Excluding time points for lambdaZ [RSABE / ABEL]

posted by d_labes  – Berlin, Germany, 2012-10-09 11:33 (4189 d 05:15 ago) – Posting: # 9352
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Dear Helmut, dear FI!

❝ ❝ What if one concentration looks to be an analytical mistake(?), that confounds t1/2 in such a way that the slope increases...?

❝ ...

❝ Other options (?):


In this post I had claimed "I never have seen deficiency questions concerning the fit of the terminal phase of concentration time courses in my ~30 years career. Even if the 'fit' was done with only 2 points".
Say never never. :no:
Quite recently I got:

… The applicant should justify the calculation of the terminal rate constant for patient #xxx, reference/r.1, patient #yyy, test/r.2 …

(It was a replicate BE study in patients).
The questioned cases had in common that the last measured concentration was increasing compared to the preceding ones and doesn't fit into the linear part for the log-linear regression. To not grossly overestimate the terminal half-life in such situations it is my standard operation to act according to Helmut's first option above.

Seems some regulators opinion do not match mine.

Regards,

Detlew

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