Chromatography Forum

Hi ,

More questions on Empower 2 :

Anybody using custom fields to calculate Content unifomity as per USP 905?
Also Dissolution as per USP 711 (mass and volume correction if possible)?
Also what is the usual procedure for checking custom fields, if any (privilege level lock,test scripts,manual check, excel result comparison)

Thanks

Hi ,
After a number of hours I think I have the custom field field for Content uniformity, see below :
Any ideas how this could be simplfied would be great ,, also any ideas on dissolution mass and volume custom fields would be appreciated,, not sure if ti is possible in Empower though :

EQ(CU_TEST,10)*(GT((%.%.%.SUM(Content_X_U*EQ(CU_TEST,10))/10)
,101.5)*(((%.%.%.SUM(Content_X_U*EQ(CU_TEST,10))/10)-101.5)+2.4*
CU_STD_DEV)+LT((%.%.%.SUM(Content_X_U*EQ(CU_TEST,10))/10),98.5)
*((98.5-(%.%.%.SUM(Content_X_U*EQ(CU_TEST,10))/10))+2.4*CU_STD_DEV)+
RANGE((%.%.%.SUM(Content_X_U*EQ(CU_TEST,10))/10),98.5,101.5)*2.4*
CU_STD_DEV)+EQ(CU_TEST,11)*(GT((%.%.%.SUM(Content_X_U*
EQ(CU_TEST,11))/10),101.5)*(((%.%.%.SUM(Content_X_U*EQ(CU_TEST,11))
/10)-101.5)+2.4*CU_STD_DEV)+LT((%.%.%.SUM(Content_X_U*
EQ(CU_TEST,11))/10),98.5)*((98.5-(%.%.%.SUM(Content_X_U*
EQ(CU_TEST,11))/10))+2.4*CU_STD_DEV)
+RANGE((%.%.%.SUM(Content_X_U*
EQ(CU_TEST,11))/10),98.5,101.5)*2.4*CU_STD_DEV)+
EQ(CU_TEST,12)*(GT((%.%.%.SUM(Content_X_U*EQ(CU_TEST,12))/10),101.5)
*(((%.%.%.SUM(Content_X_U*EQ(CU_TEST,12))/10)-101.5)+2.4*CU_STD_DEV)+
LT((%.%.%.SUM(Content_X_U*EQ(CU_TEST,12))/10),98.5)*((98.5-(%.%.%.SUM(Content_X_U*EQ(CU_TEST,12))/10))+2.4*CU_STD_DEV)+
RANGE((%.%.%.SUM(Content_X_U*EQ(CU_TEST,12))/10),98.5,101.5)
*2.4*CU_STD_DEV)

Pretty cool. So does it work?

For dissolution we don't use the empower custom fields as this would be hard to implement.
We export all our dissolution results to a txt file, and then run a script to report our results (raw data, volume corrected, plots, and even conclusion).
On the other hand, this may be harder to validate....

Ace

Hi Eldred, well had some teething problems ,, and explaining the formula and custom field to our quality department was a struggle,,but overall it works ok.
Disappionting to hear no dissolution custom fields are been used,, maybe shows the limitations of Empower compared to other CDS out there.

....
maybe shows the limitations of Empower compared to other CDS out there.

Empower has a dissolution option which implements dissolution profiles, so you don't need custom fields, but it's an option, so this will be an additional cost.
There are people who use customfields to calculate dissolution results, do a search on this forum and you will find it.

Ace

As a user of the dissolution macro option in Empower 2, I must say that it works well and is not difficult to use or explain.

Also, I strongly suspect that the custom field above (for CU) will crash - it's just too long to be reliable (it has been posted here before, I showed it to a Waters person who works with custom fields a lot and he is the one who said it will probably crash due to its length).

What I'd be interested in (and I'm waiting for Waters to get back to me with a better solution) is a macro or shorter custom field for CU acceptance values.

@DR: the Empower toolkit isn't an option?

@DR: the Empower toolkit isn't an option?

We have disso, but not toolkit.

What I'd be interested in (and I'm waiting for Waters to get back to me with a better solution) is a macro or shorter custom field for CU acceptance values.

I would be curious to know what they suggest.

