Aug 28, 2007

Biocompatibility testing of medical devices

I spent today writing the biocompatibility testing protocol which is required for product validation, engineers writing testing protocols is what happens when you don't have dedicated regulatory or QA. I'm sure that is making some of you cringe- but I promise I write a better procedure than blog post.

For the testing, which should be done on the final device after final processing, you basically just round up ISO 10993 and look at the biocompatibility testing chart and then call around for some GLP quotes. The big three places to get biocompatibility testing done seem to be NAMSA, Apptec, and Nelson Labs. There are also regional players, in our neck of the woods its Pacific Biolabs (who have decent information on their webpage here). Most people who have been around for a while have their more liked lab that they use most often. I wouldn't call it a favored lab because the relationship is hot and cold depending on how long the lab is taking- a bit silly since most testing requires standard amounts of extraction, incubation or other times. I annoy them all depending on the whims of my betters, I probably request five quotes for every one test we actually perform, sorry if you're the one doing the quoting, but thats how it works here.

For the most part, our required tests are fairly straight forward, we do have an "Additional test which the FDA may consider applicable" note under one test. In cases like that, you can generally do the test, or spend just as much time and money justifying why you don't have to and then have the FDA tell you they'd really like to see the test done and why don't you just go ahead and do it. We're just going to go ahead and get the additional test done.

I spent a bit of time trying to convince people that Murine Local Lymph Node Assay (LLNA) was the way to go for sensitization testing. Its a newer test, that is quicker and supposedly more accurate, it costs the same, and is also supposedly better from an testing animal welfare standpoint. I made some progress, but we could revert back to the Guinea Pig Maximization test at any time someone gets antsy. We just last year switched to LAL tests from rabbit pyrogen tests.

There really isn't any trouble anticipated, we're using standard tubing, components and assembly methods for the disposable component. These materials have probably been tested thousands of times previously, which is a little depressing, but its less than $20K for the testing for our device which takes about two months, so its not a huge burden for a very nice little piece of mind. The rationale behind the repeated testing is no two processes are exactly the same so better to be safe than sorry. Once the samples get back from sterilization we're good to go and hopefully the remainder of the work required for biocompatibility validation is just sorting out test results into binders.

UPDATE: I just wanted to make clear that not all devices can get away with a relatively easy biocompatibility testing as we can. The longer the device is in contact with the patient, the more rigorous the testing and some of the tests (genotoxocity or implantation for example) can be $20K+ each and some can take 4+ months. I also clarified that the testing should be done on the final device after final processing as per the comments.

12 comments:

Anonymous said...

Great blog, great post. I'm not new to regulatory, but I am new to devices. Are you required to do biocompatibility testing for each device? Each material used in the device? What's the story!

Jon said...

It depends. If each material has been proven to be biocompatible, then maybe all in combination are also biocompatible. However, biocompatibility should be demonstrated on the final materials after final processing. It's sometimes a gray area. The sources cited in the blog post should be willing and able to help. I have a good relationship with NAMSA and am happy to share a contact if interested.

Anonymous said...

Thanks for answering. I'm just trying to learn as much as I can about device regulation, and your blog is a big help.

Anonymous said...

whats your email?

JCK said...

You can find Jon's contact information at his blog:

http://www.creoquality.com/

Good luck!

Patrick said...

We have a radioactive device, and the act of charging with radiation has an impact on the surface chemistry, so we need to conduct biocompat tests. Now, our device has a very rapid decay rate, and with a month or so it is effectively not radioactive any more...but testing house are not willing to test it because of the stigma of having once been radioactive. Any idea how these types of devices should be tested?

Anonymous said...

I am working on wound care products. There is a change in material on one of the components of this dressing. Now, this material as a paper, remains on the product and thrown away when customer uses it so it does not come in contact with skin.
The manufacturer of this material is changed so we want to test bicompatibility. I don't know if I really need to do all three cytotoxicity, irritation and sensitization tests?
Is cytotoxicity test enough?

Anonymous said...

to 11/12/08:

If the material is chemically similar to previously cleared materials, then you may wave it per ISO. I do this as part of my job (toxicological reviews of raw materials used in medical devices both Chem and Bio) This saves time, money and needless animal testing. Like all contract labs you need to manage them not they manage you. Remember they are trying to sell their services which you may not need to do depending on use and duration. Some the new tests proposed are not embraced by the approving regulators.

Anonymous said...

Hi,I got to know that in Asia Region, BioComp test is availalble at TUV SUD PSB in Singapore.

http://www.tuv-sud-psb.com.my/biocompatibility.aspx

PSB provides a comprehensive range of services such as compliant biological, chemical and physical testing in the evaluation of the biocompatibility and safety of medical devices and biomedical materials. These preclinical studies are carried out under conditions and quality management system in compliance with GLP (Good Laboratory Practices).

Delores Lyon said...

I have been trying to look into different types of medical testing for a paper I'm writing. It looks like bio compatibility really is important when testing devices! It would be a shame if a device failed to work after being used to help save a life. https://www.nelsonlabs.com/

Biocompatibility testing for medical devices said...

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