Related Experiment Video
Updated: Jul 30, 2026

Models and Methods to Evaluate Transport of Drug Delivery Systems Across Cellular Barriers
Published on: October 17, 2013
Intestinal absorption characteristics of the low solubility thiocarboxanilide UC-781
S Deferme1, J Van Gelder, F Ingels
1Laboratory of Pharmacotechnology and Biopharmacy, Katholieke Universiteit Leuven, O&N, Gasthuisberg, 3000 Leuven, Belgium.
Abstract:
The aim of this study was to determine the intestinal absorption characteristics of the antiviral agent UC-781 and to optimize the experimental conditions of the in vitro system for low solubility compounds. The absorption potential of UC-781 was studied with the Caco-2 system and with the rat intestinal perfusion technique. The low solubility of UC-781 required the use of solubility/dissolution rate enhancing agents (e.g. VitE-TPGS, Gelucire 44/14). The creation of sink conditions in the receiver compartment of the Caco-2 system was a prerequisite to reliably study the transport of this poorly soluble compound. After inclusion of VitE-TPGS in the acceptor solution, UC-781 could be characterized as a class II drug of the Biopharmaceutical Classification System (low solubility, high permeation across membranes). A significant concentration-dependent decrease in transport of UC-781 was observed upon increasing the concentration of VitE-TPGS in the apical compartment. This observation contrasts to the absorption enhancing properties of VitE-TPGS, and can probably be attributed to a decrease in the concentration of free UC-781 when using higher concentrations of the solubility/dissolution rate enhancing agents. The use of Gelucire 44/14 as a solubilizing agent resulted in a batch-dependent degradation of UC-781. The inclusion of the solubility/dissolution rate-enhancing agent VitE-TPGS did not result in absorption enhancement in the intestinal perfusion technique.
Related Concept Videos
Drug Absorption: Factors Affecting GI Absorption
In...
Factors Influencing Drug Absorption: Anatomical Parameters
Factors Influencing Drug Absorption: Physicochemical Parameters
Enhanced drug absorption can be achieved by reducing particle sizes and increasing surface areas, thereby facilitating...
Factors Influencing Drug Absorption: Drug Dissolution
Factors Affecting Dissolution: Drug Permeability, Stability and Stereochemistry
Hepatic Drug Clearance: Role of Transporters

