Which Tmax will be considered for calculation of partial AUC0-Tmax?

Phoenix Certara Forums Phoenix WNL basics
1

Hi All,

I have to estimate partial AUCs i.e. AUC0-tmax, AUCtmax-24 and AUCtmax-tlast and definitions are provided below for your reference.

  • AUC0-tmax The area under the plasma concentration versus time curve from time zero to maximum concentration time point as calculated by linear up/log down trapezoidal method
  • AUCtmax-24 The area under the plasma concentration versus time curve from maximum concentration time point to 24 hour as calculated by linear up/log down trapezoidal method
  • AUCtmax-tlast The area under the plasma concentration versus time curve from maximum concentration time point to last measurable time point as calculated by linear up/log down trapezoidal method

Please suggest us which Tmax could be used for estimation of partial AUCs.

Sandeep… :slight_smile:

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In Phoenix WInNonlin, as in previous versions of WinNonlin, if Cmax is not unique then the first occurrence is designated Tmax.

You may find the project Helmut shared on the thread below a useful starting point;

https://support.certara.com/forums/topic/942-partial-aucs-phx64/

Simon.

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Namaste Sandeep,

see my post Simon linked above. Essentially it boils down to the question how you define tmax which you consider to be a relevant cut-off time point for the partial AUCs. Seems that you are aiming at Method #1 (which might be terrible). #3 is preferred by the FDA for IR products, and #4 by Health Canada. Which is your “target” agency? What does you protocol say?