4 replies to this topic

[Charvi]

Hello All,

 

I am trying to simultaneously model plasma and tissue PK data from an animal study. While the Pop PK model works ok, no model fit lines are observed for tissue data, for example in IPRED, DV vs. IVAR plots. Model fits are visible for plasma data. Each animal contributes only one time point in the tissue profile. Is that the reason? In that case something should be visible for the DV, PRED vs IVAR plot? I know the model is taking into account all the tissues

as the parameter estimates etc. are obtained and so are CWRES and Pop DV vs Pred, Ipred etc.

 

Does Phoenix not generate the continuous Pred profile in Pop PK model for animals that have only one time point?

 

Thanks,

Charvi

[bwendt@certara.com]

Hi Charvi,

 

it would be very helpful if you can share the project file since we would need to examine the input data and the results to provide any help.

If this is confidential data, you can also send to our support team: support@certara.com, where the data will be handled strictly confidential.

 

Bernd

[Charvi]

Hi Bernd,

 

At this point, unfortunately I am unable to share any data.

 

Can you generally share any thoughts you may have, it is a standard animal study to collect PK samples from tissues over time -with each animal contributing one time point (because of terminal sampling).

I understand, if this is too general to provide a meaningful feedback.

 

Thank you for your help and quick response, much appreciated.

 

Regards.

Charvi

[bwendt@certara.com]

Hi Charvi,

 

if you have only one time point per animal the software cannot provide any fit lines since there need to be at least two time points to show a line. However, the Residuals worksheet does contain the data:

 

 

What you can do to see the fit lines is to send the residuals worksheet to an XY-Plot object where you can omit the subject code to see some connecting lines, like PRED, DV vs IVAR:

 

 

 

Hope, this helps.

 

Bernd

[Charvi]

Hi Bernd,

 

This is perfect. Works out.

 

Many Thanks,

Charvi