Biocompatibility requirements for a Class IIa medical device

[dvear]

I wonder if anybody can help me or point me in the right direction please? We are introducing a class IIa medical device; similar devices are already very common. We have almost completed our auditing for the CE marking, however our auditor has asked us to confirm the fabric dyes are safe to use. The product is a mattress so should not really have direct skin contact but it is possible for it to have direct contact. We are not the actual manufacturer but in terms of the MEDDEV we are.

The product has been tested to 10993-5 and 10993-10 but not in every colour. Our auditor is comfortable that this is not a major issue and we have MSDS sheet and CAS number for the dyes and we have researched them on the European Chemical Agency's website and there have been no issues raised on there.

Our auditor has asked that we obtain a statement from a biocompatibility expert confirming the above. Despite sending lots of queries to testing houses I have not found anybody who will offer such a service.

Can any of you help?

Thank you.

 

[Michael Malis]

...We have almost completed our auditing for the CE marking, however our auditor has asked us to confirm the fabric dyes are safe to use...

The product has been tested to 10993-5 and 10993-10 but not in every colour. Our auditor is comfortable that this is not a major issue and we have MSDS sheet and CAS number for the dyes and we have researched them on the European Chemical Agency's website and there have been no issues raised on there.

Our auditor has asked that we obtain a statement from a biocompatibility expert confirming the above. Despite sending lots of queries to testing houses I have not found anybody who will offer such a service.

More information is needed. Such as, what is the percent of the colorant in your product?
Because there are a number of colorants available (and not all colors were tested), without testing results it is impossible to confirm biocompatibility!

 

[Ronen E]

Hello dvear and welcome to posting on the Cove

I recommend you contact NAMSA (I have no affiliation with them, only good experience), and ask them to give you a quote on their expert toxicologist formal opinion. Once you engage, you'll be able to share with the expert all the relevant information, and they will either advise that more actual testing is required (including the reasoning) or issue the formal written opinion that you seek, based on the information already available.

Good luck,
Ronen.

 

[milagre]

Hi Dvear,

Ronen's advice is good. From my own limited experience, I would expect that if the dye is not documented as biocompatible, but literature suggests it should be, that you will only need to perform cytotoxicity testing (in vitro) on each color. Compared to sensitization/irritation testing, the cytotoxicity should be pretty low-cost. Overall, I think it is fairly foreseeable misuse that the patient would directly touch a mattress, even if that isn't how the mattress is designed to be used (therefore biocompatibility should be required).

Hi Ronen,

I have a semi-related question to the OP based on your answer. Is it normal for manufacturers to compose the written opinion on why further testing is not needed based on literature review (assuming the reviewer is qualified)? Or is it more common (even required?) that a third party issues the opinion?

I always assumed as long as your internal reviewer is qualified to issue the opinion, it would be no problem.

 

[dvear]

Thanks Ronen

I had contacted them already and am waiting for their response, I'll wait to see what they come back with.

 

[Ronen E]

Is it normal for manufacturers to compose the written opinion on why further testing is not needed based on literature review (assuming the reviewer is qualified)? Or is it more common (even required?) that a third party issues the opinion?

I always assumed as long as your internal reviewer is qualified to issue the opinion, it would be no problem.

I assume that if you have an internal reviewer who is equally qualified (e.g. an experienced toxicologist), and the reasoning is sound, that should be enough. However, I've never gone down that path.

Cheers,
Ronen.

 

[MIREGMGR]

(...) if the dye is not documented as biocompatible, but literature suggests it should be, that you will only need to perform cytotoxicity testing (in vitro) on each color. Compared to sensitization/irritation testing, the cytotoxicity should be pretty low-cost.

I don't think this approach is supported by the actual wording of the standard series.

Is it normal for manufacturers to compose the written opinion on why further testing is not needed based on literature review (assuming the reviewer is qualified)? Or is it more common (even required?) that a third party issues the opinion?

I always assumed as long as your internal reviewer is qualified to issue the opinion, it would be no problem.

My interpretation of the wording of the standard is that, if the "established history of safe use" alternate compliance-course is to be followed, no additional validity accrues to the analysis based on the expertise of the person that conducts that analysis. It's only the reviewed historical documentation that matters.

The value of impressive credentials on the part of the historical reviewer might be in convincing a regulatory overseer that the reviewer does fully understand the historical documentation and therefore the analysis process itself need not be investigated.

I don't think there's support in the standard series though for an expert to simply state "yeah, that material is safe in your application", except via the historically-documented-prior-applications route.

 

[milagre]

I don't think this approach is supported by the actual wording of the standard series.

I think you are right. The wording of the standard says you should do: risk management --> testing (unless risk evaluation determined risks are acceptable and no further testing is needed) --> biological evaluation report --> conclusion.

The method I talked about was based on a whitepaper from Parker Hannifin (Whitepaper: Biocompataibility ofAnesthesia/Respiratory Products). So the method is not from the standard, and it may be the case that it is only recommended in the whitepaper due to the risks associated with respiratory devices. I think it is a good approach though. There is no animal testing in the cytotoxicity test, so the only reason not to conduct the test would be time/money.