ivivc for R

Development and validation are 2 critical steps in the evaluation of an IVIVC model.  In the first, the development of the level A IVIVC model is usually estimated by a two-stage process.(1) Deconvolution:  the observed fraction of the drug absorbed is estimated based on the Wagner-Nelson method.  IV, IR, or oral solution was attempted as the reference.  Then, the pharmacokinetic parameters will be estimated using a nonlinear regression tool or obtained from literature reported previously.  The IVIVC model is developed using the observed fraction of the drug absorbed and that of the drug dissolved.  Based on the IVIVC model, the predicted fraction of the drug absorbed is calculated from the observed fraction of the drug dissolved.  (2) Convolution: the predicted fraction of the drug absorbed is then convolved to the predicted plasma concentrations by using the convolution method.  In the second stage, evaluating the predictability of a level A correlation focuses on estimating the percent prediction error (%PE) between the observed and predicted plasma concentration profiles, such as the difference in pharmacokinetic parameters (Cmax, and the area under the curve from time zero to infinity, AUC∞). Here is a .pdf sample file for the plots. A sample text output file from ivivc for R is here. The reference that we used to develop ivivc for R can be downloaded from here.
   This package was performed together with several R packages.  "PKfit" package is used to fit the reference data such as IV, IR, or oral solution by fitting a one-compartment model.