Partial Areas

Phoenix Certara Forums Phoenix WNL basics
1

Hi,

I would like to know how can obtain Cmax and tmax of the partial areas that can be obtained with Phoenix. I don’t find the option.

Thank you very much!

MR

2

Hi MR, i’m not sure I understand your question. Are you asking how to find the Cmax and Tmax of each partial Area you request? I’m not sure I’ve ever seen that requested before - it would be interesting for you to explain how you intend to use this information.

I think I would probably use a Data Wizard to bin the time-conc into the same groups as the partial areas you are requesting and then run descriptive stats on the conc in this group, the max would be the Cmax. Finally merge this back to the original time conc series to get the Tmax. However as I said I’ve never been asked for this in 15+years so that’s my first guess. If you explain a bit more about what you want to achieve then I might be able to suggest something a little more easier.

Simon

3

Hi Simon,

thank you for your fast answer. What I what to achieve is exactly what you understand. The Cmax and tmax for every partial area. I will try what you explain.

Thank you very much

Best regards,

MR

4

Here is the US usual exposure characteristics of a pharmacokinetic profile are Cmax, AUC and Tmax. For partial exposure metrics e.g. exposure for time scale 0-4 hr it is usual regulatory practice presently to calculate the only the AUC metric between 0 and 4 hours. However, that said, one can envisage instances of where having all 3 parameters for each exposure interval would be value. So if there is a convenient way of doing then it is of interest.

Angus

5

Hi Simon,

required for multiphasic and pulsatile release products according to the EMA’s MR-GL (Section 6.3. and esp. 6.8.1.1):

For multiphasic modified release products additional parameters to be determined include partialAUC, Cmax and tmax in all phases. The time point for truncating the partialAUC should be based on the PK profile for the e.g. IR and the MR parts respectively and should be justified and pre-specified in the study protocol.

In Europe I never have seen more than one cut-off, but the FDA requires for methylphenidate ER tablets three partial AUCs (though only the global Cmax).

My approach in PHX/WNL is similar to yours. :wink: