Low GWP pMDI Q&A with Aptar’s ZEN30 Futurity™ Valve Solution

Transitioning to Lower GWP pMDIs with Aptar Pharma’s Chris Baron

This Q&A with Aptar Pharma’s Chris Baron, Director Business Development, discusses the benefits and challenges of transitioning to using lower global warming potential (GWP) propellant in pressurized metered dose inhalers (pMDIs). The interview also covers Aptar Pharma’s strategy to support its customers in their carbon emission reduction quest by developing the new ZEN30  Futurity™ metering valve.

Driving pMDI Propellant Change

The transition to low global warming potential (GWP) propellants in pressurized metered dose inhalers (pMDIs) is a critical step for pharmaceutical companies aiming to reduce their direct and indirect carbon emissions as well as their impact on the environment. Current hydrofluoroalkane (HFA) propellants, such as HFA134a and HFA227ea, have a high GWP of approximately 1,300, contributing significantly to CO2 emissions. With new EU F-Gas legislation (adopted March 2024) mandating a 15% reduction in F-gas emissions by 2027 and a complete phase-out of hydrofluorocarbons (HFCs) by 2050, alongside potential restrictions under REACH regulations, the industry is shifting toward low GWP propellants like HFA152a (Koura) and HFO1234ze (Honeywell). These propellants can reduce the CO2 footprint of pMDIs by over 90%, aligning with global climate goals while maintaining the efficacy of inhaled therapies.

Lower GWP pMDI Properties

Low GWP propellants differ from HFAs in properties such as flammability, density, vapor pressure, boiling point, and dipole moment, which affect formulation solubility and stability. HFA152a, for instance, is more flammable, necessitating specialized manufacturing suites compliant with ATEX safety guidelines.

Next Generation pMDIs for Lower GWP propellants

The new lower GWP propellants also require that the pMDI components, including the canister, actuator, and metering valve are evaluated for chemical compatibility and the ability to consistently delivery precise dosing over the product’s shelf life. Aptar Pharma has addressed these challenges by developing the ZEN30  Futurity™ metering valve, designed specifically for compatibility with HFA152a and HFO1234ze lower GWP propellants. The new ZEN30  Futurity™ metering valve was constructed using a variety of compatible materials like Cyclic Olefin Copolymer elastomer (CCOe) for gaskets, ethylene propylene diene monomer (EPDM) for dynamic elastomers, and polybutylene terephthalate (PBT) for other components to provide durability, and functionality.

Collaborative Approach to Reduce Carbon Emissions

Aptar Pharma’s engaged in collaborative efforts early on in the process, including participation in meetings with propellant manufacturers, pharmaceutical companies, regulators and material suppliers for a more efficient and unified approach.  Aptar supports customers not only with reliable global supply of fully optimized pMDI components, but also with specialized services development services. These include Nanopharm’s inhaled drug development expertise, access to ATEX-rated pilot filling facilities, and patient onboarding from their Noble patient onboarding and human use studies services.  These integrated efforts help Aptar Pharma’s customers to accelerate market entry for their new lower GWP pMDI products.

The Challenges of Transitioning to Lower GWP Propellants In pMDIs

The transition to using lower GWP propellants with pressurized metered dose inhalers is not without challenge. The selection of the pMDI component materials was the result of extensive testing, experimentation and modelling to arrive at a manufacturable, reliable and compliant design that achieved the critical quality attributes desired.  By maintaining the use of pMDIs to deliver the patient’s drug dosing, this minimizes the risk of patient compliance reductions or changes to the patient’s perceived ease of use. In addition, the pMDI filling and manufacturing processes must be upgraded to handle the new lower GWP propellants with their higher flammability. Aptar Pharma has also expanded the production of some critical elastomer materials in-house for increased quality control and reliability of supply.

The Future of Lower GWP pMDIs is Bright

For patients, the transition ensures continued access to convenient pMDI delivery, which is critical for chronic and rescue therapies. pMDIs represent a convenient and familiar way to deliver inhaled drug products without the complications presented by changing to new or alternative drug delivery methods. In the long term, the economics of the transition will be impacted by the rapidity of phasing out the older propellants, propellant supply changes, the availability of new, compatible pMDI components as well as regional regulation and taxes. Aptar’s ZEN30 Futurity™ valve positions pMDIs to remain a cost-effective, widely used delivery platform while significantly reducing carbon emissions, supporting both patient needs and global sustainability goals.