Tag: Testing & Evaluation

||||||||||||||||
By Matt Morris and Dan Haworth
April 5th 2022
Find the authors
on LinkedIn:
Matt Morris

Matt Morris

Sustainability Leadu202f
Dan Haworth

Dan Haworth

Head of Diagnostics

Reducing the carbon footprint and plastic waste of LFTs: Evidence-based opportunities

Billions of lateral flow tests have been used worldwide during the COVID-19 pandemic – over two billion have been provided in the UK alone. Debate has raged on social media about why the tests need to use so much single-use plastic and how they could be made more ‘sustainable’. The test strip caseworks is a particular source of dismay – why so much plastic to house such a tiny test strip?

With the UK government ending the free distribution of lateral flow tests for the general public – citing a transition from emergency response to longer-term management of the pandemic – now is the ideal time to look more closely at the sustainability of these lateral flow tests, and to seek the data to demystify some of the emotional assumptions being made.

Familiarity with lateral flow testing has certainly increased, as has confidence in their clinical performance. It’s expected that lateral flow devices will be more present in our daily lives post-pandemic – not just for COVID-19 and pregnancy testing but to diagnose diseases such as seasonal influenza and sexually transmitted infections – all from the comfort of the home.

We’ve carried out a high-level assessment to quantify the approximate environmental impact of lateral flow tests and identify evidence-based suggestions for improving their environmental sustainability.

Why do COVID-19 lateral flow tests contain lots of single-use plastic in the first place?

The emergence of COVID-19 was a global emergency, and vast quantities of lateral flow tests were needed urgently. Once developers could produce the right immunoassay chemistry to detect the virus (SARS-CoV-2), it required implementation in a low-cost, low-risk device, that has a mature supply chain – with proven, readily available materials that wouldn’t compromise analytical or clinical performance.

This meant using existing plastic casework designs to retain and protect the nitrocellulose test strip. Plastic is robust, low cost, lightweight, easy to transport, and easily printed for QR codes and LOT numbers. Critically, it’s a consistent material proven for the highest volume manufacturing and won’t interfere with the immunoassay chemistry.

From a performance, cost, and manufacturing perspective, redesigning the product with new materials would have been high risk. Material changes may also have needed significant R&D costs, new capital equipment as well as additional cost and effort needed to demonstrate equivalence and achieve regulatory approval – risking the ability to provide sufficient numbers of high-quality tests, at speed during the pandemic.

Our results: The sustainability of lateral flow tests

But how serious an environmental impact do these tests have? To find out, we broke down a test into its constituent components and weighed them to calculate the approximate environmental impact, using standard emissions factors to calculate the carbon footprint of a single test.

web_body_lateral-flow-test-kit-1

We focused on carbon footprint (the carbon dioxide and other greenhouse gases emitted during manufacture, transport, and disposal of the tests) and plastic waste (waste that would persist indefinitely if released into the environment) – the two issues that have attracted the most attention around lateral flow tests. A more comprehensive study should consider a broader range of environmental impacts, for example, the use of scarce resources and emission of other pollutants to avoid unintended consequences of any product changes.

Our results reveal:

  • The components needed to conduct the test account for around half of the carbon footprint and around two-thirds of the plastic waste. Packaging makes up most of the rest – as is often the case, a surprisingly high proportion of the total environmental impact
  • The test strip caseworks, which attracts the most comment online, is responsible for around 30% of the carbon footprint and 40% of the plastic waste. While it’s the most significant single contributor to the environmental impacts we evaluated, the large number of other small parts is also significant. Focusing on the caseworks therefore might not be the best strategy for improving the sustainability of the tests overall.
web_body_lateral-flow-test-analysis-1a-2
web_body_lateral-flow-test-analysis-1b-3

Lateral flow tests a minor piece of UK healthcare’s environmental impact

To put these numbers into context, we can compare the environmental impact of the two billion COVID-19 lateral flow tests distributed in the UK with the UK healthcare system’s overall environmental impact. We estimate the UK’s lateral flow tests have a carbon footprint equivalent to around 0.5% of the total NHS carbon footprint. This isn’t a trivial amount, but it’s also not the largest single contributor to the impact of the UK health system.

