Bioequivalence and Bioavailability Forum

Sample Size from Interaction study [Power / Sample Size]

posted by Helmut  – Vienna, Austria, 2012-05-10 18:42 (5145 d 11:32 ago) – Posting: # 8557
Views: 6,980

Dear John!

❝ Is it possible to get an estimate of the intrasubject CV from a single dose design drug interaction study?

Yes.

❝ I reviewed your presentation on sample size and you mentioned that CV can be obtained from Cave at steady state?

I’m not a native speaker of English. To me as a certified cave diver “Cave at steady state” sounds funny.

I meant the Latin word cave. Generally PK interaction studies are performed in steady state (FDA, EMA). With a few exceptions^* variance in steady state is lower than after a single dose. If you plan a single dose study based on the MD’s CV, your sample size likely will be too low.

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• Van Hoogdalem EJ, Terpstra IJ, Krauwinkel WJJ, Volkers-Kamermans NJ, Baven ALM, and JSC Verschoor
  Multiple dose bioequivalence study with josamycin propionate, a drug with highly variable kinetics, in healthy volunteers
  Int J Clin Pharmacol Ther 1996;34(5):202–7
  PMID 8738856

—
Dif-tor heh smusma 🖖🏼 Довге життя Україна! 
Helmut Schütz


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Complete thread:

• Sample Size from Interaction study jag009 2012-05-10 16:14 [Power / Sample Size] 
  • Sample Size from Interaction studyHelmut 2012-05-10 16:42
    • Sample Size from Interaction study jag009 2012-05-10 19:39
      • Uncertainty of CVs; AUC72 - actual vs. nominal time Helmut 2012-05-11 15:13
        • Uncertainty of CVs; AUC72 - actual vs. nominal time jag009 2012-05-11 16:36
          • Uncertainty of CVs; AUC72 - actual vs. nominal time Helmut 2012-05-11 17:35
            • Uncertainty of CVs; AUC72 - actual vs. nominal time jag009 2012-05-11 18:13