Reporting Threshold in Impurity tab

Empower2018

ICH defines the reporting threshold as any value ABOVE WHICH should be reported. So lest say my impurity response is Area against Main Component Area in % (Area of known or unknown impurity/Area of Main Component*100) and my method states to "report any impurities greater than or equal to 0.1%), what value do I then put into the reporting threshold in the Impurity tab of my processing method to include 0.1% and higher? If I put in 0.05 then surely Empower excludes 0.05 and only includes 0.06 onwards when it should be including 0.05 (which rounds to 0.1% and should be included)? Or does Empower see any value greater than 0.05 as 0.0500001 or 0.05098766 etc. I cant figure out how to account for this when deciding what to put into the reporting threshold column. Any ideas?

MJS

I propose you test it out.  Take any injection you like from a sample set and simply change the value in the processing method accordingly, see what changes in the review window.  I can't imagine you'd have to formally process in order for it to work/preview the impact of changing the threshold value.

So, if the injection you pick has a peak at 0.1564%, for example.  Set the threshold to 0.1 and it clearly should be included.  Change the threshold value to 0.2, see what happens since this example would round to 0.2.  Change it to 0.160, 0.15, 0.156, anything you'd want and that should confirm for you how much precision Empower uses in the calculation/determination.

Empower2018

Thanks ill test these precisions when I get a chance next. 

shaunwat

I would advise writing your own code to handle this. I've never been happy with how Empower handles itself with respect to the impurity processing tab since it was added in FR2.