joao.reis
☆

Portugal,
2022-03-24 17:35
(365 d 05:01 ago)

Posting: # 22869
Views: 1,100

## Numerical Con­vo­lu­tion [Dissolution / BCS / IVIVC]

Hello dear bioequivalence fellas,

I'm starting my journey testing IVIVC and I've bumped into a wall which is really slowing down my progress.

I'm testing an IVIVC model I've found in the literature which has a high predictive power.
I'd like to predict the in vivo PK profile of my formulation (Extended Release) from which I have biorelevant in vitro dissolution data (the same medium, volume, rpm as the one used in the paper). I also have in vivo data from an IR formulation which I guess it can be used as the UIR function.

I was able to predict the fraction absorbed / time from my formulation using the IVIVC model and the in vitro data mentioned above. I've also fitted equations (Rsquared > 95%) to both my UIR function and fraction absorbed data (Don't know if it helps). Nonetheless, I have little to no clue of how to solve the convolution equation since I'm not a mathematician...

I have no access to WinNonlin nor to other specific software. Can anybody help me pointing on the right direction to move forward and predicting my in vivo PK profile?

Helmut
★★★

Vienna, Austria,
2022-03-24 17:50
(365 d 04:46 ago)

@ joao.reis
Posting: # 22870
Views: 920

## Numerical Convolution

Hi Joao,

IVIVC is not my cup of tea.

❝ I have no access to WinNonlin nor to other specific software.

I guess you have , right? If not, ask Nuno or Paulo for assistance.
Then try the package ivivc for R. If you have questions, post in the category R for BA/BE. Yung-jin Lee passes by regularly.

Dif-tor heh smusma 🖖🏼 Довге життя Україна!
Helmut Schütz

The quality of responses received is directly proportional to the quality of the question asked. 🚮
Science Quotes
dshah
★★

India/United Kingdom,
2022-03-24 18:10
(365 d 04:26 ago)

@ joao.reis
Posting: # 22871
Views: 980

## Numerical Convolution

Hello Joao. reis!
For IVIVC, or convolution approach, you can try a research article from Qureshi titled "In Vitro-In Vivo Correlation (IVIVC) and Determining Drug Concentrations in Blood from Dissolution Testing – A Simple and Practical Approach". It is giving example using one compartmental analysis which can also be extended to two compartmental analysis. For determining initial PK parameters, you can use tools like PKsolver or PCModFit(both are free).
For more complex deconvolution approach using wegnor nelson (for deconvolution), you can use Prof- J-M. Cardot's excel sheet.
Regards,
Divyen Shah
jag009
★★★

NJ,
2022-03-24 22:03
(365 d 00:32 ago)

@ joao.reis
Posting: # 22872
Views: 875

## Numerical Convolution

Hi,

Take a look at articles from Frieder Langenbucher might also help.
https://pubmed.ncbi.nlm.nih.gov/14602187/

J