ISO 10993-1:2018 Clause 4.11 - New testing of historical devices?

[Stephan]

Hello to all,

we are legal manufacturer of medical body electrodes (ECG, Neutral Electrodes, Defibrillation Electrodes). We are preparing a biological evaluation according ISO 10993-1:2018 for our ECG Electrodes. The ECG electrodes are classified as follows: class I in EU according REG (EU) 2017/745 (MDR), class II in USA according 21CFR870.2360. The ECG electrodes have been marketed since many years.

They were approved with former ISO 10993-1:2009.
In the case of the ECG electrodes, the nature of body contact is indicated with Surface device intended to be used on intact, uninjured skin and the
contact duration is indicated with "limited (<24h)" and prolonged (24 h up to 30 d).
Consequently, the ISO 10993-1:2009 standard requires the assessment of
- Cytotoxicity
- Irritation or intracutaneous reactivity
- Sensitization


Now, our consultant who is helping us with the biological evaluation claims, that we have to perform chemical characterization for materials according ISO 10993-18. We recognized, that it is demanded in ISO 10993-1:2018. But we argue with clause 4.11 from ISO 10993-1:2018, which indicates:
[...]
4.11 This document shall not be used to mandate re-testing of historical products assessed previously using the appropriate edition of this document at the time of the assessment. Nevertheless, compliance to this new edition shall be shown, by providing a justification for omission of further testing. Where recommendations for endpoint assessment per Annex A are different from prior published versions of this document, a history of safe clinical use can be used to document why additional testing on a commercially-marketed medical device is not needed. However, if any of the changes described in Clause 4.9 occur, an evaluation of the biologic risks related to the change shall be performed using the current version of this standard.
[...]

We think, that we do not have to perform new tests (chemical characterization), as we only have historical devices, marketed for a long time. We just have to write this in the biological evaluation and reference to the clinical evaluation report, as well.
But our consultant does not accept this argumentation and insists on chemical characterization testing. By the way, the consultant does not benefit from new testings.

I would appreciate your opinions. What do you think about omitting chemical characterization by using clause 4.11 from ISO 10993-1:2018.

Thank you for your help.

 

[planB]

Stephan,

your consultant is somewhat right - quote from ISO 10993-1:2018, section 6.1:

Gathering physical and chemical information on the medical device or component is a crucial first step in the biological evaluation and its associated process of material characterization.

So evaluating the endpoint "material characterization" is a mandatory first step in order to full this requirement from section 4.11: "compliance to this new edition shall be shown, by providing a justification for omission of further testing." If you have already enough material-characterization data, you do not have to (re-) do extractables and leachables studies ("chemical characterization"). Section 5.2.2 (a) and the NOTE therein about common consumer materials and FDA draft guidance about some intact-skin contacting materials might provide you with additional rationales for not performing chemical characterization tests.

However, especially with notified bodies, this might be an uphill battle: the energy and effort you may have to invest into getting your "no-test" approach accepted might exceed the time and cost you may spend on a small up2date chemical characterisation study, plus a confirmatory cytotoxicity test as a sensitive first biological end point. In case you do not identify any extractable/leachble substances of concern, you will definitely be a position for omitting irritation and sensitization testing.

HTH,

 

[Stephan]

Thank you very much for your reply. I agree, presenting a passed test is always easier, rather than explaining a root of argumentation. In our case we will have to do about 10 to 15 chemical characterizations and obviously we are not concerned about the safety of our products, but we are a little afraid about the insecure outcome of these characterizations and following toxicological evaluations. This procedure will create costs and binds resources and that is why we want to avoid unnecessary tests.

section 6.1 states as well - quote from ISO 10993-1:2018, section 6.1:

If the combination of all materials, chemicals and processes has an established history of safe use in the intended application, and the physical properties have not changed, then it is possible that further characterization and additional data sets (e.g. chemical analysis of extracts or biological testing) will not be necessary. In this case the rationale shall be documented.

Together with section 4.11 it seems that it is not the intention of ISO 10993-1:2018 to create more testing - ISO 10993-1:2018, section 4.11:

4.11 This document shall not be used to mandate re-testing of historical products assessed previously using the appropriate edition of this document at the time of the assessment.

Nevertheless, we have to discuss the pros and cons internally and decide which way we want to go...

Thank you again for your input, helps a lot. This is really an important platform, appreciate it.

Best regards

stephan