Comparison of the lipid composition of porcine buccal and esophageal permeability barriers

Pig esophageal mucosa has been shown to be a useful and practical substitute for buccal mucosa in in vitro permeability studies in that it offers a Larger surface area and it is much easier to prepare. Further, the tissues demonstrate similar histological. characteristics. The objectives of this work were to characterize the lipid composition of the esophageal. mucosa, to compare it to that of the buccal. tissue, and to correlate lipid composition with the membranes' permeabitity to fentanyl. The major lipid classes of buccal. and esophageal. epithelia were separated and analysed by automated multiple development high-performance thin-layer chromatography (AMD-HPTLC). The two epithelia presented a very similar lipid pattern. In general, there were more polar lipids than non-polar; glycosylceramides were relatively abundant whereas the amount of ceramides present was very small. The flux of fentanyl. applied as the citrate in aqueous solution was comparable across the buccal. and esophageal. barriers. Lipid extraction provoked a significant increase in permeability. In conclusion, this research confirms the suitability of the esophageal. mucosa as a model for buccal. permeability studies. (c) 2005 Elsevier Ltd. All rights reserved.