"design" of a pharmaceutical product purity analys

[ricopalazo]

Hi all!
I'm looking for some informations about the concentration of sample require generally for the purity analysis of a pharmaceutical product.
Someone told me 1mg/ml API is require.
I know that depend of the solubility and so... But is there a minimal value for the autorities?
I can't find any informations about it in the guidelines or pharmacopeas (USP, Eur.).
Can someone give me a link or an indication of what is best to do to be compliant?

Thanks in advance

[shaun78]

As far as I am aware there is no minimum specified amount by the USP/EP/JP for impurity testing of an API.

In the past we have generally picked an amount that allows us to accurately detect the impurities that we know should be there (starting materials, intermediates, etc).