Dear All, Greetings! Kindly check wheteher I have handled the software correctly for IVIVC, I have attached my IVIVC project. My Data: In-Vitro: Test A ( 0-12 hrs); Test B (0-12 hrs) In-Vivo: Reference ( 0-48 hrs) ( 37 time points) Test A ( 0-48 hrs) ( 25 time points) Test B ( 0-48 hrs) ( 25 time points) While performing IVIVC, I have taken the In-Vivo data till 12 hrs time points only, Was that correct? I was confused while selecting the model in In-vitro tab, which model should be selected? Kindly guide me in this. Thanks & Regards Anu Jaswal [file name=IVIVC.phxproj size=5703390]Certara | Drug Development Solutions (5.44 MB)
Anu, there are a few things that I think you need to look at; first let’s look at your data; 
You see you have a very strange profile in vivo for Sub 1, Form A and if you drill down into the original work sheet it looks like you’ve copy-pasted time over the conc, I would suggest you import data from your source worksheet to avoid these sort of errors in future. 
Then you said you had more data in vivo than 12 hours but you don’t present this - I don’t understand why. If you have the data you should keep it in the model building. Lastly for now I think your dissolution experiments could be improved on with more sampling and for longer so you can get a better estimate of Finf. Currently your Hill model is giving some pretty weird values when you hink Finf should be nearer 1. Formulation Parameter Units Estimate StdError CV% A FINF 1.852947 1.4230953 76.801728 A MDT 9.9962975 32.28197 322.93927 A B 0.47293442 0.24114752 50.989632 A TLAG 0 A INT 0 B FINF 3.3982849 4.990028 146.8396 B MDT 39.981038 104.7663 262.03998 B B 0.85950559 0.24293248 28.264212 B TLAG 0 B INT 0 I have refitted the diss data against 3 models with Finf fixed to 1 and perhaps I would go with Makoid Banakar with your current dissolution data but I would also recommend re-running those. Item Form DissHill DissMakoidBanakar DissWeibull AIC A -20.80863 -34.11575 -24.29333 AIC B -18.46907 -30.31884 -22.26503 Simon [file name=IVIVC_Pregabalin.phxproj size=6676281]Certara | Drug Development Solutions 
IVIVC_Pregabalin.phxproj (6.37 MB)
Hi Simon, Thank you so much for your esteemed reply. Point taken ( I would suggest you import data from your source worksheet to avoid these sort of errors in future.) While taking the in-vivo data till 48hrs the % predicted errors were giving strange results, Thats why thought to make in-vivo data too for 12hrs, since in-vitro data is for 12 hrs. Do you think this thought process was wrong? Thanks & Regards Anu Jaswal
Hi Anu, I’ve taken some time to put together a few more comments regarding your experiment 1) at the moment there is nothing in the dissolution profile to suggest the second peak you’re observing invivo. a) I’d sample the the in vitro for longer (to reach F=1 or at least until it levels off) b) sample a lot more frequently. c) sometimes the QC dissolution protocol can be modified to be something that is more physiologically relevant/relatable. 2) I would use ALL the in vivo data 3) You need a better reference to perform your deconvolution with, ideal would be IV, perhaps you can get this from the literature, but an Oral solution or Immediate release would also work. It’s worth clarifying the terms we’re using; a) REFERENCE is the formulation used to deconvolve the TEST formulations, it should be the simplest possible (I.e. IV bolus) to most easily describe the elimination. b) TARGET is the formulation or profile you are trying to match If you can’t get a good ref then you could perhaps use Wagner-Nelson (or Loo-Riegelmann if 2-com) to perform the deconvolution instead Simon