Has Anything Changed Since Your Last Biological Evaluation? Questions Every Manufacturer Should Ask

    Most biological evaluations are written for a specific device at a specific moment. The device then keeps evolving: a supplier changes a resin grade, a site switches cleaning agents, a new size joins the range, or the sterilization cycle is adjusted to improve throughput. Each decision may be reasonable on its own; taken together, they can leave the evaluation describing a device that no longer exists in quite that form.

    In This Blog Post

    • Why device changes and revised standards can quietly outdate a biological evaluation
    • What ISO 10993-1:2025, the EU MDR and FDA guidance expect from manufacturers
    • Nine questions to test whether your existing evaluation still holds
    • How chemical characterization and existing data can reduce the need for new testing
    • What to do next: confirm validity or run a structured gap analysis

    The Standards Have Moved Too

    The framework around it has also moved. ISO 10993-1 was published in a sixth edition in November 2025, reorganized to align with the risk management process of ISO 14971, and a revised ISO 10993-3, covering genotoxicity, carcinogenicity and reproductive and developmental toxicity, followed in 2026. In the EU, the MDR asks manufacturers to pay particular attention to the choice of materials and substances, especially as regards toxicity, and to their compatibility with biological tissues (Annex I, Section 10.1). In the US, the FDA guidance on ISO 10993-1 describes risk-based approaches to decide whether biocompatibility testing is needed at all.

    None of this means every evaluation has to be rewritten. The 2025 edition states that it does not mandate re-testing of devices already on the market with established and acceptable safety profiles. What it does call for is a clear, documented view of whether the existing evaluation still holds, and the questions below are a practical way to get there.

    Nine Questions to Ask About Your Biological Evaluation

    1. Has the Device Changed Since the Evaluation Was Written?

    Start with the obvious and work outward: materials and formulations, colorants and additives, adhesives and coatings, suppliers, manufacturing sites, processing aids, cleaning and sterilization. Your change control procedure should already capture these, and it should ask explicitly whether each change affects the biological evaluation. As a useful reminder of how broad the notion of "material" can be, the EU guidance MDCG 2020-3 (written for legacy devices under the MDR transitional provisions) defines it as any substance used to make or compose the device. Even small changes in composition can matter.

    2. Is the Intended Use Still the Same?

    New indications, longer contact durations, different patient populations or a new type of body contact can change the biological risk profile, even when the device looks exactly the same.

    3. Does Your Evaluation Explain Its Decisions, or Only List Test Results?

    Reviewers expect to see the reasoning behind each biological endpoint: why it applies, how it was addressed and, where no test was performed, why that was justified. A file built mainly as a collection of laboratory reports is harder to defend when questions arrive.

    4. Were Tests Added "Just in Case"?

    After a standard is revised, adding tests can feel like the safest option. Sometimes it is; often, the same question could be answered with existing data, chemical characterization and a toxicological risk assessment, at a lower cost and with fewer animal studies.

    5. How Solid Is Your Chemical Characterization?

    Check whether the analytical approach is still appropriate for the device and its contact category, whether detection limits are adequate for the exposure being assessed, and whether the substances detected have actually been evaluated toxicologically rather than simply reported.

    6. Are You Making Full Use of the Data You Already Have?

    Clinical history, published literature, earlier test results and information on materials with a long record of safe use can all support the evaluation, provided their relevance to the current device is justified.

    7. Is the Evaluation Connected to Your Risk Management File?

    The 2025 edition places biological evaluation firmly inside the ISO 14971 process. When the two documents are maintained separately, on different schedules and by different people, inconsistencies tend to appear; reviewers usually find them.

    8. Would the Evaluation Hold Up in Every Market Where You Sell?

    EU and US expectations overlap a great deal, though not completely. An evaluation prepared with one authority in mind may need additional justification for the other, particularly around test selection, the use of chemical data and, in the US, the edition of the standard you declare conformity to.

    9. What Triggers a Review of the Evaluation?

    If the answer is "an audit" or "a deficiency letter," the process is reactive. A defined link between change control, post-market data and the biological evaluation means the file is updated when the device changes, not when someone asks.

    What to Do With the Answers

    If most answers are reassuring, record that conclusion: a short, reasoned statement confirming that the evaluation remains valid is useful evidence in its own right. If several answers raise doubts, the next step is a structured gap analysis, looking at where the evaluation falls short and at the most efficient way to close each gap. In many cases, that work relies more on chemistry and toxicology than on new biological testing, which is good news for budgets, timelines and animal welfare alike.

    Keep Your Biological Evaluation Defensible

    QbD Group's regulatory toxicology experts help medical device manufacturers review existing biological evaluations against ISO 10993-1:2025, run structured gap analyses and build chemistry- and toxicology-led strategies that limit new testing.

    Not sure whether your evaluation still holds? Get in touch with our experts to find out where you stand.

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