Sustainability is something that needs to be considered in all industries and medtech is no exception. Here, inhalers are coming into the sustainability spotlight and for good reason. Metered dose inhalers (MDIs) alone account for around 3.5% of the UK National Health Service’s total carbon footprint and have been tagged as a carbon hotspot. Inhalers are indispensable for millions of people worldwide and tackling their impact will be a formidable task.

Many leading clinicians voice concerns about basing treatment choice on anything other than efficacy of treatment, but there is no reason that sustainability has to come at the cost of clinical benefit. It is more important than ever for sustainability to be factored into the design of our medical devices and that includes inhalers. The NHS is alive to this imperative and spells out its commitment in a health and environment appendix to the NHS Long Term Plan. A shift to lower carbon inhalers will, it says, reduce the footprint of health and social care by 4%.

Read Karen Unterman's blog on Designing a sustainable patient experience

When talking about inhalers the common target is the MDI. This is principally due to the hydrofluorocarbon (HFC) propellant gasses with high global warming (GWP) potential. Encouragingly, moves are already afoot to combat the HFC problem in MDIs. AstraZeneca, for example, has committed the 2025 launch of its next-generation pressurised metered dose inhaler (pMDI) with near-zero GWP. Chiesi, meanwhile, has its own five-year plan to reduce the carbon footprint of pMDIs by 90%. Dry Powder Inhalers (DPIs), which typically include around 20 plastic parts, will soon start to come under similar criticism to the metered dose devices.

I believe that sustainability is the responsibility of everyone in the development cycle – from drug developers to the supply chain, energy producers and product developers. At Cambridge Consultants we are already factoring it into the design phase, but it is clear to me that a more unified approach pinned to a clear roadmap is required to drive fundamental change and essential progress. This can and should be applicable to all inhaler types.

Assessing sustainability

Part of the difficulty we face arises from the large number of different methods for assessing sustainability. There are standard metrics such as GWP, mass of CO2 emitted, CO2 equivalent produced and many more. My colleagues and I have used life cycle analysis (LCA) to compare the impact of different design concepts. This is a useful approach when the ambition is to minimise the impact of a design and when comparing the benefits of different designs. This is an industry wide approach and was adopted by the Carbon Trust when comparing different GSK inhalers. Further, it’s a tool that can empower product developers when a joined-up approach to measuring the sustainability of a device is required. Using standardised tools and metrics would be a great place for the industry to start when focussing on sustainable product development.

When it comes to designing a product, there are a number of routes that can be explored to maximise the sustainability of the device. One is to reduce plastic through intelligent design and careful analysis to reduce the weight of plastic parts and reduce their number. This will lessen the amount of plastic and, in turn, the environmental cost of processing and manufacture. The aim should be to cut part numbers and plastic weight as far as possible. This can be effective and lead to more sustainable products such as Hovione Technology’s Papillon inhaler which is a single moulded part.

A second option could be to improve the lifetime of existing devices. Success here has implications for the number of products that need to be manufactured. A reloadable device with a large proportion of material retained for long periods would reduce the carbon footprint per dose. An example is the Respimat device, with a reloadable option that results in 1.2 million fewer inhalers being disposed in the UK each year and a 71% reduction of the carbon footprint of the product.

Both reducing the amount of plastic in each device and extending the life of devices would have a big impact on their overall carbon footprint. Standardised device targets in these areas could help to drive development in the sustainable direction.

Recycled plastics

Currently it is common to use a wide variety of plastics in each device. We can change the types of plastics that are used, but a big problem is that inhalers are medical products and so require plastics that meet the regulatory requirements. This currently precludes the use of recycled plastics or non-approved bioplastics. Here, we have to make a trade-off between mechanical properties and sustainability but there may be applications where novel materials are appropriate.

This is something that is starting to appear in other areas of medtech such as the zero carbon autoinjector developed by Ypsomed. There are few, if any, bioplastics which are approved to relevant medical standards, although many are food contact safe. However, plenty of promising materials are emerging, such as LATIGEA and the Biotec Bioplast range. If these materials and recycled plastics can be approved for medical device use, then it would be a big step towards developing more sustainable inhalers.

Packaging is another area that should be focused on, both in terms of device and drug packaging. Can we do anything here? With many DPIs the drug packaging is made up of an aluminium blister strip. Aluminium forming is very energy intensive and so a move to a recycled material could pay dividends. In addition to this device packaging could be an area where the more sustainable plastics are a feasible option.

As well as design, a key area of focus has to be on the end of life of the devices. Effective recycling schemes would have significant implications for the sustainability of inhalers. This has been attempted with schemes such as Teva, partnering with Teracycle, and the recently cancelled GSK Complete the Cycle scheme. Whilst these schemes exist, uptake is still low. During the nine year scheme, over two million inhalers have been recycled, saving the equivalent amount of CO2 emissions that are produced by over 8,500 family cars in one year. GSK has stated that a wider focus is needed rather than a standalone scheme. Again, it appears an industry wide approach is required rather than independent efforts. Larger, universal schemes may result in increased take-up and lead to a larger sustainability impact.

With such a wide array of inhalers available, the choice of device will always be important. Efficacy is the priority of course, but it is still possible to make balanced decisions with any eye on carbon footprint. There are encouraging signs that efforts to widen choice are moving in the right direction. NICE, the National Institute for Health and Care Excellence, is encouraging use of ‘greener asthma inhalers’ with its patient decision aid. Currently in the UK, 70% of inhalers prescribed are pMDIs with high GWP, yet in Sweden this number is only 10%. Can the UK move in the same direction as other countries?

An area where the debate of efficacy and usability over sustainability is prevalent is the development of connected inhalers – something that Cambridge Consultants specialises in. These connected devices help to improve patient adherence and technique, but those benefits can come at the cost of sustainability. For example, the batteries required often have a much bigger sustainability impact than all other elements of the design. There’s plenty of room for improvement here, and design choices such as rechargeable detachable electronics modules will contribute significantly in this area.

Overall, I hope I’ve made clear that there are many potential areas in the drug delivery market – and specifically with inhalers – where sustainable improvements can be made. As device developers there are many choices that we can make that will have a meaningful impact. I contend that a roadmap is vital to develop a unified, industry-wide approach to help device developers prioritise the most important product requirements and to set realistic sustainability targets. It would be great to hear your views, so please email me if you’d like to discuss the topic.


Image: Wikimedia 

Henry Blower
Senior Mechanical Engineer

Henry is a senior engineer within our medical technology department and has contributed his skills to the development of a number of innovative medical devices and inhalers. A specialist in mechanical design, Henry has a passion for sustainability and is intent on making sure it becomes more of a focus in his field.