weiguo2122
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2025-01-13 21:19
(30 d 14:33 ago)

Posting: # 24339
Views: 570
 

 Issue with PBE Calculation when Stage = 1 [Regulatives / Guidelines]

FDA “Draft Guidance on Budesonide” part 5, provides Recommendation Related to the Population Bioequivalence (PBE) Statistical Analysis Procedure (Step 3):

a. If SigmaR is greater than 0.1, the reference-scaled procedure should be used.
b. If SigmaR is less or equal to 0.1, then the constant-scaled procedure should be used.

However, when stage (m) is 1, SigmaR cannot be defined because the calculation for MSWk cannot proceed when m = 1 (see formula for MSWk in the guidance).
[image]
[image]

What approach should be used to calculate PBE when m = 1? Are there any alternative methods or approaches recommended in this scenario?

I have attached formula from Draft Guidance on Budesonide for reference.

Thanks for replying and suggesting!
ElMaestro
★★★

Denmark,
2025-01-13 22:08
(30 d 13:44 ago)

@ weiguo2122
Posting: # 24340
Views: 504
 

 Issue with PBE Calculation when Stage = 1

Hello Weiguo2122,


❝ What approach should be used to calculate PBE when m = 1? Are there any alternative methods or approaches recommended in this scenario?



When m=1 you have a between units variation (MSB = Mean Square Between) but you do not have a within-unit-variation (MSW = Mean Square Within). A mean square is a variance. The square root of a variance is a standard deviation. You see, at m=1 the entire right-hand side of whatever is under the square root sign disappears.
So, at m=1 the stdev for ref is the square root of MSB for that formulation. :-)

Pass or fail!
ElMaestro
weiguo2122
☆    

2025-01-15 21:45
(28 d 14:07 ago)

@ ElMaestro
Posting: # 24341
Views: 418
 

 Issue with PBE Calculation when Stage = 1

Hi ElMaestro,

Thank you for your reply. Based on your suggestion, I have been working with a set of code;-):cool:


Edit: Full quote removed. Please delete everything from the text of the original poster which is not necessary in understanding your answer; see also this post #5! [Ohlbe]
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