It’s also worth considering the positive environmental impact of a user-administered test on the health system. Conducting a test at home can eliminate the need for an individual to visit a test site, GP’s surgery, or hospital (assuming the clinical performance of the lateral flow test is adequate). Based on estimates from the Sustainable Healthcare Coalition, one lateral flow test has around 5% of the carbon footprint of a single GP appointment and produces a similarly low percentage of non-degradable (plastic) waste.

And that’s before we consider travel. We estimate one lateral flow test has the same carbon footprint as driving 350 metres in an average UK car. So, if you’re driving yourself to a test site or GP surgery some distance away, at-home lateral flow tests compare even more favorably.

If a lateral flow test prevents an individual from transmitting COVID-19 to a vulnerable person, there’s a public health benefit – as well as an environmental benefit – to keeping people out of the hospital. We can all see the discarded waste from home tests, but the less visible impact from energy- and material-intensive medical interventions is often significantly higher.

These approximate figures demonstrate why building an evidence base is vital during product development targeting sustainability objectives – because the results can be unexpected and non-intuitive.

Quick ways to optimize today’s lateral flow tests

Just because waste from lateral flow tests might not be the most urgent sustainability issue for UK healthcare, that doesn’t mean we can’t and shouldn’t do something about it.

We used the ‘avoid/shift/improve’ model to find potential quick wins for lateral flow tests. These reduce the carbon footprint of each test by nearly a third and the plastic waste by almost a quarter – without impacting the fundamentals of how the test works.

They include:

  • Eliminate waste bags. There’s a case for quickly isolating contaminated waste (even given COVID-19 also spreads from infected individuals through the air), but the bags account for around 5% of the carbon footprint of the test. It’s not clear how widely used they are in a domestic setting – there may be a risk-based justification for not including them in the test kit.
  • Package all the test strips in a single foil pouch. Using a single re-sealable pouch to protect the tests from ambient humidity (rather than individually packing each test in a pouch with desiccant) is common in packs of lateral flow tests designed for use by healthcare professionals. However, once opened, the stability lifetime of the remaining tests is affected.
  • Reduce the size of paper instructions. These are important for the effectiveness of the tests and are a regulatory requirement, but account for 5% of the carbon footprint of a test – could they be reduced in size?
  • Eliminate the cardboard sleeve. This packaging isn’t essential to the safe and effective functioning of the test, and it seems likely that the functions it does provide could be achieved with less material.
  • Prefill the extraction tubes with buffer solution. This is already done in some test kits, although manufacturers need to be conscious of moisture loss and the effect on shelf life. However, the separate plastic vial used in the test kit we studied accounts for around 5% of the carbon footprint and plastic waste.
  • Increase the size of the pack from seven to ten tests. This would mean less package waste per individual test. Including ten tests in one pack instead of seven reduces the carbon footprint by around 5% (depending on how many other optimizations are done at the same time). Perhaps a pack of seven tests was originally designed to cover a week of daily testing – but is that how tests are being used in practice?
web_body_lateral-flow-test-analysis-2

Redesign of the test strip caseworks

Looking to the longer-term gets us into product redesign – creating a new generation of the product with sustainability in mind. Doing this can take significant investment since, for medical devices, it’s likely to require new regulatory approval, which is a lengthy and costly process.

A popular idea circulating for lateral flow tests is to minimize the plastic test strip caseworks (without compromising the essential functions of providing a stable platform, and protecting the nitrocellulose test strip). It might be possible to halve the caseworks mass and reduce the overall carbon footprint and plastic waste by 15-20%. This would require significant investment in R&D, production tooling, and regulatory approval hoops to jump through – but could be worthwhile if future demand for tests stays high.

