Bioequivalence and Bioavailability Forum • Leads to a (pseudo-) period effect

Leads to a (pseudo-) period effect [Bioanalytics]

posted by Helmut – Vienna, Austria, 2019-09-19 17:33 (1817 d 15:35 ago) – Posting: # 20619
Views: 6,628

Dear Ravuri and dshah,

I’m the last person to stick to guidelines (if scientifically doubtful) but the EMA’s, FDA’, and ICH’s are pretty good ones.

❝ Can the study samples of same subject in more than single run for cross over design can be analysed i'e analysis of P1 samples and P2 samples can be carried out separately in two different runs? If yes, how it need to be justify to regulatory?

As always the guidance states “should be” not “have to be”. OK, why do you think it is necessary to analyze periods in different batches? Long washout and problems with stability? More information please.

❝ If we choose different run, then there is high possibility of getting slight different calibration curve equation and thus finally concentration for the unknown samples.

Correct so far.

❝ Thus it could have direct impact on BE.

Here you err, IMHO. Don’t get me wrong, I would analyze all samples in the same batch if ever possible as well (even staggered sampling times – not one period after the other). However, if Ravuri would have different responses in his approach, they would show up in the ANOVA as a period effect – which is automatically corrected for and thus not relevant in assessing the treatment effect.

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Helmut Schütz

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Complete thread:

Crossover: samples of p1 and p2 in different batches? Ravuri sindhura 2019-09-18 19:16 [Bioanalytics]
- Crossover: samples of p1 and p2 in different batches? dshah 2019-09-19 09:16
  - Leads to a (pseudo-) period effectHelmut 2019-09-19 15:33
    - Leads to a (pseudo-) period effect ? Ohlbe 2019-09-19 15:50
      - Leads to a (pseudo-) period effect ? Helmut 2019-09-19 15:59
        
        Leads to a (pseudo-) period effect ? nobody 2019-09-19 16:21
        
        Almost entirely OT Helmut 2019-09-19 17:22
        
        Almost entirely OT nobody 2019-09-19 17:46
        
        Completely OT Helmut 2019-09-19 18:08
        
        Leads to a (pseudo-) period effect ? dshah 2019-09-20 07:52
        
        Leads to a (pseudo-) period effect ? nobody 2019-09-20 08:00
        Run ≠ batch? Helmut 2019-09-20 09:42
        
        Run ≠ batch Ohlbe 2019-09-20 10:37
        Run ≠ batch? dshah 2019-09-23 07:43
        
        Run ≠ batch? nobody 2019-09-23 08:36
    - Leads to a (pseudo-) period effect Ravuri sindhura 2019-09-23 13:04