Micropolarity and Microviscosity of Amitriptyline and Dextran Sulfate/Carrageenan‐Amitriptyline Systems: The Nature of Polyelectrolyte–Drug Complexes

摘要: ABSTRACT The polarity and viscosity of the microenvironment aggregates cationic amphiphilic drug amitriptyline dextran sulfate (DxS)/carrageenan‐amitriptyline in aqueous solution were investigated by means steady state time‐resolved fluorescence. For latter systems, equilibrium dialysis capillary viscometry also used. micropolarity as detected pyrene indicated formation aggregates, both with without polyelectrolyte, having properties similar to “traditional” micelles. lifetime amitriptyline‐ amitriptyline‐polyelectrolyte was long (≈230 ≈300 ns, respectively), indicating that well protected from oxygen quenching, especially so case. microviscosity themselves, presence high, intramolecular excimer 1,3‐di(1‐pyrenyl)‐propane (P3P), rotational diffusion fluorescence depolarization 1,6‐diphenyl‐1,3,5‐hexatriene (DPH), relaxation about bonds [p‐(dimethylamino)benzylidene]‐malonitrile (BMN). These results concurrent decrease bulk indicate acting polycounterion, is tightly wrapped around aggregates. Amitriptyline hence behaves accordance accepted models surfactant‐polyelectrolyte interaction. © 2001 Wiley‐Liss, Inc. American Pharmaceutical Association J Pharm Sci 90:1665–1677,