Solstice Advanced Materials outlines its perspective on the transition to lowGWP propellants in an interview with International Pharmaceutical Industry Journal, focusing on regulatory change, manufacturing challenges, and sustainability in respiratory medicine.
How would you describe Solstice Advanced Materials’ role in the global transition toward low-GWP potential propellants for inhalers?
Solstice’s role is to help the pharmaceutical industry deliver on two priorities simultaneously. First, continued patient access to critical medications – the roughly 300 million people worldwide with asthma and Chronic Obstructive Pulmonary Disease (COPD) who depend on a pressurised metered-dose inhaler (pMDI) need that medication to remain available and effective. Second, environmental progress – pMDIs have historically been a significant contributor to healthcare’s carbon footprint due to the use of high-GWP propellants HFA-134a and HFA-227ea.
Solstice’s medical propellant HFO-1234ze(E), GMP is the world’s first low-GWP propellant in pMDIs approved for patient use in three countries and a region – UK, EU, AU and NZ. It has a GWP 99% less than hydrofluoroalkanes (HFAs). But our role isn’t simply to supply a propellant. The pharmaceutical companies reformulating today are taking on complex, multi-year programmes that touch formulation, valve compatibility, manufacturing readiness, and regulatory submission. Much of the technical ground-work for the transition is already in place, and we are now approaching a period where regulatory clarity is expected to drive a significant wave of product transitions. Our focus is on supporting early adopters in the transition with consistent supply, technical support, and product samples, while also planning for the broader industry adoption of low-GWP propellants.
Although there are other options such as dry powder inhalers (DPIs), why do pMDIs remain an essential part of respiratory care for many patients?
DPIs require patients to generate a strong, deep inhalation to draw medication into Figure 1: Greenhouse Gas (GHG) footprint comparison of DPIs to pMDIs with HFA and HFO-1234ze(E), GMP propellants the lungs, and that is a physical capability many patients simply don’t have. Young children, elderly patients, people in the acute phase of an asthma attack, and those with advanced COPD often cannot inhale forcefully enough for a DPI to deliver an effective dose.
In rescue and emergency situations, when a patient needs medication quickly and reliably, the pMDI remains the primary go-to solution. So, while substitution to DPIs is part of the conversation, it is not a universal solution. For a significant share of the roughly 300 million patients worldwide who live with asthma or severe COPD, the pMDI is irreplaceable. Additionally, the sustainability gap between DPIs and pMDIs is rapidly narrowing. With the introduction of Next Generation Propellants (NGPs), pMDIs are becoming capable of potentially delivering a lower carbon footprint than even DPIs (see Figure 1), while still maintaining the clinical advantages that many patients depend on.
