Total % impurities profile; repeatbability from duplicate

[Rob Burgess]

When assessing impurity results by % area/area of the main peak, for duplicate preps from drug product samples what would you say constitutes “repeatableâ€

[tom jupille]

I’d probably plump for about 0.5 - 1% for total? Is this about right? Is there any guidance on this anywhere?

In general, "suggested" repeatability for major peaks in FDA/USP/ICH is about 1%, so by implication, that sounds about right, but I'm not aware of a specific guidance for that situation.