Related substance concentration
Posted: Mon Dec 13, 2010 5:37 pm
I mean that how to set the concentration ie ppm required in the analysis of related substances in HPLC method development.
Hi
As you adress the question as related substances I have to assume you mean the pharmaceutical buisness, so generally:
As such the starting point is the ICH guidelines, Q3A-B handles the minimum requirements for reporting limits for drug substances and drug products. Togehter with guideline Q2(R1) they form a base.
Practically one tend to drop below the limits mentioned in those guidelines.
For new products/substances especially more toxic impurities or PGIs (potential genotoxic impurities) separate guidelines (FDA and EMA) are to taken into account. If significant changes are made to older products these guidelines might apply as well for older products.