Evaluation of fasted state human intestinal fluid as apical solvent system in the Caco-2 absorption model and comparison with FaSSIF

Abstract

To date, the Caco-2 model is considered as the gold standard to predict intestinal drug absorption. Often, aqueous phosphate buffers are used as apical medium. The purpose of this study was to use fasted state human intestinal fluid (FaHIF) as apical solvent system to generate biorelevant permeability values for a series of 16 model drugs that can be used as reference data to critically evaluate fasted state simulated intestinal fluid (FaSSIF) as possible substitute medium. Caco-2 compatibility with FaHIF was achieved when 50mg/ml mucus was applied on top of the cells before adding the apical medium. The use of FaHIF as solvent system generated a broad range of apparent permeability values (Papp) for the series of model compounds. When Papp values obtained with FaHIF were compared to those obtained with FaSSIF, a strong correlation was observed (R=0.951). The use of FaSSIF in the absence of mucus did not significantly alter this correlation. For FaHIF, FaSSIF and reference phosphate buffer blank FaSSIF, a strong sigmoidal relationship was found between Papp and fahuman, illustrated by correlation coefficients of 0.961, 0.893 and 0.868, respectively. In terms of inter-subject variability, the use of FaHIF from different volunteers originating from two distinct age groups (18-25 years; 65-72 years) exhibited an average coefficient of variance (CV) of 30%. However, no age dependency in permeability could be observed. In conclusion, the data generated in this article justify the use of FaSSIF as biorelevant apical medium in the Caco-2 assay to accurately predict in vivo drug absorption. Also, the optimized mucus-containing Caco-2 model can be used in combination with intestinal fluid samples aspirated after drug administration to further investigate intraluminal drug and formulation behavior.

The Evaluation of In Vitro Drug Dissolution of Commercially Available Oral Dosage Forms for Itraconazole in Gastrointestinal Simulator With Biorelevant Media

“…The compatibility of Caco-2 cell monolayer against FaSSIF and/or HP-b-CD is controversial. 20,50,[52][53][54][55] Thus, Caco-2 cell monolayer integrity was checked by TEER values and lucifer yellow permeability in this study. As shown in Table 3, less than 15% of reduction of TEER and acceptable lucifer yellow permeability (<1 Â 10 À6 cm/s) indicated that Caco-2 cell monolayer kept its tightness in all tested groups.…”

Assessment of Passive Intestinal Permeability Using an Artificial Membrane Insert System

“…[32][33][34][35][36] Because these media are supplemented with biorelevant substances like taurocholate and lecithin, they are preferred over simple aqueous buffers. Wuyts et al 37,38 previously validated the use of FaSSIF as biorelevant apical substitute medium for FaHIF in the Caco-2 cell assay and the Ussing chambers setup. 33 To verify whether FaSSIF can be considered as a valuable substitute for FaHIF in the AMIsystem, both human and simulated intestinal media were explored as donor solvent system.…”

“…40 In this study, FaSSIF-v1 was used as donor medium because of (i) its simplicity and (ii) the strong correlation observed with FaHIF using other permeation tools (Caco-2 system and Ussing chambers model). 37,38 Nevertheless, it may be worthwhile to explore the passive permeability using FaSSIF-v2 and FaSSIF-v3 as donor medium in the AMI-system. 41…”

Caco-2 Cell Conditions Enabling Studies of Drug Absorption from Digestible Lipid-Based Formulations

“…P app and TEER measurements have been used extensively to evaluate monolayer integrity of Caco-2 cells ( 11 , 12 , 19 , 20 ). These parameters correlated well in this study (i.e.…”

“…This strategy has been used previously by Wuyts et al . who applied a barrier of mucin onto Caco-2 cells to protect them against fasted state human intestinal fluids ( 20 ). The concentration they used in their study was insufficient to completely protect the cells against some of the damaging effects, and so a larger amount of mucin was applied in this study (200 μL of 150 mg/mL mucin).…”