Enhancement of paracellular drug transport across epithelia —in vitro andin vivo studies

Conclusion

In conclusion the use of anin vitro cell culture system proved to be very valuable for (partly) elucidating the way of action of absorption-enhancing compounds and for the investigation of critical factors associated with absorption enhancement. The use of isolated cell culture systems like the Caco-2 cells can also have some drawbacks. Although this cell line is considered to be a very adequate model for intestinal epithelium, its properties might in some respects not be the same as those of normal cells, due to the fact that the cell line, originating from a carcinoma, consists of transformed cells. Direct extrapolation of potentially useful methods from thein vitro to thein vivo situation remains an important issue to consider as well and has been shown to be hazardous in the current investigations. A principal reason for this may be associated with the problem of maintaining conditionsin vivo very similar to those investigatedin vitro.