3 replies to this topic

[fang ke]

How to do the deconvolution if the PK profile presenting a double peak? Any ideas?

[Simon Davis]

Coco - can you give us some idea of the extent and timing of the second peak - do you know the cause ?

 

perhaps an example profile would help guide our suggestions

 

  Simon.

[fang ke]

Hi Simon! Sorry for the late response! I've attached the project file to the forum. It could noticed from the xy plot that the most of the in-vivo profile presented a double peak phenomenon. I'm not sure about the cause. Another problem is that the reference for deconvolution is a IR oral dose and after deconvolution the fraction of absorption goes up to 200%. I'm not sure if this Fabs is right. Can you give me some advice to solve the problem. Thanks in advance! Coco [file name=New_Project.phxproj size=6679832] /extranet/media/kunena/attachments/legacy/files/New_Project.phxproj[/file]

Attached Files

•  New_Project.phxproj   6.37MB   419 downloads

Edited by Simon Davis, 22 March 2017 - 11:17 AM.

[Simon Davis]

Coco, I've looked at your plots and I see the double peak is present at different times - I guess there is some unevenness in how the extended release formulation is breaking up/releasing the drug Firstly are you sure that the IR dose was really 5mg - i.e. the same as all your controlled release formulations? Because if you perform a simple NCA on the raw profiles you will see you are getting less than half the AUC with the IR formulations And if you look at the half-lives it is 2hours versus 15-20 for the extended release formulation Do you think you sampled the IR profile long enough - is there perhaps a second phase of the 'true' elimination that occurs after your last timepoint of 10 hours e.g. it is really a 2compartment model?

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Edited by Simon Davis, 22 March 2017 - 11:17 AM.