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  • 1.  Biocompatibility -representative sample

    This message was posted by a user wishing to remain anonymous
    Posted 12-Dec-2018 09:11
    This message was posted by a user wishing to remain anonymous

    ​Need your help urgently ...
    We had this query from the third party reviewer for our reusable device on biocompatibility :
     Please explain for each test exactly what test articles were used (whole device, components, which components, etc.) and how/why they are representative of the final, packaged device

    How would I need to address the 2nd part ?

    Thanks,


  • 2.  RE: Biocompatibility -representative sample

    Posted 13-Dec-2018 04:01
    Hi Anon,

    ISO 10993-1:2018 clearly states that : "Testing shall be performed on the final medical device, or representative samples from the final device or materials processed in the same manner as the final medical device (including sterilization, if needed)"

    That means that during testing if the device is comprised from various parts and it cannot be tested as a whole, you have to indicate the parts that have been tested and how they represent the medical device. In most of the cases you have to state and justify the portions you choose from each part.

    Hope that helps

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    Spyros Drivelos
    Medical Devices Manager
    Agia Paraskevi, Athens
    Greece
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    Original Message


  • 3.  RE: Biocompatibility -representative sample

    Posted 13-Dec-2018 04:56
    Also consider looking at ISO 10993-12 which describes how samples may be prepared.  To be honest, this is not an uncommon question being asked and unfortunate that some biocomp labs do not clearly describe the unit under test, how it was prepared, and what was actually tested.  As an example, some devices can not be physically tested so a solution has to be created from extracts of the device in order to be tested.  You can not cut off a piece of an implant to stick on test subject skin for sensitisation.  The question is valid as you need to describe what parts, components, or materials of the actual device were tested and why this is representative of the final packaged device.  Such that is you test only part of a device or certain components, why would this be representative of the entire device.

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    Richard Vincins RAC
    Vice President Global Regulatory Affairs
    Pembroke Pines FL
    United States
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    Original Message


  • 4.  RE: Biocompatibility -representative sample

    Posted 13-Dec-2018 08:28
    On other thing to address in your response is the packaging. You should have some sort of accountability of what you removed from inventory for testing that relates back to all of the lot information. That lot information should be objective evidence that the device went through all manufacturing and processing steps, including packaging and sterilization. If that is true, then in your response, simply state that the device was in its final, finished packaging when sent for testing.

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    Lisa Olson
    Minneapolis MN
    United States
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    Original Message


  • 5.  RE: Biocompatibility -representative sample

    Posted 14-Dec-2018 10:46
    ​Hi Anon,

    You've had good input so far; I would only add a few somewhat related points:

    * If the device was divided in any way to form the sample, be sure to address whether the proportions of materials were maintained.  if they were not, some regulators will raise concern about possible dilution of extracted substances (i.e., some device materials under-represented in terms of surface/volume ratio of extraction vehicles in the testing).

    * If you have multiple components (e.g., an implant and delivery system), you should confirm the delivery system was not included in the testing of longer term endpoints that apply only to the implant.  Same potential concern here, possible dilution effects.

    * Finally, if there are non-contact portions of the device (e.g., a handle), you should confirm they were excluded from the test samples; if they were included, you should confirm the surface/volume ratio of extraction vehicles was based only on the contact portions of the device.

    Hope this is helpful!

    Ted

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    Theodore Heise PhD, RAC
    VP Regulatory & Clinical Services
    West Lafayette IN
    United States
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    Original Message


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