Bioequivalence and Bioavailability Forum

Hi Suchit,

❝ As per latest published draft guideline "Bioequivalence Studies with Pharmacokinetic Endpoints for Drugs Submitted Under an ANDA" […] one sentence is there like The concentration data for the subject who vomited should be reported

❝

❝ Hence it is required to report concentration data of subject who had vomited for the USFDA studies

Correct.

❝ Valuable suggestions required

Suggestions about what? Simply follow the guidance.

BTW, in my CRO we always analyzed all samples.*
Justification: Although subjects who vomited (IR \(\small{\leq 2\times\widetilde{t_\textrm{max,R}}}\) and MR \(\small{\leq\tau}\)) were excluded from the comparison according to the protocol, their profile was informative. It’s always good to learn something. It turned out that – surprisingly more often than not – the effect was a minor one.

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• Even samples of dropouts (due to AEs) or withdrawals (due to ‘personal reasons’). Sometimes subjects don’t report AEs being afraid not to be recruited for other studies and withdraw consent instead. It might be that such a subject is a poor metabolizer leading to high concentrations… Good to know.
  One example was reported by Patrick et al. It turned out that the subject belonged to an extremely rare sub-population of ultra-slow metabolizers and his concentrations were 100 (‼) times higher than usual.
  
  Patrick KS, Straughn AB, Minhinnett RR, Yeatts SD, Herrin AE, DeVane CL, Malcolm R, Janis GC, Mar­ko­witz JS. Influence of Ethanol and Gender on Methylphenidate Pharmacokinetics and Pharmacodynamics. Clin Pharmacol Ther. 2007; 81(3): 346 53. doi:10.1038/sj.clpt.6100082. Free Full text.