234ze(E) would reduce the GWP of the propellant by &gt;99% resulting in a GHG emissions reduction for the whole pMDI device of at least 85%. Furthermore, other environmental impacts are reduced and the atmospheric transformation products are not of concern. <h3>Conclusions</h3> A pMDI using HFO-1234ze(E) would have GHG emissions typical of a dry powder inhaler (DPI) on a per dose basis. A change to a new propellant requires substantial investment, safety and clinical studies as well as regulatory approvals. Consequently, we estimate to transition to the new propellant in a portfolio of pMDI products across all markets, will take at least 5 years after the first product launch. However, a next generation of pMDIs with near-zero GWP propellant offers a way to resolve the climate and other environmental impacts posed by these devices without restricting patient choice or compromising clinical outcomes.