Chromatography Forum

Does any one know how create a custom field to calculate content uniformity( Acceptance value) .
Please give me details about the formula and the parameters of the CF .
THANKS

I would imagine its very easy to calculate what you are looking for but we need more information, how is content uniformity calculated in your lab, whats the formula? And whats the acceptance criteria in your specification eg content uniformity needs to be between 98-102%.

Does any one know how create a custom field to calculate content uniformity( Acceptance value) .
Please give me details about the formula and the parameters of the CF .
THANKS

Do You mean assay till 98.5, 98.5 to 101.5 and up to 101.5 per cent?
for K 2.4 (10 tablets) and K 2.0 30 tablets?

YES i mean
M=X̅ if  98.5%≤ X̅≥101.5%
M= 98.5% if X̅<98.5%
M= 101.5% if X̅>101.5%
for 10 tablets

Hi Hana81,

There is a way for Empower to do this using several custom fields and its explained from the Waters Informatics 2018 show, its too long to explain here so I will attach the guide via PM. Please be aware though that there are a LOT of custom fields required for it to work but if its done correctly it should save loads of time.

Hi Hana81,

There is a way for Empower to do this using several custom fields and its explained from the Waters Informatics 2018 show, its too long to explain here so I will attach the guide via PM. Please be aware though that there are a LOT of custom fields required for it to work but if its done correctly it should save loads of time.

Please remember that long costum field calculation formula take more time to calculate result. We made this formula in our company, but calculation for 10 tablets, deviation from 2 standards ect can take till 5 minutes processing.

Yes that's very true, but its still probably quicker than transcribing data into Excel.

Im afraid I cant attach the document. Look up Waters Informatics 2018 and the article Content Uniformity to see it.

as seen in Waters forums:
Here's how I've handled it-
USP_AV: ABS(-1*Ave_PercentClaim+M)+k*SD
L2Range: GTE(PercentClaim,(0.75*M))&LTE(PercentClaim,(1.25*M))
this is a calculated boolean where 0 translates to Outside L2 (25) Range and 1 translates to Within L2 (25) Range (so it's telling you whether there's any point to trying 20 more units if AV>15)
M: GT(AVE_PercentClaim,101.5)*101.5+LT(AVE_PercentClaim,98.5)*98.5+RANGE(AVE_PercentClaim, 98.5, 101.5)*AVE_PercentClaim
SD: SAME.%..%RSD(PercentClaim)*Ave_PercentClaim/100
k: boolean function that defaults to 0 (which translates to 2.4, and 1 translates to 2)

I'll assume users of this will already have appropriate dependent CFs corresponding to PercentClaim, AVE_PercentClaim etc.

as seen in Waters forums:
Here's how I've handled it-
USP_AV: ABS(-1*Ave_PercentClaim+M)+k*SD
L2Range: GTE(PercentClaim,(0.75*M))&LTE(PercentClaim,(1.25*M))
this is a calculated boolean where 0 translates to Outside L2 (25) Range and 1 translates to Within L2 (25) Range (so it's telling you whether there's any point to trying 20 more units if AV>15)
M: GT(AVE_PercentClaim,101.5)*101.5+LT(AVE_PercentClaim,98.5)*98.5+RANGE(AVE_PercentClaim, 98.5, 101.5)*AVE_PercentClaim
SD: SAME.%..%RSD(PercentClaim)*Ave_PercentClaim/100
k: boolean function that defaults to 0 (which translates to 2.4, and 1 translates to 2)

I'll assume users of this will already have appropriate dependent CFs corresponding to PercentClaim, AVE_PercentClaim etc.

Way too late to this but I'm in the same position at my workplace as those previously. I've got a bit of experience with simple CFs but nothing this complex.

@DR how did you actually set up the function for k? This is probably a dumb question but I'm trying to generate a CF that will total the number of samples with a common CF, possibly Label but more likely a locally created one called Batch_Number. I keep coming back to something along the lines of:

EQ(Sum(Batch_Number(SAME)))

But obviously am getting the function(s) and Field the wrong way around and I can't for the life of me figure it out. I've separately reached out to Waters themselves after trying to find the Waters Inform 2018 conference docs someone referred to, but these seem to be inaccessible now.

Fingers crossed there are still people active on this thread!

k is a boolean that defaults to 0 and can be set to 1. 0 translates to 2.4, 1 is translated to 2.
For CU runs, k is left at default value of 2.4 for n=10, can be changed to 2 if n=30 (in which case, a process only sample set is being used to process runs of 10 and 20 concurrently). I think it comes out as a required column with the header "n=10 (default) or 30 (enter 1)".
It has been a minute. Hope this helps or that a current Empower CF writer can finish this...