Eco-friendly Inhalers and New Propellants in the Pharmaceutical Industry

Abstract

The pharmaceutical industry is undergoing a major transition toward environmentally sustainable drug-delivery systems, particularly in the field of inhalation therapy. Conventional pressurized metered-dose inhalers (pMDIs) widely use hydrofluoroalkane (HFA) propellants such as HFA-134a and HFA-227ea, which, although ozone-safe, possess high global warming potential (GWP). Growing environmental concerns, regulatory pressures, and global climate commitments are accelerating the development of eco-friendly inhalers utilizing low-GWP propellants and alternative delivery technologies. Recent innovations include the introduction of hydrofluoroolefin (HFO)-based propellants, such as HFO-1234ze(E), which significantly reduce carbon footprint while maintaining therapeutic efficiency. In parallel, dry powder inhalers (DPIs) and soft mist inhalers (SMIs) are gaining prominence due to their propellant-free or low-emission design. Advances in formulation science, device engineering, and life-cycle assessment have further improved dose uniformity, patient compliance, and environmental sustainability. This paper reviews the environmental impact of traditional inhaler systems, explores emerging green propellant technologies, and discusses regulatory, technical, and economic challenges associated with their adoption. The transition toward eco-friendly inhalers represents a critical step in aligning respiratory drug delivery with global sustainability goals while ensuring patient safety and therapeutic efficacy.