Back to the Top
Hi all, After intravenous (10mg/kg) and intraperitoneal (60mg/kg)
administration, pharmacokinetics of Drug A is best described by two-
compartment and three- compartment models respectively. What general
conclusions one can draw ?
Back to the Top
The following message was posted to: PharmPK
Hi All
The Pharmacokinetic of drug A best described by two compartment and
the third compartment observed by ip is absorption phase All the
best ..
Back to the Top
I am sorry for the mistake in my previous thread. My corrected
question is as below.
After intravenous (10mg/kg) and intraperitoneal (60mg/
kg)administration, pharmacokinetics of Drug A is best described by
three-compartmentand two- compartment models respectively. What
general conclusions one can draw ?Thanks
[Now you might have an issue with the absorption step masking
compartments. For example if ka is between two fast exponentials you
might not see them both in your analysis. I would try simultaneous
modeling of the po and iv data - db]
Back to the Top
I am not sure if it makes sense, but don't you think the model for ip
data must be the same as your model for iv data. Essentially, they are
supposed to be the same, may the absoprtion after ip is rate limited
masking the profile. I believe you could better fit a three
compartment model to the ip data as well. I appreciate if experts
correct me in case!!!,
regards,
Jagannath Kota
--
Jagannath Kota, PhD
Senior Scientist, Global PK/PD
Novartis Healthcare Pvt. Ltd.
D Block 8th floor, iLabs Centre,
Software Units Layout,
Madhapur/Hyderabad 500081
AP INDIA
Back to the Top
The following message was posted to: PharmPK
Dear Jagannath,
You wrote:
> I am not sure if it makes sense, but don't you think the model for
>ip data must be the same as your model for iv data. Essentially,
>they are supposed to be the same, may the absoprtion after ip is
>rate limited masking the profile. I believe you could better fit a
>three compartment model to the ip data as well.
Fitting a three-compartment model to the ip data alone will not solve
the problem, and it is likely that a reliable solution, with
'reasonable' and precise parameter estimates, will not be obtained.
And even if a good solution is found, the parameters may be quite
different from that after iv, so the interpretation is still
questionable.
As was suggested earlier by David Bourne (in a possibly unnoticed
comment between []) it is much better to fit the data simultaneously,
with the constraint that the PK parameters for ip and iv are the same,
with an additional absorption process for ip. However, also in this
approach we can be sure of a critical comment from Walt Woltosz!
best regards,
Hans Proost
Johannes H. Proost
Dept. of Pharmacokinetics and Drug Delivery
University Centre for Pharmacy
Antonius Deusinglaan 1
9713 AV Groningen, The Netherlands
Email: j.h.proost.at.rug.nl
[Hans, thanks for noticing ;-) and for Walter that absorption process
can be whatever is required - db]
Want to post a follow-up message on this topic?
If this link does not work with your browser send a follow-up message to PharmPK@boomer.org with "Compartmental analysis" as the subject | Support PharmPK by using the |
Copyright 1995-2011 David W. A. Bourne (david@boomer.org)