When validating an HPLC impurity method, is there an industry standard for acceptance criteria of agreement between two analysts?
We typically use NMT +/- 10%, but this is based on a peak with good response. I am currently working with a method that I’m not at liberty to change at this point and my impurity has a very low peak area (~800-1000).
My concern is that any difference will be greatly magnified at this level. Is it reasonable/acceptable to widen my acceptance criteria to 20% or even 25% agreement between two analysts?
I thank you in advance for a quick response. Deadlines are looming…