The healthcare and medical device industry is heavily regulated to ensure quality, sustainability and – most importantly – the safety of human life. Device development is, therefore, a long and complex undertaking, with strict compliance regulations, long-term tests, quality checks and certifications.

Meeting new requirements like weight and size reduction, easier processing, flexibility, biocompatibility, stricter sanitation or the need for single-use instruments would be impossible without the use of polymers. From orthopaedic, surgical instruments and diagnostic equipment to drug-delivery systems, implants and vision aids, polymers have been used in the medical industry for decades. It comes as no surprise that an estimated 50% of all materials used in medical device manufacturing consist of plastics.

However, when it comes to the right polymer choice for a specific medical or pharmaceutical application, things can get complicated. Despite strict international regulations, as well as demanding requirements for medical polymers, one extra difficulty concerns the fact that there is no universally accepted definition of ‘medical-grade’ polymers.

The challenges of the past

The medical industry has been affected heavily by the ‘PIP scandal’, where Poly Implant Prothèse (PIP) used industrial silicone instead of surgical-grade silicone for breast implants, leading to rupturing. To this day, it keeps the courts busy. February 2017 saw the European Court of Justice decide, in the case of TÜV Rheinland, that notified bodies have to protect medical device end users, but are not legally liable.

PIP is just one of the most recent medical device failures that took place over the past few decades, showing the extent of unresolved questions and uncertainties.

In the 1990s, many polymer suppliers decided to withdraw from the medical market following similar problems. To stop the US market from drying up, congress passed the Biomaterials Access Assurance Act of 1998, which stipulated that raw material suppliers were not to be held liable for any product failure as long as they ‘meet applicable contractual requirements or specifications’. Since then, medical device manufacturers have invested heavily in making sure their products comply with regulatory requirements and are safe for intended applications.

However, a national and/or international definition of a ‘medical-grade’ polymer or plastic is yet to be put into place.

Application restrictions

After several high-profile and costly litigations in the ’90s, companies that actively market polymers for medical applications have developed policies for restricted or permitted applications. “There are a wide variety of ‘rules’ from polymer producers concerning which applications are allowed. The restrictions may often not be related to the expected performance of the polymer in the target application, but rather reflect the corporate environment and legal department’s decisions. They can have much more to do with perceived risk exposure to litigation [further] down the line,” says Siobhan Bastiansen, market manager, medical plastics at VELOX.

Examples of guidelines include skin-only contact, having no direct interaction with fluids entering the blood stream, staying inside the body for a maximum of 24 hours or 29 days and not being permitted to be used in medical applications.

It is very challenging for medical device and original equipment manufacturers (OEMs) to keep track of all the different and complex policies and disclaimers. “As a specialist medicalpolymer distributor, VELOX see its role as [being] the critical bridge between our polymer principals, customers and the device manufacturers to make the right polymer choice process a safe, successful, sustainable and convenient one,” adds Bastiansen.

There are very few polymer choices for medical device manufacturers that design products that remain in the body more than 30 days, and where the customer wants the confidence and support of the raw material supplier, for instance.

“Our partner, Lubrizol LifeSciences, is one of the very few polymer suppliers that does not restrict the use of its thermoplastic polyurethane (TPU) to 30-day implants, but instead has a disclaimer [stating] that the choice of polymer is up to the device manufacturer,” explains Bastiansen.

“Medical device designers are free to select from a TPU portfolio, where the most suitable grades are to be tested and considered for each specific application,” she adds. “On the other hand, if we have a customer who has a very low volume of demands for a coloured material for a non-invasive device, we can offer a range of options [for] advising [on a] minimum order quantity (MOQ) of coloured resins direct from the producer, or assist in finding a long-term sustainable solution with our medical compounding partner, IPC.”

Merchant discount rate impact

While polymer producers have created their own set of characteristics to define what a medical grade is, device manufacturers have been theoretically free to choose any polymer, as long as they have followed existing regulations, while carrying the risks associated with product liability. Many device manufacturers have relied on compliance with applicable standards, such as US Pharmacopeia Class VI and ISO 10993, with regard to biocompatibility when choosing a material for an application.

The new EU Regulation on Medical Devices 2017/745 (MDR) came into force on 25 May 2017, starting a three-year transition period that will make the law mandatory from 26 May 2020 to place a stronger emphasis on risk management and safety. Compared with previous medical device guidelines that MDR will replace, including the Medical Devices Directive (93/42/EEC), the law comprises 100 additional articles and two more appendices, new classification rules, extra surveillance and safety reports. It also reinforces the position of notified bodies, “with regard to their right and duty to carry out unannounced on-site audits and to conduct physical or laboratory tests on devices to ensure continuous compliance by manufacturers after receipt of the original certification”.

