In my role as Head of ESG at Bespak, the question I return to most often is a deceptively simple one: what does it actually take to lead on sustainability? Setting targets and making commitments are just the starting points. The harder work — and the real challenges — are building the capability, systems, skills, and accountability needed to deliver against them. The decarbonisation of pressurised Metered Dose Inhalers (pMDIs) is where leading on sustainability becomes most urgent for the inhalation sector. What was, until recently, a discussion framed largely by environmental targets is now governed by something more exacting: how can the sector substitute propellant systems at global scale without introducing clinical, regulatory or manufacturing instability?
For companies working at the drug–device interface, including Bespak, this shift reframes sustainability from a target-setting discussion into a technical and operational challenge. The challenge is not to declare intent, but to execute through the redesign of the validated systems — valves, elastomers, coatings, fill and finish processes and analytical methods — around propellants with materially different physicochemical behaviour.
Sustainability is becoming a design parameter
One of the most significant shifts I’ve observed is methodological. Sustainability data is moving upstream into product development rather than being assessed retrospectively. Sustainability data is used during design and development to guide decisions on materials, processes, and suppliers before a product is made. Rather than asking, “How sustainable is this product?” at the end, the focus shifts to: “How do we design this product to be sustainable from the outset?”
Lifecycle carbon modelling now informs actuator mass optimisation, polymer selection and recyclability potential, packaging configuration, and energy intensity of assembly processes. In effect, environmental performance is treated as a design parameter alongside reliability and cost and that changes how development decisions get made from the start.
This integration of ESG thinking into engineering decisions is what distinguishes real progress from reporting. It moves sustainability out of the report and into how products are designed, built, and delivered.
Below, I dive deeper into what that looks like in practice, across propellant chemistry, component design, manufacturing, supply chains, and ultimately, patient care.
The patient dimension is non-negotiable
Before getting into the technical detail, it’s worth being clear about what grounds all of it. Respiratory medicines are not discretionary — they are essential to patient care. This where the decarbonisation challenge becomes more complex than it first appears. Any transition must maintain clinical familiarity, usability and availability for often elderly or vulnerable patients. Human-factors equivalence, device ergonomics, and dose assurance therefore remain central validation criteria throughout. The industry’s credibility depends on ensuring that environmental gains do not introduce therapeutic risk or adherence barriers. This is the constraint within which all sustainability ambition must operate.
Why the transition is harder than it looks
Low GWP propellants cannot be treated as drop-in substitutes for those currently in use. Differences in vapour pressure, density, solvency, and material compatibility alter aerosolisation dynamics and drug–device interactions. These changes propagate across metering chamber accuracy, valve sealing performance, extractables and leachable profiles, plume geometry and particle size distribution, and long-term stability under varied storage conditions.
As a result, each parameter must be re-characterised under regulatory scrutiny equivalent to that applied to a new combination product. This extends development timelines, increases capital requirements, and introduces execution risk across manufacturing and supply chains.
In this respect, the transition resembles a platform redesign rather than a reformulation exercise — with implications for scalability, cost, and, critically, continuity of patient access.
Regulators are raising the bar — and rightly so
International environmental agreements established the direction of travel, but health authorities ultimately determine the cadence of change. Regulators must balance two priorities that can appear in tension: reducing lifecycle carbon emissions while ensuring uninterrupted access to essential respiratory medicines.
In practice, this realigns expectations. Manufacturers must now demonstrate therapeutic equivalence to legacy products, reproducibility at commercial scale, and carefully managed portfolio transition strategies not abrupt substitution.
This increases both the evidentiary burden and the execution risk, as progress is no longer driven by commitments alone, but by the ability to deliver under regulatory scrutiny.
As a result, technical readiness has become the pacing factor for adoption rather than the declaration of sustainability goals.
Component design has become the critical path
Historically, inhaler sustainability discussions centred on propellant chemistry. Experience now shows that device architecture is equally critical to environmental performance. Valves sit at the centre of this challenge governing dose metering, propellant compatibility, and durability. Their redesign requires deep expertise in elastomer–propellant interactions, surface energy effects, and micro-tolerance manufacturing — with direct implications for both emissions and patient outcomes.
From an ESG perspective, this marks a shift from single-variable solutions to systems thinking. engineering efforts now prioritise optimising geometries, stable material selection, and robust performance over real-world use cycles. At the same time, the lifecycle assessment increasingly informs these decisions early in development, linking component-level decisions to overall carbon impact.
Manufacturing strategy must evolve in parallel
Decarbonisation cannot rely solely on device innovation. It requires manufacturing systems capable of supporting legacy and next-generation propellant systems during transition. This introduces complexity across containment, process validation, workforce training and supply chains — but continuity of patient supply is non-negotiable. However, this is a resilience challenge as much as an environmental one: sustainable transition must not compromise access.
Cross-sector knowledge is accelerating solutions
Progress is being accelerated by applying capabilities from beyond pharmaceuticals. Computational fluid dynamics used in aerospace has improved predictive modelling of aerosol behaviour, reducing empirical iteration. Advanced tolerance analysis from precision manufacturing supports repeatability at the micro-mechanical level required to improve dosing consistency. Digital prototyping workflows reduce development timelines while limiting material waste. These approaches help reconcile sustainability objectives with the stringent validation culture of regulated medicine production, and they point to the value of looking beyond the industry’s own established frameworks when the challenge at hand is genuinely novel.
Supply chains are being re-regionalised
Environmental and resilience considerations are prompting a reassessment of geographically dispersed manufacturing models. Shorter, more integrated supply chains reduce transport emissions while improving resilience — an issue highlighted starkly by recent global disruptions. A more localised ecosystem for pMDI component manufacture also facilitates closer collaboration among formulation scientists, device engineers, and manufacturing teams, which is particularly valuable during the kind of iterative redesign the transition to low GWP propellants demands.
For ESG, this strengthens both environmental performance and operational resilience.
What will define leadership over the next decade
Organisations that navigate this transition successfully are likely to share three characteristics: integration of sustainability with product engineering rather than separating it into reporting structures; early investment in scalable, validated infrastructure before regulatory deadlines compel change; and the adoption of collaborative development models that share technical risk across the value chain.
The inhalation industry has entered a phase where progress will be measured less by ambition and more by the ability to deliver approved, manufacturable, lower-impact therapies at global scale. The goal is to develop treatments that are both clinically effective and environmentally better, and to deliver them reliably to patients everywhere, not just in limited trials or markets.
The decarbonisation of inhaled medicines is neither a branding exercise nor a singular technological breakthrough. It is an extended process of disciplined redesign — component by component, process by process — within one of healthcare’s most tightly regulated environments. Success will depend on close collaboration between pharmaceutical companies, device specialists, and regulators to deliver environmental progress without compromising the reliability patients depend on.
