**5. Conclusions**

A PPK model for tiropramide was developed on the basis of PK data for healthy Korean men in this study. The plasma concentration profiles for tiropramide were described well by a two transit absorption phase-one compartment model with an absorption lag time. The total protein was identified by significant covariates of CL/F and V/F for tiropramide, and their correlation was finally reflected in the PPK model of tiropramide. On the other hand, no significant correlation was found between genetic information such as *ABCB1*, *CYP2D6*, *OCT2*, *PEPT1*, and the PK parameters of tiropramide. To the best of our knowledge, this is the first time a PPK model has been studied for tiropramide, and it is expected to be a valuable resource for future studies (such as in clinical use, as well as dose control and formulation development).

**Supplementary Materials:** The following are available online at http://www.mdpi.com/1999-4923/12/4/374/s1, Figure S1: Normalized prediction distribution error (NPDE) for the final model.

**Author Contributions:** Research idea planning, S.-H.J., J.-H.J., and Y.-B.L.; method planning, S.-H.J. and J.-H.J.; method and data validation, S.-H.J. and H.-Y.C.; literature search, S.-H.J.; investigation, S.-H.J. and J.-H.J.; data analysis and modeling, S.-H.J. and J.-H.J.; original manuscript writing, S.-H.J. and J.-H.J.; review and editing of manuscript, S.-H.J., J.-H.J., H.-Y.C., and Y.-B.L.; supervision, Y.-B.L. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

**Conflicts of Interest:** The authors declare that they have no conflicts of interest relevant to this study.
