Skip to main content

Research Repository

Advanced Search

A Population-based PBPK Model for the Prediction of Time-Variant Bile Salt Disposition within GI Luminal Fluids

Stamatopoulos, Konstantinos; Pathak, Shriram; Marciani, Luca; Turner, David


Konstantinos Stamatopoulos

Shriram Pathak

Luca Marciani

David Turner


In vivo studies have shown cyclic bile salt (BS) outputs during fasting whereas higher amounts have been observed in fed states. This leads to fluctuations of intestinal BS concentrations ([BS]) that can affect the rate and extent of absorption of lipophilic drugs in particular. However, most PBPK models use fixed val-ues of [BS] in fasted and fed states albeit with different values in different regions of the GI tract. During fasting, there is a relationship between gallbladder volume (GBV) and the phase of the Interdigestive Mi-grating Motor Complex cycle (IMMCc), showing cyclic GBV changes with periodic filling and emptying. This relationship is also affected by the origin of the IMMCc (antral or duodenal). In fed states, meta-analysis indicated that GB residual volume (% of fasting maximum) was 46.4 ±27 %CV and 30.7 ±48 %CV for low- and high-fat meals respectively. The corresponding values for the duration of the emptying phase were for low fat meals 0.72h ±1%CV and for high fat meals 1.17h ±37%CV. The model, the Ad-vanced Dynamic Bile Salt Model (ADBSM), was built bottom-up and its parameters were not fitted against in vivo measurements of [BS]. It involved update of the dynamic luminal fluid volumes model based on meta-analysis of available imaging data. The ADBSM is incorporated into the Simcyp® (v18r2) PBPK simulator. The model predictivity was good (within 1.25 fold error for 11/20 of the clinical studies) and was assessed against clinical studies of luminal [BS] that provide only the type of meal (i.e., low- or high-fat), the timing of the meal and/or water intake events, and the number and age range of the study participants. The model is also an important component of models capturing enterohepatic recirculation of drug and metabolite. Further work is required to validate the current model and compare to simpler models with respect to drug absorption, especially of the lipophilic compounds.

Journal Article Type Article
Publication Date Apr 6, 2020
Journal Molecular Pharmaceutics
Print ISSN 1543-8384
Electronic ISSN 1543-8392
Publisher American Chemical Society
Peer Reviewed Peer Reviewed
Volume 17
Issue 4
Pages 1310-1323
APA6 Citation Stamatopoulos, K., Pathak, S., Marciani, L., & Turner, D. (2020). A Population-based PBPK Model for the Prediction of Time-Variant Bile Salt Disposition within GI Luminal Fluids. Molecular Pharmaceutics, 17(4), 1310-1323.
Keywords Molecular Medicine; Drug Discovery; Pharmaceutical Science
Publisher URL
Additional Information “This document is the Accepted Manuscript version of a Published Work that appeared in final form in Molecular Pharmaceutics copyright ©American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see