Self-association of verapamil in aqueous electrolyte solution

The self-association of the amphiphilic. drug verapamil hydrochloride in wa ter and in the presence of added electrolyte (0.0-0.009 mol kg(-1) NaCl) ha s been studied by light-scattering and NMR techniques. Critical micelle con centrations were determined from inflections in the data from both techniqu es. Aggregation numbers determined by the application of mass action theory to the concentration dependence of H-1 NMR chemical shifts were in agreeme nt with values from static light scattering and indicated very limited asso ciation (aggregation numbers between 2 and 4). (C) 2001 Academic Press.