The first pharmaceutical company to announce a low GWP HFC-152a metered dose inhaler (MDI) plans to introduce it by the end of 2025. HFC-152a will reduce the carbon footprint of the MDI by 90% to a level similar to a dry powder inhaler (DPI). The HFCs currently used in MDIs are mainly HFC-134a with <10% HFC-227ea. An investment of €350 million by the pharmaceutical company will be made to bring the new formulation to the market. The company will work jointly with the HFC-152a supplier to finalise the toxicology package demanded by worldwide regulatory agencies, prior to entering the next stage of clinical testing as required for any new drug. MDIs are one of a range of therapeutic options used to treat asthma and chronic obstructive pulmonary disease (COPD).
and manufacturer’s information
GWP values: The F-Gas AR4 GWP values are 124 (HFC-152a), 1430 (HFC-134a) and 3220 (HFC-227ea). The AR5 GWP values are 138 (HFC-152a), 1300 (HFC-134a) and 3350 (HFC-227ea).
Time to bring to new propellant MDIs to market: From Medical and Chemical Technical Options Committee 2018 Assessment Report– “MDIs are subject to extensive regulation by national health authorities to ensure product safety, product efficacy and product quality. The process for developing HFC MDIs [the HFC-134a MDIs] was therefore essentially identical to the development of a wholly new drug product, involving full safety testing, stability testing and clinical trials for each reformulated MDI. Research and development for a new product is a lengthy, challenging, costly and resource-intensive process.”
A range of therapeutic options: From Medical and Chemical Technical Options Committee 2018 Assessment Report- “It is important to note that MDIs, DPIs and other delivery systems all play an important role in the treatment of asthma and COPD, and no single delivery system is considered universally acceptable for all patients. Similarly, not all active ingredients are available equally as either an MDI or DPI. Healthcare professionals continue to consider that a range of therapeutic options is important. Any consideration of policy measures to minimise the environmental impact and carbon footprint of inhaled therapy should carefully assess patient health implications with the goals of ensuring patient health and maintaining a range of therapeutic options, as well as assessing economic implications. Each country has its own unique and complex makeup in terms of availability of medicines, overarching health care systems, and patient preferences.”
See also the EFCTC Fluorocarbons applications webpage for MDIs (Last update: January 2020)