Mixtures of mucin and oppositely charged surfactant aggregates with varying charge density. Phase behavior, association, and dynamics

Summary, in English

The nonionic surfactant Tween80 is a commonly used excipient in drug formulations containing an active substance with low aqueous solubility. Model drug vehicles with varying charge density were obtained by mixing Tween80 (PS-80) with the cationic surfactant Tetradecyltrimethylammonium chloride (TTAC), thus forming mixed micelles. The micelles were mixed with the negatively charged polyelectrolyte mucin, which is a component in the protective mucus layer covering epithelial cell linings. Depending on the composition of the mixture, complex-formation could be followed by precipitation. Using X-ray diffraction, it was found that the precipitate contained a lamellar phase with properties sensitive to the proportion of PS-80. Higher amounts of PS-80 were found to oppose phase separation. Further analysis in the one-phase region, or alternatively of the supernatant of two-phase samples, by H-1 NMR, HPLC, and diffusion measurements with PGSE-NMR led to the conclusions that at low proportion of PS-80 aggregates composed of mixed (PS-80 and TTAC) micelles and mucin were formed, whereas increased concentrations of PS-80 favored the dissolution of the precipitate and limited the interactions between mixed micelles and the polymer.

• Author: Géraldine Lafitte; Krister Thuresson; Olle Söderman
• Department/s: Physical Chemistry
• Publishing year: 2005
• Language: English
• Pages: 7097-7104
• Publication/Series: Langmuir
• Volume: 21
• Issue: 16
• Links: http://dx.doi.org/10.1021/la0472807
• Document type: Journal article
• Publisher: The American Chemical Society (ACS)
• Topic: Physical Chemistry
• Status: Published
• ISBN/ISSN/Other: ISSN: 0743-7463