Studies on the Interactions Between Mucin and Surfactant Aggregates Containing the Cationic Surfactant Dodecyl Betainate

The interactions of surfactant aggregates containing the cationic, cleavable surfactant dodecyl betainate (DB) with mucin are investigated. The aggregates were either mixed micelles of DB and the nonionic surfactant PS-80 in different ratios or a dispersion of the commercial self-emulsifying drug-delivery formulation Sandimmun Neoral charged with DB. It is found that for the surfactant aggregates to show any notable interactions with mucin these must have a high positive charge density. Also presented are results from Ussing chamber experiments, which suggest that DB has a limited impact on the integrity and the barrier function of the intestinal epithelium.