Back to the Top
Dear group
I was trying to use WinNonlin to perform deconvolution of a data set.
I had gone through the online winnonlin toolbox help. When I am
entering oral data into WinNonlin it is asking for A and alpha values.
How to compute A and alpha values and can numerical deconvolution be
done through excel also? Could you please give some basic idea about
numerical deconvolution calculations and concept. It will be helpful
if it is explained with the help of an example.
Best regards
radhika
Back to the Top
The following message was posted to: PharmPK
Hi Radhika,
If you are deconvoluting oral data against an intravenous response (to
simulate oral absorption) in WinNonlin, you will need to enter the IV
response as coefficients and exponents. The oral data can then be
entered as
the measured values.
If you are deconvoluting oral (slow release) against an oral solution
(to
simulate in vivo dissolution), you will need to fit an exponential
model to
the oral (solution or IR) data to obtain the coefficients and exponents
required for the deconvolution analysis in WinNonlin.
If you can't fit an exponential model to the oral data you can try
numerical
deconvolution using PCDCON. However, you may find that the numerical
approach is unstable.
Details of where to obtain PCDCON and examples of deconvolution
analyses can
be found in: BRINDLEY CJ. Practical aspects of deconvolution.
Pharmacokinetics in Drug Development (Ed: Bonate PL and Howard D). AAPS
Press, Alexandria, VA, 2004.pp 479-499
Best Regards,
Charlie
Back to the Top
Dear radhika,
you can first fit you intravenous data to a defined compartmental
model (I suppose 1 comp in your example) to obtain PK parameters (A
and alfa values in you example), then you can easly apply these PK
parameters to deconvolve other profiles obtaining for example
absorption profiles. Take care to use the correct dose for both
modeling (fitting) and deconvolution.
Yes, you can deconvolve numerically your data by other ways, but if
you have WinNonlin is really very easy to use this software.
It's possible to find some suggestions about deconvolution WinNonlin
Online Help by typing "Deconvolution methodology".
Best regards
Stefano
--
Dr. Stefano Porzio
PK/PD Scientist
Merck Serono Research
Meck Serono S.A.
RBM S.p.A. - Istituto di Ricerche Biomediche "A. Marxer"
Via Ribes 1
10010 - Colleretto Giacosa (TO), Italy
E-Mail stefano.porzio.at.merckserono.net
Back to the Top
The following message was posted to: PharmPK
Dear Radhika,
As Charlie and Stefano have already indicated, typically you could
obtain these values of A and alpha from a previous modelling of the,
e.g. IV, reference profile. These values are slope and intercept of this
line.
I would also draw your attention to the extended capabilities
available in our IVIVC module for WinNonlin that was released last year,
more details can be found on our website;
http://www.pharsight.com/products/prod_IVIVC_home.php.
You could also consider one of our forthcoming methodology and
software training courses -http://www.pharsight.com/training;
Best regards,
Simon.
--
Simon Davis
Senior Scientific Consultant
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 "WinNonlin Data entry for Deconvolution of oral dose" as the subject | Support PharmPK by using the |
Copyright 1995-2011 David W. A. Bourne (david@boomer.org)