Chromatography Forum

4.2. Impurities (Quantitation)
Accuracy should be assessed on samples (drug substance/drug product) spiked with
known amounts of impurities. (this is as per ICH Q3R1)

I just want to know how is this being made?

Am I right if what I'm going to do is to place a placebo and spiked it with API and Known impurity. Then calculating the percent recovery of each. Thanks.

I see that the API may already contain some of this unknown impurity. So if you spike with API and then spike with that known impurity, you need to do amount by standard addition type calculations, subtracting out the amount in the API to get recovery of unknown substance spike.