Making sustainable medical devices: five top tips

The lateral flow test market is a large and growing faction of the overall diagnostics market, worth an estimated $6bn in 2018, and is projected to reach $8.7bn in 2023. More than two billion lateral flow assays are produced each year, but with most tests being single-use and non-recyclable, as well as packaged within plastic, the leftover refuse is typically incinerated or sent to landfill.

Sona Nanotech is a Canadian life sciences firm that produces unique gold nanorods for diagnostic test and medical applications. It spends a large amount of its time dealing with lateral flow tests, those which are designed to detect a certain element in a body of liquid, such as over the counter (OTC) pregnancy tests and insulin assays.

Sona Nanotech president and chief executive Darren Rowles says: “I strongly believe lateral flow test developers and manufacturers have a duty to reduce plastic waste by rethinking how they make tests. Multiplexing – having more than one test line on a strip or more than one test in a cartridge – offers one solution. In many scenarios, from human and animal health to environmental and food testing, multiplexed tests negate the need for many separate individual tests.”

At present, multiplex assays are far more common in research settings than clinical ones. A drive amongst clinical manufacturers to multiplex as many lateral flow diagnostic tests as feasible could significantly increase both sustainability and efficiency, by allowing practitioners to test for multiple causes of a condition through just one process.

According to the UK Government, plastic waste in the oceans is set to treble within the next decade. Everyday single-use plastics can take over 400 years to biodegrade, which is why it’s so important medical device manufacturers look into using sustainable materials in their equipment.

Rowles says: “We must look at different materials, such as reusable plastic cartridges, or even paper or plant-based recyclable housings.”

American start-up Lia recently made headlines for producing the world’s first flushable pregnancy test, which is made up of the same natural plant fibres as toilet paper and breaks down when flushed. It still works in just the same way as a traditional OTC pregnancy test, looking for the presence of Human Chorionic Gonadotropin (hCG) and showing one line for a negative result and two for a positive one. If binned instead of flushed, Lia still biodegrades entirely within ten weeks.

Research is also burgeoning around renewable polyethylene (PR) and polyethylene terephthalate (PET), as these materials are easily recyclable.

Origin is a healthcare packaging solutions designer which offers a range of packaging solutions for the unique needs of the medical market, who make tablet packaging, dropper bottles and ready-to-use vials out of these plastics.

Origin’s head of new product development & innovation Jon Lant says: “Converting PET waste back into virgin grade material for use works by taking non-recycled PET waste — like coloured bottles — and breaking it down to base molecule level, while separating the colour and other contaminants.

“The molecules are converted back into PET, which is equal to virgin grade quality. The technology has successfully passed its pilot stage and is now moving towards testing at an industrial scale.”

It’s not just a final product which should aim to be eco-friendly – the production process should also seek to be as sustainable as possible.

Lant says: “The right design and manufacturing processes can significantly reduce waste and reliance on energy, creating a final product with a lower carbon footprint. As a heavily regulated industry we are not always the best at collaboration, yet there is barely an industry not affected by the cry for alternative materials, so it’s important to focus on developing solutions.”

He gives the example of 3D printing as significantly cutting back on waste during the R&D stages of development. This is because 3D printers gradually add material to the final item until it is complete, whereas most other manufacturing methods are subtractive, taking away from source materials to create a product and generating a lot of waste.

Of course, not every medical device can be 3D printed in its final stage, but a lot more leeway is available with prototypes. 3D printing can help companies design several different moulds for their device, for example, in a way that can be manufactured quickly and economically. This rapidly cuts down the time and cost of bringing a product to market, meaning sustainable manufacturing can make business sense and ecological sense.

Many medical devices will simply have to be disposed of after to preserve patient safety. However, some pieces of equipment can be designed to be re-used after a process of disinfection between patients.

Devices like surgical forceps and endoscopes can be made in both reusable and single-use formats, and a focus amongst manufacturers to develop the former over the latter can significantly reduce the amount of waste healthcare providers will need to send to landfill.

However, it is worth taking note of the environmental cost of sterilisation.

A study in BioProcess International found the energy consumption of a stainless steel pharmaceutical powder handling machine, after factoring in cleaning and sterilisation, reached 8,018 megajoules (MJ) of energy. In contrast, the process of manufacturing and disposing of single-use powder handling devices reached 4,156MJ. This means that the disposable set up was ultimately better for the environment despite the resulting waste due to the sheer energy required to maintain the reusable system.

These factors will vary from device to device and process to process, and sterilising the reusable medical devices in day to day practice will use considerably less energy than machines involved in drug manufacturing. However, it’s worth manufacturers considering what the cost of sterilising their reusable devices will be and whether it outweighs the benefits of the waste reduction of single-use devices.

Of course, these pointers mean nothing if manufacturers don’t take them on board and look to enact real change in the industry.

Team Consulting is a medical device consultancy which advises multiple clients in the sector about a variety of issues, including sustainability.

Team Consulting’s head of medtech Ben Wicks says: “The challenge for these companies which already have a product on the market is overcoming the inertia required to implement the changes and perform any reverification which is required. Often the companies can’t be bothered to make any change, unless it yields very significant cost savings.”

Sustainable changes can’t all be made overnight, but an attitude change can. If development teams begin to foster an understanding of factors like the microbiology, chemistry and material science of a device, they can develop a smarter more eco-friendly end product.

Wicks says: “The trick here is to consider the function which is performed by each component of the product, including the packaging, and not simply follow design and manufacturing convention ‘because everyone always does it like this’.”