Longer-term options

If we consider that the world may require billions more lateral flow tests over the coming decade, a more comprehensive redesign becomes commercially viable. This could involve stripping the design back to the fundamental requirements for a lateral flow test – flowing a sample through the test strip in a way that is controlled and free from contamination. Current designs take advantage of established components to collect, buffer, and dose the sample – but, at this production volume, it may be worthwhile designing a system from the ground up that is optimized for cost, usability, performance, and sustainability.

Sustainability as a brand differentiator

It’s clear there’s scope to optimize lateral flow tests to reduce their environmental impact – and a systematic analysis reveals options beyond those that might jump out to someone when they use the tests. But it’s essential to put the impact of lateral flow tests in the context of the wider healthcare system, to focus resources where they can have the most environmental impact – and to recognize that, sometimes, the plastic waste people can see helps to avoid more serious, but less visible consequences.

On the other hand, while visible plastic waste from lateral flow tests may not be the most pressing environmental issue facing the healthcare industry, it highlights the growing influence consumer opinion is likely to have as diagnosis and treatment shift from hospitals to homes. And as lateral flow tests become (in the UK, at least) a product people buy with their own money, choosing from a range of options, there may be a competitive advantage for businesses that take note and optimize their products for sustainability.

Featuring analysis conducted by Katie Williams, Mechanical Engineer

References
  • Prime Minister sets out plan for living with COVID [Internet]. GOV.UK. 2022 [cited 1 April 2022]. Available from: https://www.gov.uk/government/news/prime-minister-sets-out-plan-for-living-with-covid
  • The Sustainable Healthcare Coalition. Care Pathways Calculator. [Internet]. Sustainable Healthcare Coalition. 2022 [cited 1 April 2022]. Available from: https://shcoalition.org/
Pilot manufacture for drug delivery devices||
By Jon Powell
January 18th 2022
Find the authors
on LinkedIn:
Jon Powell

Jon Powell

Senior Consultant, Manufacturing

Prepare the way: Pilot manufacture for drug delivery devices

Bringing a drug delivery device to a clinical trial is a complex endeavor. You need to keep a handle on multiple moving parts, for example, the active pharmaceutical ingredient (API) development, the regulatory pathway, establishing the supply chain, and labeling. Developing a novel drug delivery device takes things to another level.

Many manufacturers shy away from the challenge, relying instead on proven technologies, so patients and clinicians don’t benefit from the most advanced user-centered design, and pharma companies can’t leverage the competitive advantage new technology delivers.

Here, I share some of the obstacles encountered conducting pilot builds in-house to help our clients bring devices to market – and give four pointers for ideal pilot manufacturing for clinical trials.

Develop your manufacturing process and architecture in tandem

3D CAD makes it all too easy to lose touch with reality and forget that the model on the screen is only an idealized representation. Zoom in 4,000%, and everything lines up beautifully. There’s no gravity, and parts have infinite stiffness, no tolerance, and perfect alignment. But, when you get natural variation in the manufacturing process, results can be disastrous. Components may not even fit together.

Once a design is frozen, making changes is expensive. After it’s passed to a high-volume manufacturer, costs become exponentially higher. Understanding manufacturing processes – and how changes can impact a project’s timeline – is critical for successful delivery. You need to prepare for the supply-chain ‘whiplash effect’: a tiny change at the top of the chain can mean seismic shifts at the end of it. That knock-on is the reason your product development strategy should incorporate pilot manufacture. Pilot manufacture keeps this effect in check by minimizing the volumes involved.

It’s vital to consider the whole supply chain, not just the component manufacturer, but the process equipment partners, filling, packaging, sterilization, and logistics. Each step has requirements to be understood and communicated to relevant parties. By developing manufacturing and assembly processes in tandem with device design, we can be flexible to insights arriving from either direction.

Pick the right partners for success

One of my first jobs was for a major automotive company. In their heyday, they ran the foundries that made the ball bearings for their vehicles. Today, they wouldn’t dream of it. No company does everything anymore. Few organizations would claim to be experts in all areas of drug delivery. Even those that manufacture and fill their own devices rely on external partners to produce the plastic resin and packaging materials and often outsource activities such as sterilization.