“For many small and medium-sized medical device manufacturers, the new, more demanding law may sound the death knell, as it will make the market entry for their products extremely difficult and expensive,” Bastiansen comments.

Still, when it comes to an industrywide, standard definition for medicalgrade polymer, the new MDR, like the MDD before, remains silent. There is no compulsory use of medical polymers for medical applications, as long as conformity with existing regulations is given.

Moving towards a definition

However, the German market is moving forward. In December 2016, the Association of German Engineers (VDI) implemented a committee for defining a standard for medical-grade polymers. VDI stated, “The aim is to define the requirements for the polymers for use in medical devices, and thus to develop a standard that can be used as a guideline for raw material producers and manufacturers of medical devices. The directive covers development, logistics, procurement and purchasing equally.” The VDI was to have presented a first draft of the guideline at the VDI symposium, ‘Plastics in Medical Technology’, which took place on 10–11 April in Friedrichshafen, Germany.

“We are fully supportive of the VDI aim, and think that a standard definition would bring more reliability, stability and long-term commitment for all sides. This is what polymer manufacturers and medical device producers alike need,” states Bastiansen.

Change management and long-term commitment are key

In the meantime, specialised medical polymer producers have already taken the opportunity to create indispensable value for medical plastics processors and OEMs.

To understand this peculiarity, one has to recall that only up to 3% of the world’s polymer production ends up in medical and healthcare applications. “This is really a drop in the ocean,” says Bastiansen. For many polymer suppliers that serve diverse high-volume industries, like the automotive, food, packaging and construction sectors, it may make no economical sense to invest in a market with such small potential volumes. However, several of these ‘industrial-grade’ resins have made their way into products that are considered as medical devices and are subject to MDR or FDA conformity.

For medical device manufacturers, this poses several risks and challenges; once companies have carefully chosen and tested a material to comply with all the complex laws and guidelines for medical plastics, and to meet the requirements for specific applications, they need to rely on long-term supply and predictability. In the industrial-polymer sector, sudden stops to deliveries or changes in raw material production are common, but if these are not brought to the attention of the device manufacturer they can be fatal, as medical device producers may have to repeat a complicated and expensive gauntlet of tests, where qualification and certification processes can take years.

“Polymer suppliers that develop and provide specialised polymers for medical applications have discovered a significant gap in this complicated situation to add value for manufacturers,” highlights Bastiansen. “Suppliers like Repsol or Lubrizol LifeSciences, which we have cooperated with for many years, have put transparent mechanisms into place to ease the process of change control for OEMs, and to also secure a long-term supply.” This way, the parties benefit from a close cooperation with mutual insight and knowledge exchange, where they can protect their business and products from expensive failures.

It is therefore important for these manufacturers to understand the ‘landscape’ of polymer producers. “The typical dynamic in chemical plants producing hundreds of thousands of tonnes, as we have for our polyethylene (PE), polypropylene (PP) and ethylene-vinyl acetate (EVA) resins, is to strive for continuous improvement in efficiencies, quality, innovation and economics,” explains Cristina Martinez, pharma and advanced packaging product manager at Repsol’s healthcare division.

“By implication, things are always changing; new grades bring advantages and old grades become obsolete, which is great for our industrial customers, but can be a nightmare for medical customers. The challenge in setting up our Repsol Healthcare portfolio has not been of a technical nature, in [regard to] developing innovative new grades. The much bigger task has been to understand the needs of medical and pharmaceutical companies, and to put the necessary product stewardship in place across all the stakeholders within the organisation. This means production, purchasing, logistics, R&D as well as sales and marketing,” Martinez adds.

Bastiansen summarises, “So knowing your supplier, and being sure that they know you and your application is the ideal scenario. They can give the right support, advise you and be there for the long term, which is crucial for success across the lifetime of the product. This is even more true with regard to the regulations of the new MDR.”

VELOX is a leading pan-European distributor of raw material specialities and is a solution provider for the plastics, composites, additives, rubber, paints and coatings industries. Founded in 1993 by Bernard Goursaud and Max Schlenzig, VELOX is headquartered in Hamburg, Germany. The company has 21 offices throughout Europe and has more than 230 experienced employees to support its customers across the continent.