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Hi All
I was trying to use winnonlin to perform deconvolution of a data set.
In that case we would have the i.v data and the per-oral data how do I
enter in winnonlin to perform a deconvolution of the oral data. I went
through the manuals however nowhere it specified the way the data is to
be entered for this situation. Could some highlight on this issue.
Thanks with appreciation.
manish
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Hi Manish:
You can look up the WinNonlin online help under WinNonlin
toolbox/deconvolution.
First, you will need to fit the iv data with a multiple exponential
function to run the deconvolution on the po data. Hope this is helpful.
Best regards,
Sam Liao, Ph.D.
PharMax Research
199 Pierce Street,
Suite 817,
Somerset, NJ 08873
phone: 201-9882043
efax: 1-720-2946783
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Hi Manish,
You have to perform a PK-Compartmental analysis of your IV data to get
your
rate constants between the comprtments. Then, using your peroral data
you can
select standard deconvolution wizard in winnonlin and enter the
parameters.You
have to specify your unit impulse response parameters. The exponential
terms
(Alpa, beta, A, B) in your unit impulse response will be determined by
the
number of compartments that you can describe the disposition of the
drug after
IV administration. Hope this helps.
Ayyappa
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Dear Manish,
Last week we held our North American User Group Meeting and next
week we hold our European meeting in Sardinia
http://www.innaphase.com/docs_events/UGM/2004/ugm_2004.html
One of the presentations demonstrated the simplicity,
flexibility and expandability of using Kinetica's templates to perform
exactly the sort of calculation methods you are enquiring about.
Because all our templates come with sample data you can see exactly how
they are meant to be used, a brief summary follows;
To show a step-by-step process of building an IVIVC template using
Kinetica
To provide a rationale for using specific methods in Kinetica library to
build the template
To build a regression analysis for a simulated drug tablets with three
different release types: slow, intermediate, and fast.
To validate the IVIVC model
To predict time concentration profiles for the new formulation (extended
release tablets) using the IVIVC model
If that sounds interesting please drop me a line to see how
Kinetica performs using our demo version of Kinetica 4.3, available at;
http://www.innaphase.com/support_downloads_kinetica.html
You do not need to download the client, just the "4.3 update.zip";
and you will have to contact me to for the password to unzip this.
Ass well as IVIVC; NCA, compartmental and population analyses
are all possible using the pre-built templates and models, as well as a
graphic designer to build your own. We also provide packages to assist
validation.
Best regards,
Simon.
Simon Davis
European Technical Support Scientist
Cell phone : +44 7980 832 666
Telephone : +44 1494 582 080
Facsimile : +44 1494 582 454/+1 801 991 7145
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Dear Manish,
One question you might ask is - why are you trying to deconvolute in the
first place?
If you're trying to understand how in vitro dissolution correlates with
F(t) (systemic availability vs time), that's one thing. If you're trying
to understand (and correlate) how in vivo release differs from in vitro
dissolution-time, that's another.
With our GastroPlus(TM) software, you can have it any way you like. You
can deconvolute the in vivo release directly, from which the F(t) is a
result after any combination of regional absorption and metabolism
(linear or highly nonlinear). This is a more direct approach to relating
what happens in an in vitro dissolution experiment with what happens in
vivo. It yields the same F(t) as any other method given the same
pharmacokinetic parameters (there is only one solution for F(t) for a
given set of PK parameters that will yield a particular plasma
concentration-time profile). But it has the advantage that it enables
you to accommodate any combination of saturable transport (influx and/or
efflux), gut metabolism, liver metabolism, renal clearance, lumen
degradation, release/dissolution/precipitation, etc. - and you don't
ever have to write any equations.
You can get correlation functions for any combination of Fa(t), F(t), in
vitro dissolution, or in vivo release/dissolution.
Best regards,
Walt Woltosz
Chairman & CEO
Simulations Plus, Inc. (AMEX: SLP)
1220 W. Avenue J
Lancaster, CA 93534-2902
U.S.A.
http://www.simulations-plus.com
Phone: (661) 723-7723
FAX: (661) 723-5524
E-mail: walt.-at-.simulations-plus.com
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