Partnering with experts to contribute specific knowledge is a time-efficient way to overcome obstacles in the development pathway. It also unlocks access to cutting-edge equipment and facilities that are expensive to maintain. While developing a breath-actuated inhaler, we engaged an external test house to conduct bio-compatibility evaluations on the device. We may have the skills in-house to perform this testing but maintaining accreditation for an activity that isn’t core to our business doesn’t make financial sense.

Know the limits

When developing a device, it’s essential to explore sources of potential variation. The same goes for the manufacturing process. You can use various tools to do this, but we frequently return to the humble ‘process failure modes and effects analysis’ (pFMEA). The pFMEA is a structured way to consider all the process steps – and how they could go awry. Developing a robust pFMEA ensures the team focuses on the highest risk areas and starts thinking about implementing mitigations.

A key checkbox for each manufacturing process step is if the results can be verified or validated. The US Food & Drug Administration Code of Federal Regulations Title 21 defines verification as “confirmation by examination and provision of objective evidence that specified requirements have been fulfilled.” Many processes can be verified using in-process measurement systems. But several can’t, for example, the joining of two plastic parts by ultrasonic welding. You can’t determine the strength of this weld without destructive testing. The ultrasonic welding process needs to go through process validation to determine the limits within which the process should be operated.

When communicating with stakeholders, it’s crucial to know the volume limits and have a realistic plan for producing parts representative of the final production process. For example, how many parts can the mold tools make? There’s a trade-off between tool production speed, tool cost, and tool life. Low-cost soft aluminum tools might be ready in two weeks but only suitable for 2,000 shots, whereas a more expensive hardened steel version might take 16 weeks (without validation) but last for over 100,000 shots.

Validating injection mold tools can be a lengthy process. Exploring the process window needs planning and performing multiple molding and measurement runs and subsequent analysis. Companies only want to bear this cost once, so experienced development teams need to hold firm when encountering adverse test results. I know of an auto-injector that showed promise early on, albeit with an infrequent failure observed in testing during development, that was allowed to pass into design freeze. More thorough testing during design verification revealed results that triggered the regulatory application to be rejected. Cue months of tooling validation needing to be reassessed.

Combination products require the delivery devices to be filled or co-packaged with primary containers of the API. Clinical trials complicate this because they need devices filled with the API or safe and sterile placebo. The filling process can be complex, especially when the API is highly viscous or uses technologies such as microspheres to sustain the release of active components over time. You need to factor in time to explore the filling and develop the process settings. Thought needs to be given to the amount of API and placebo available and the lead times for new batches as this can limit the amount of filled and finished devices.

Whitepaper-Breaking-the-mould-CDP-pdf
WHITE PAPER

Digital tooling to reduce time to market

DOWNLOAD HERE

Not documented? You’re not done.

Understanding the controls needed to manage risk is essential for a manufacturer delivering high-quality, safe, and reliable products. ISO 14971 sets out a best practice framework for managing risk in the context of medical devices. We advise creating a quality control plan that summarizes the production risk mitigation controls identified through risk assessment in a clear, concise format. This control plan also blueprints the actions needed if a specific limit or check is breached.

Anyone who has experienced an audit by a notified body or regulatory agency will recognize their love of records. The mature management systems used by large manufacturers often aren’t available for the short-run low volumes involved at the scale-up stage. Building a bespoke database compliant with 21 CFR part 11 to handle records can be a lengthy activity, particularly when compared with the pace of setting up paper-based systems.

Managing paper records generated by the manufacturing process can be challenging, putting storage and recall burdens on a manufacturer. Companies scan these documents soon after completion to reduce this burden. But the destruction of originals is risky, and the recall and integrity of e-records must be checked before destruction.

Pilot manufacturing helps optimize the journey of a drug delivery device to clinical trial. It’s not without its own challenges, but synchronizing manufacturing process and device design development, partnering with experts, having a plan for producing components that’s representative of the final production process, and keeping a handle on records puts you in a position to maximize pilot manufacturing’s potential.

References