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RegisterPhoenix: What to do if pre-dose is greater than the peak conc [Software]
Hi,
Dont laugh....
I received a single dose conc-time dataset from a 50 subject PK study. The compound is endogenous so there was pre-dose conc in every subject. Samples were collection from pre-dose and up to 12 hours at predetermined intervals. I reviewed the conc-time dataset prior to dumping it into Phoenix to carry out the NCA analysis.
Issue: One subject has pre-dose conc being greater than the highest conc in post-dose. The PK profile is legit (conc increased, reached peak, and decreased overtime). Phoenix's NCA identified pre-dose as the Cmax with Tmax = 0 (of course!).
Question: Is there a way to set up NCA in Phoenix such that the routine will exclude the pre-dose conc from being identified as Cmax? I goofed around and set up NCA to carry out the analysis as a mutiple-dose/steady state study but I still get the same result.
Thx
J
Dont laugh....
I received a single dose conc-time dataset from a 50 subject PK study. The compound is endogenous so there was pre-dose conc in every subject. Samples were collection from pre-dose and up to 12 hours at predetermined intervals. I reviewed the conc-time dataset prior to dumping it into Phoenix to carry out the NCA analysis.
Issue: One subject has pre-dose conc being greater than the highest conc in post-dose. The PK profile is legit (conc increased, reached peak, and decreased overtime). Phoenix's NCA identified pre-dose as the Cmax with Tmax = 0 (of course!).
Question: Is there a way to set up NCA in Phoenix such that the routine will exclude the pre-dose conc from being identified as Cmax? I goofed around and set up NCA to carry out the analysis as a mutiple-dose/steady state study but I still get the same result.
Thx
J
Complete thread:
- Phoenix: What to do if pre-dose is greater than the peak concjag009 2025-09-16 04:29
![[Mix]](https://static.bebac.at/img/mix.png "open in Mix view")
- Phoenix: Data please! Helmut 2025-09-16 21:51
Ing. Helmut Schütz