In this Q&A, Audrey Turley, director of lab operations – biosafety at Nelson Laboratories, spoke with Medical Design Briefs about the critical importance of monitoring and managing material changes in medical devices. Even seemingly minor shifts — such as switching suppliers or altering processing steps — can introduce unknown additives or variations that impact biocompatibility and, ultimately, patient safety. Turley discusses how manufacturers can effectively document and justify changes, maintain regulatory compliance, and strengthen supplier relationships to ensure ongoing device safety. She also shares insights into trends shaping post-pandemic supply-chain strategies and the growing emphasis on proactive risk assessment and communication across the product lifecycle.
MDB: When medical device materials or suppliers change, what are the most common risks that you see for biocompatibility and overall patient safety?
Audrey Turley: When we talk about material changes, I think the thing that is the biggest — I want to say black box more than I want to say risk — is that suppliers will call a material the same name across different suppliers. But each supplier has proprietary formulas of additives that they place in their product. If we talk about a polypropylene or another polymer, there are different additives. Often what I find is that companies will move from one supplier to another thinking that they are changing one for one. They think it’s not a big deal. They think they’re making their product more cost-effective, which is what we want to strive for. But it ends up being a bit of a deceit. What we worry about from a patient safety perspective are the unknown additives that we need to make sure are addressed in that different material, even if it’s called the same name.
MDB: So how do regulators like FDA and international bodies expect manufacturers to demonstrate safety when the materials or processes change? And where do you see companies struggle the most?
Turley: Where I see companies struggling the most is explaining the change. Often, they’ll say, “this was the change; it’s no big deal” and they’ll go to the agency. The agencies do not understand the change and it’s almost in an effort to make it simple. Change for medical device companies needs a table. We need you to go component by component material or processing step and say, “this is what we did before, and this is the change and that makes it much easier to focus on.” Maybe it is one or two changes. But that’s way easier to say. This is all the same. These are the only changes. Here’s the potential risk to the patient, and here’s how we’re going to assess it.
MDB: For device manufacturers, what strategies can help determine whether a full biocompatibility test suite is needed after a change, or if a more streamlined approach can be justified?
Turley: Is it one material or five materials? If your surface area is 100 cm squared, and you are changing your catheter material on 80 cm squared to that device, you pretty much have a new device. You have to make sure you do a lot of testing to evaluate that [change], especially even when you think it’s a one-for-one change. Customers come to us with a bit of a sticker shock when they realize, “oh, we do have to go through testing because we don’t know about this material.” A streamlined approach can be used, for example, if you already use that material in another device that you have legally on the market and you have some testing and safety information [on that device]. Another scenario is if the change is small. If it’s a change on the device that’s less than 10 percent of the surface area and if it’s low risk or short term, often we can use an alternate approach rather than completing the full suite. You want to start first with lining out those changes and then understand how much of the device is actually changing, and that guides you on patient risk.
MDB: What best practices do you recommend for documenting material changes and maintaining traceability across products lifecycle, especially when preparing for audits or regulatory submissions?
Turley: It really comes down to documentation at the manufacturer’s site. I worked with a client who wanted us to do a gap evaluation. They’ve had a product that’s been on the market for a long time. I was going through the product life site, and it came to a point where I said, “oh, it looks like a material was changed here.” Well, this was the material for the entire device, and they had changed it somewhere along the life cycle but had not gathered any data on that material. And so while they had some clinical information, the clinical data doesn’t always trace some of the long-term issues we want to see unless it’s an implant. Then that clinical information is helpful. But other types of devices that are used repeatedly, for example, don’t always get that life cycle evaluation. I come through all this data, and I said, “You don’t have anything to support this. You’re going to have to have documentation on your change control.” Another thing in that documentation is that if you have small changes — maybe over the course of five years of a device — there needs to be a trigger in that change control that says, “We should actually look at that. We have made five changes now. They’ve each been small. We’ve been done justifications. We need to know how much of the device we changed.”
MDB: How important is supplier communication in identifying and mitigating risks from material changes, and what steps can manufacturers take to strengthen that relationship?
Turley: This can become a tricky relationship in your supply chain. And when we talk about suppliers and I talk about change control, the biggest gap is that some suppliers will make a change that they don’t think is a change. So, they won’t communicate it up to their customers. We had a customer who had was purchasing glass beads for part of their manufacturing. They would run cytotoxicity on these glass beads for an incoming quality check. So, it was fine for a long time and then all of a sudden, they started failing cytotoxicity tests and had biocompatibility issues that became cumulative through manufacturing processes. It’s not often that you remove biocompatibility issues; it’s more often that you add them during your processing. They reached out to the supplier and found that the supplier [changed its process to make it] cleaner.
When we think of making a process cleaner, we think about contamination of micro bacteria, so we think, “oh, let’s wear latex gloves.” The issue is that latex is cytotoxic. It also is a sensitizer, so it causes issues in a biocompatibility perspective. Where they thought they were improving their line, that improvement helped one area but also created another issue — one of risk for the patients. I tell this story to say have good relationships and understand change controls with your suppliers and what they consider. Understand what their change control level is and think about that in correlation to your device and the risk to the patient. So if you have an implant device, of course, those contracts are much stricter. But even with an intermittent-use device, we have to be mindful of exposure to things like latex, because that can be quite harmful to some patients if it’s not labeled appropriately.
MDB: What trends or innovations do you see shaping the way companies address material changes and safety?
Turley: We learned a lot with COVID. It shaped a lot of different industries. But for medical device, supply-chain issues became really critical. And one trend that has come out of that is that companies want to have more than one supplier, and they also want to have something more local. As we deal with shifting changes in our political environment, too, these are things companies are evaluating so that they can stay in business and keep their devices on the market and get them to the patients that need them. Try to recognize whether this is a different material.
Conclusion
Material and supplier changes are inevitable in today’s dynamic medical device landscape, but the risks they pose can be minimized through vigilance, transparency, and thorough documentation. Manufacturers who take a systematic, data-driven approach to change control and maintain open communication with suppliers and regulators will be best positioned to ensure both compliance and patient safety.
In an era of evolving materials, global supply chains, and increasing regulatory scrutiny, staying proactive about biocompatibility and traceability isn’t just good practice, it’s essential for maintaining trust and delivering safe, effective medical devices to patients worldwide.
This interview was conducted by Sherrie Trigg, Editor and Director of Content, Medical Design Briefs. For more information on Nelson Labs, visit here .
