Bioequivalence and Bioavailability Forum

Dear Helmut,

❝ Maybe of interest a sneak-preview of a presentation about repeating studies for the upcoming BioBridges.

I sneaked to the preview of the presentation about repeating studies - interesting topic.

After looking at slide 11, i started to be interested also in case with not bioequivalent formulations (related to Type I Error - incorrectly reject true null hypothesis of bioinequivalence, i.e. incorrectly conclude bioequivalence for not bioequivalent formulations). Just theoretical case with poor test formulation - not bioequivalent with reference, assumed true ratio 0.8 - to get power not more than 5 % (as TIE).
So (not suggested) scenario is to repeat bioequivalence study several times until the success and to see probability when "success" could happen.
    n      p
    1   0.0500
    2   0.0975
    3   0.1426
    4   0.1855
    5   0.2262
    6   0.2649
    7   0.3017
    8   0.3366
    9   0.3698
   10   0.4013
   11   0.4312
   12   0.4596
   13   0.4867
   14   0.5123
   15   0.5367
   16   0.5599
   17   0.5819
   18   0.6028
   19   0.6226
   20   0.6415
   21   0.6594
   22   0.6765
   23   0.6926
   24   0.7080
   25   0.7226
   26   0.7365
   27   0.7497
   28   0.7622
   29   0.7741
   30   0.7854
   31   0.7961
   32   0.8063
n ... Try No.
p ... Probability of BE Concluded
Note: p = 1 - 0.95^n (calculation is similar like with a dice, to roll at least one six from several tries, all tries have probability 5/6 to not achieve six, in case above probability is 0.95 to not achieve BE in one try).

Best regards,
zizou