Setting Nitrosamine Impurity limits

How we can set limits for Nitrosamine impurities.whos limits are not provided in any Nitrosamine Impurity guidance

Very interesting question.
@Naiffer_Host who can give advice on this, our friends from @Lhasa?

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Hi Vijay, the answer to your question is that apply Read Across strategy and identify most structurally as well as in terms of potency similar to already identified NA impurities in guidance and use that limit for control strategy.
To achieve above appropriate in silico tools such as DEREK, MULTICASE etc are applied.
Thanks and Regards.

@Vijay123 Thanks for the post. At a recent USP’s Nitrosamine Workshop, community member Dr. Raphael Nudelman @conudel deliver a great presentation highlighting how limits are established for non-traditional Nitrosamines. You have access to the recording via the post below. Also feel free to connect or tag community members.

@MichaelBurns @fernandaw any chance we can have a webinar series with Lhasa to explore How-to of in-silio tools?


This should be something we could help with. I’ll be in touch

But if limit is calculated as per guideline and how to decide LOQ level if limits 7.5 ppm is it used 0.03ppm LOQ or as usual practice follow as per LOQ LOD prediction.