Eurofins Medical Device Testing offers biocompatibility expertise and experienced testing to ensure rapid turnaround times with the highest level of service, and most advanced technologies. MDB spoke to Eurofins’ director of biocompatibility, Geoffrey Moodie, PhD, who answers some commonly asked biocompatibility questions.

Geoffrey Moodie, Eurofins

MDB: Do device manufacturers always need Biological Risk Evaluation documentation?

Geoffrey Moodie: Yes. These documents should be thought of as the collected evidence that the biological risks have been appropriately evaluated for your device. The Biological Evaluation Plan and Report are described in ISO 10993-1.

MDB: Must a Biological Evaluation Plan/Report be written by an accredited laboratory, or can a company's quality department write these documents?

Moodie: The ISO 10993-1 introduction calls for experts with appropriate experience and/or training to evaluate a device. While it does not call for a particular accreditation, you may need to show that the person(s) involved have the necessary expertise.

MDB: What if a device manufacturer already has biological safety information for a device?

Moodie: The Biological Evaluation Plan should take into account all of this information. It may be that, upon the evaluation performed as part of the plan, there is already sufficient information to address biological risk and no further testing is needed. However, it will be important to have this document to demonstrate that biological risks were appropriately evaluated.

MDB: Is a Toxicological Risk Assessment always needed after E&L testing?

Moodie: A Toxicological Risk Assessment should be planned following E&L Testing. While there may be some instances where it is not needed (for example, if no compounds are extracted), these tend to be very infrequent exceptions. Even if you consider your raw material to be “clean,” there are often processing residues introduced into and onto your final product.

MDB: How do you handle a substance with limited or no toxicological data?

Moodie: Our toxicologists use a variety of techniques to evaluate the potential toxicity of such compounds by looking at better characterized compounds with similarities in structure, using computational techniques, and consideration of appropriate safety factors.

MDB: Can any of a device’s in vivo studies be conducted non-GLP?

Moodie: GLP is the expectation for in vitro and in vivo data used to support the safety of a device. Use of non-GLP data for this purpose will likely require a careful justification as to why GLP was not an option. However, not all studies need to be GLP. For example, basic exploratory studies carried out to determine whether a new concept has any potential utility may not require GLP?

MDB: How do we handle testing of a device that is made up of patient and nonpatient contacting portions?

Moodie: When performing extractions for biocompatibility, testing it can be important to ensure that you isolate any components that will not have patient exposure as these may lead to false positives. This may be done by removing the noncontacting materials or “masking” noncontacting components so that the extraction fluid cannot reach them. Note that the device tested should otherwise be as close as possible to the final finished product, and any differences between the test sample and final finished product documented and justified.

MDB: What if a lab says they need to cut a device that is too large to test. Should there be concern?

Moodie: You should pay attention to whether or not cutting will result in materials being exposed that would otherwise not come into direct or indirect contact with the patient/user. Discuss this with the lab to ensure the device is sectioned in a way that the results will reflect the materials to which the patient/user are actually exposed.

MDB: Why should a Biological Evaluation Report be considered a living document?

Moodie: Changes in materials, manufacturing processes, packaging, sterilization, shelf-life, storage/transport, intended use, or reports of adverse events are all reasonable to expect within the device lifecycle. These changes will need to be evaluated for their impact on biocompatibility and the Biological Evaluation Report updated accordingly.