title: Polyelectrolyte/amphiphile interaction studied by surface tension measurements.
abstract: The interaction of kappa-carrageenan with three positively charged drug molecules with amphiphile character has been examined using surface tension measurements. The surface tension was measured by the pendant drop method which makes possible the determination at an apparent steady state which is important for polymeric systems. The results are compared with adsorption isotherms from dialysis equilibrium. The surface tension data, show that the presence of kappa-carrageenan in the amphiphile solutions leads to an increased and pronounced lowering of the surface tension in a low concentration range of amphiphile. It is also shown that not only the hydrophobicity of the amphiphile but also the structure of the polyelectrolyte (charge density and helix-coil structure) largely determine the extent of interaction.
authors.affiliation: Physical Pharmaceutical Chemistry, Uppsala University, Sweden.
authors.forename: B
authors.initials: B
authors.lastname: Persson
authors.forename: N
authors.initials: N
authors.lastname: Caram-Lelham
authors.forename: L O
authors.initials: LO
authors.lastname: Sundelöf
mesh_terms: D000327:Adsorption; D000639:Amitriptyline / Q000737:chemistry*; D002351:Carrageenan / Q000737:chemistry*; D002997:Clomipramine / Q000737:chemistry*; D004316:Doxepin / Q000737:chemistry*; D004573:Electrolytes / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D009994:Osmolar Concentration; D012492:Salts; D013329:Structure-Activity Relationship; D013500:Surface Tension; D013997:Time Factors
chemical_list: D004573:Electrolytes; D012492:Salts; D004316:Doxepin; D000639:Amitriptyline; D002351:Carrageenan; D002997:Clomipramine