IVIVC or not IVIVC? [Dissolution / BCS / IVIVC]
❝ Once I read your post, I tried to find the excel file with no luck. It's been a long time ago. Sorry about that. I think it should be not that difficult to re-create that excel file. As far as I can remember, the excel file was just used to validate Wagner-Nelson method used in ivivic for R. You should be able to find it from some textbooks, such as Shargel and Yu's Applied Biopharmaceutics & Pharmacokinetics. Even if you can access that excel file, it may not be helpful for you since you do not have iv data in your case.
Yes, it's may be simple. I tried to recreate the example that was in the article, but no success.
❝ Wagner-Nelson approach requires iv/solution/suspension data to calculate 'Kel' first, and then use 'Kel' to back-stripping the drug conc. vs time curve for oral dosage forms to get 'Ka' for each subject. If you really need Wagner-Nelson method, that should be very simple. You can dig in ivivc for R and find the file 'WagNel.R' from source tarball. If you had different sampling times for in-vitro and in-vivo, you can find another nice R package called Rivivc. Rivivc uses numerical convolution/deconvolution approach to establish ivivc. So it does not require same sampling times for in-vitro and in-vivo data. Please let me know if you are not familiar with R, although I do not think you need ivivc at all. I am very happy to help.
I'm not exactly familiar with R but I have friends that have friends that is. I will try this ones.
❝ See? Here is the question. One IR formulation and dissolution profiles with different pH media? You consider to establish ivivc for your case? I doubt it.
This is very sad.
❝ Again, if you do not have iv data for each subject, you cannot predict 'Ka' or 'Fabs' correctly. The value of 'Kel' should be estimated from the same subject. Otherwise, the result may not be reliable.
Did you think that I can use another method ? I say that because there is another work that was able to establish the correlation through GastroPlus. 10.1208/s12249-013-0016-4
He uses 2 biobatches to generate in silico data, but one of the biobatches wasn't BE with the reference drug. So, the IVIVC was made with just one biobatches based on different dissolution method.
❝ Did you imply that different sampling times (points) be used for in-vitro and in-vivo data in your study? If yes, look for Rivivc. However, even Rivivc requires iv/solution/suspension data. There should be no excel example for this, as far as I know.
Yes. But, as far as I read, this seems to be a commom thing. I think that Rivivc could help.
Perhaps I have to look at the IV data, not least because simulation software uses other particulars of the drug and its behavior in the body to generate the in silico data.
Thanks for all help!