Thing is CU is a bear of a test to do not too sure how much simplification of the math one can do. Though, I could see the macro approach to offload the math elsewhere.

i tried to calculate the Dissolution without Dissolution addon software from waters
Calculation:


1. Standard Concentration Calculation (Concentration of drug).

mg/mL

2. drug Concentration is individual Vessel.

mg/mL

3. Amount of drug in individual Vessel at specific time point.


Sampling Time (Hr) (t) Time point No. (n) Amount of drug at specific time point (X)
0.25 1 Cn x [900-(n-l)xV]
0.50 2 Cn x [900-(n-l)xV] + V x (C1)
0.75 3 Cn x [900-(n-l)xV] + V x (C1+C2)
1.00 4 Cn x [900-(n-l)xV] + V x (C1+C2+C3)
2.00 5 Cn x [900-(n-l)xV] + V x (C1+C2+C3+C4)
2.25 6 Cn x [1000-(n-l)xV] + V x (C1+C2+C3+C4+C5)
2.50 7 Cn x [1000-(n-l)xV] + V x (C1+C2+C3+C4+C5+C6)
2.75 8 Cn x [1000-(n-l)xV] + V x (C1+C2+C3+C4+C5+C6+C7)
3.00 9 Cn x [1000-(n-l)xV] + V x (C1+C2+C3+C4+C5+C6+C7+C8)
4.00 10 Cn x [1000-(n-l)xV] + V x (C1+C2+C3+C4+C5+C6+C7+C8+C9)

4. % drug Dissolve at specific time point


Cstd=Standard Concentration in mg/mL
Stdwt=Weight of Standard
VStock=Volume of Stock Standard Solution used to prepare final standard solution.
P=Purity of Standard
CF=Conversion Factor
Cn=Sample Concentration at specific (nth) time point
Asample=Area of Sample
Astd=Average Area of System Suitability standard
V= Volume Removed at each time point i.e.3 mL
n= Time point number
X=Amount of drug at specific time point
LC=Label Claim


1V1..(Amount)+2V1..(Amount)+3V1..(Amount)+4V1..(Amount)+5V1..(Amount)+6V1..(Amount)+7V1..(Amount)+8V1..(Amount)+9V1..(Amount)+10V1..(Amount)
1V2..(Amount)+2V2..(Amount)+3V2..(Amount)+4V2..(Amount)+5V2..(Amount)+6V2..(Amount)+7V2..(Amount)+8V2..(Amount)+9V2..(Amount)+10V2..(Amount)
1V3..(Amount)+2V3..(Amount)+3V1..(Amount)+4V3..(Amount)+5V3..(Amount)+6V3..(Amount)+7V3..(Amount)+8V3..(Amount)+9V3..(Amount)+10V3..(Amount)
((Amount*Media_Volume)+(CFV2*Sample_Volume))/Label_Claim*100
((Amount*Media_Volume)+(CFV3*Sample_Volume))/Label_Claim*100

We have disso, but not toolkit.

What I understand from Waters is that everybody has the toolkit, but not the information CD about how to work with this.

For example if you reference the Empower toolkit dll's in a VBA project, you are able to login in Empower, select the results in your empower project, and transfer them in an Excel sheet.
If you add some VBA programming to setup your calculations, you're done.


HTH

Ace

^ That is correct ...

... which I sort of think is a raw deal. Everyone has the toolkit. Want to know how to use it? Sorry, purchase a developers license from us and we will gladly supply you with the manuals.

As a result, I have figured out how to do disso (not just the calcs, but the spec application at the desired stage for the desired dosage form) and content u from within Empower.

On account of recent Excel problems on another thread of mine, I'm not very keen on offloading to anything anymore.

Hi. I saw the formula for CU calculation, but it's a bit confusing for me, could you please explain how to create CU_TEST, CU_STD_DEV? It is an Enum Type custom field?

I would recommend not using the equation posted earlier in this thread. Empower will not be able to handle the calculation in one custom field.

I have successfully implemented content uniformity and dissolution calculations to many of my clients around the world.

If this is something you are looking to do please send me a message. This is something that I charge for. I have my own personal license for Empower and can deliver a project to you with all the calculations for use in your database.