2012-05-07 09:40
(3222 d 16:10 ago)

Posting: # 8521
Views: 5,622

 how to use Loo Riegelman method and deconvolution [Dissolution / BCS / IVIVC]

Dear forum,

I really need your help about aplication of Loo Riegelman and deconvolution to calculate the fraction absorbed. I have spent so much time to understand about that, Please tell me the step by step calculation of those equation. Thank you very much.


2012-05-18 12:32
(3211 d 13:19 ago)

@ laili
Posting: # 8584
Views: 4,761

 how to use Loo Riegelman method and deconvolution

Dear Laili,

Loo-Riegelman PK model assumes two-compartment PK. I think you may need to refine your question a little as to what you need clarifying.
  1. What are you trying to achieve and with what source data?
  2. What software is your LR model implemented in?
I would, (working as I do for Pharsight :surprised:), suggest taking a look at the Numerical Deconvolution implemented in WinNonlin and Phoenix WinNonlin if you have access to these software as I've had much more comfortable results with this tool for extravascular administration. Nonetheless I understand that some people prefer the LR and WN models so these are implemented within the IVIVC module which is an additional purchase.

Phoenix (and WNL 5.x) have detailed example datasets and Guides;

C:\Program Files (x86)\Pharsight\Phoenix\application\Examples

to help step you through using these functions. And of course there is our own software forum (login required).


Edit: Extranet linked. [Helmut]

Senior Scientific Trainer, Certara™

2012-08-23 12:03
(3114 d 13:47 ago)

(edited by Ohlbe on 2012-08-23 14:22)
@ laili
Posting: # 9096
Views: 4,437

 how to use Loo Riegelman method and deconvolution

Hi Laili,
sorry for a late response but i think for loo-riegelman deconvolution you should have a look at book of Gibaldi and Perrier pharmacokinetics 2nd edition page no. 155- 162

provided parameters like
Ke or K10;

you can calculate by using following equations:-
Ke= (a*b)/K21;
K12= a+b-K21-Ke;

Hope it will work for you

Edit: Full quote removed. Please delete anything from the text of the original poster which is not necessary in understanding your answer; see also this post! [Ohlbe]

2020-07-16 13:31
(230 d 12:19 ago)

@ vjkumar
Posting: # 21712
Views: 562

 how to use Loo Riegelman method and deconvolution

Dear vjkumar
Thank you for the reference and method explanation for deconvulation using loo riegelman method.
But I have stucked somewhere at the last time point as per the example given in the reference.
The %Absorbed value calculated by me is not matching with the value given and calculated in reference for last time point only.
So I think I am missing some parts like any assumption or hypothesis for consideration during the calculation for last time point.
Please help me to solve the calculation for last time point.

Thanks and Regards
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