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Models and Methods to Evaluate Transport of Drug Delivery Systems Across Cellular Barriers
Published on: October 17, 2013
In Vitro Drug Absorption Models. II. Salicylate, Cefoxitin, α-Methyldopa and Theophylline Uptake in Cells and Rings:
P A Porter1, I Osiecka, R T Borchardt
1Merck Sharp and Dohme Research Laboratories, INTERx Research Corporation, 2201 W. 21st, Lawrence, Kansas, 66046.
Everted intestinal rings proved superior to isolated mucosal cells as an in vitro model for predicting intestinal drug absorption. This model showed better correlation with in vivo bioavailability for drugs like theophylline and salicylate.
Area of Science:
- Pharmacology
- Drug Delivery
- Biomedical Engineering
Background:
- In vitro models are crucial for predicting intestinal drug absorption.
- Evaluating the suitability of isolated mucosal cells and everted intestinal rings is essential for optimizing drug development.
Purpose of the Study:
- To compare the efficacy of isolated mucosal cells and everted intestinal rings as in vitro models for intestinal drug absorption.
- To assess the correlation between in vitro drug uptake and in vivo bioavailability.
Main Methods:
- Characterization of salicylate, cefoxitin, α-methyldopa, and theophylline uptake in isolated cells and everted intestinal rings.
- Analysis of time, concentration, and temperature dependence of drug absorption.
- Comparison of in vitro results with existing in vivo drug absorption data.
Main Results:
- Theophylline showed good absorption in all systems, with passive transport indicated.
- Salicylate, cefoxitin, and α-methyldopa exhibited time- and concentration-dependent absorption.
- Everted intestinal rings demonstrated a better correlation with in vivo drug bioavailability compared to isolated cells.
Conclusions:
- Everted intestinal rings are the preferred in vitro model for intestinal drug absorption studies due to technical feasibility, reproducibility, and superior correlation with in vivo data.
- Isolated mucosal cells showed greater variability and did not fully mimic in vivo absorption.
- Theophylline's absorption suggests a passive transport mechanism, while other drugs displayed more complex kinetics.
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