Extractables testing replicates - Chemical Characterization ISO 10993-18

[Manel Mou]

Dear all,
I have a question related to chemical characterization according to ISO 10993-18(specifically extractable testing) , the standard is recommending to perform extraction and analytical testing in triplicates and stating in the other hand that a smaller number of replicates may be more practical.
what do you think about that? will be 1 replicate or 2 replicates sufficients to generate acceptable data (because performing more replicate is spending more money)
anyone of you knows about NB expectations related to this topic?

THANKS in advance.

 

[planB]

In my experience, notified bodies are just starting to dive into such specific analytical topics as testing replicates. So currently, you might at most be asked for a rationale for not performing analytical testing in replicates. In fact, this is still an area of discussion and development without a final conclusion on the level of ISO standards development working groups; and for this reason, the wording in current ISO 10993-18 is rather "soft".

In case analytical testing variations would not significantly affect your overall test result, you might be in a position to built a rationale for not testing in replicates. You could achieve this by introducing worst-cases (e.g. extraction conditions that exceed the actual clinical conditions, adequate uncertainty factors in your AET (analytical evaluation threshold) calculation) or by measuring substances in quantities with a large MOS (margin of safety).

This is for the time being; with the rapid progress in (accredited) analytical methods as well as increasing regulatory focus on leachables / extractables testing, this may change over the next couple of years.

HTH,

 

[Manel Mou]

In my experience, notified bodies are just starting to dive into such specific analytical topics as testing replicates. So currently, you might at most be asked for a rationale for not performing analytical testing in replicates. In fact, this is still an area of discussion and development without a final conclusion on the level of ISO standards development working groups; and for this reason, the wording in current ISO 10993-18 is rather "soft".

In case analytical testing variations would not significantly affect your overall test result, you might be in a position to built a rationale for not testing in replicates. You could achieve this by introducing worst-cases (e.g. extraction conditions that exceed the actual clinical conditions, adequate uncertainty factors in your AET (analytical evaluation threshold) calculation) or by measuring substances in quantities with a large MOS (margin of safety).

This is for the time being; with the rapid progress in (accredited) analytical methods as well as increasing regulatory focus on leachables / extractables testing, this may change over the next couple of years.

HTH,

thank you for your helpful answer