2020-04-30 18:10
(141 d 20:56 ago)

Posting: # 21376
Views: 2,506

 Weibull method for Dissolution Similarlies [Dissolution / BCS / IVIVC]

Hello friends,

I am looking for validation of R vs DDSolver weibull method in dissolution comparison.

Let me explain you my points:

1. I have received FDA comment to validate DDSolver weibull method and re-submit the same results.

2. I have gone through all discussions and open forums. But I couldn't find R-Codes for DDSolver weibull method, specially alpha and beta calculation.

4. In SAS also it ask for IML package which we do not have.

Can anyone help me regarding the same?

I am unable to validate weibull method calculation of DDSolver.

Thank you.
Kaohsiung, Taiwan,
2020-04-30 18:31
(141 d 20:35 ago)

@ Jainee
Posting: # 21377
Views: 947

 Weibull method for Dissolution Similarlies

Hi Jainee,

I did get your e-mail messages sent from the Forum about this question few days ago. Sorry to forget to respond. But it is good to post your question here. Hope you can get more help from many guru of this Forum. I do not have any experience with DDSolver at all. Either dissolution comparison stuffs. Thus I don't think I can help. Could you contact the author(s) of DDSolver about your question? Good luck.

All the best,
-- Yung-jin Lee
bear v2.8.8:- created by Hsin-ya Lee & Yung-jin Lee
Kaohsiung, Taiwan http://pkpd.kmu.edu.tw/bear
Download link (updated) -> here

2020-05-01 07:37
(141 d 07:29 ago)

@ yjlee168
Posting: # 21381
Views: 900

 Weibull method for Dissolution Similarlies


I too have emailed to DDSolver developers Yong Zhang & Jianping Zhou. Awaiting for their response. Hope they are safe during this Pandemic.

We tried all R packages but not getting the similar output for weibull (dependent model of DDSolver).

Hope someone can guide on this from this forum.


2020-05-07 03:49
(135 d 11:17 ago)

@ Jainee
Posting: # 21403
Views: 777

 Weibull method for Dissolution Similarlies

When you have limited time on your side I will take the following approach

1. First take a standard drug dissolution data (Metoprolol) published in classic IVIVC papers by UMBC Natalie Eddington et. al during late 90s.

2. Use the published Metorpolol data or data available in the public domain (e.g. FDA website )and follow their outlined steps for constructing the Weibul plot applying one or two known tools (SingmaPlot, WinNonlin or Gastroplus) in addition to the DD scholar or R, then

3. Conduct a 3 or 4-way comparison of Weibull plot results to validate your DD Scholar output for metoprolol.

This comparison serves as a validation, and then repeat the exercise with your experimental data show results from your DD-scolar work compares well with reference technique.

WinNonlin IVIVC tool kit provides Model 602 as Weibul comparison.

The equation for Weibul given as

y(t) = Finf (1 - exp[-(t / MDT)b]) (ref: page 46 of 92 IVIVC help guide)

Most Importantly, A priori you have to define criteria for similar results between two methodologies (e.g. say No More than 10% difference to conclude no difference)

Hope this route helps your cause.


2020-05-10 11:35
(132 d 03:31 ago)

@ Achievwin
Posting: # 21412
Views: 691

 Weibull method for Dissolution Similarlies

Dear achiewin,

Thank you for your response.

I will try as per your guidance.


Edit: Full quote removed. Please delete everything from the text of the original poster which is not necessary in understanding your answer; see also this post #5[Helmut]
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