MIXED MICELLES OF STRUCTURALLY RELATED ANTIDEPRESSANT DRUGS

The composition of micelles in a binary mixture of the amphiphilic ant idepressant drugs imipramine hydrochloride and clomipramine hydrochlor ide has been determined from an analysis of the variation of the criti cal micelle concentration from conductivity techniques as a function o f solution composition. The equilibrium distribution of components bet ween micelle and monomer phases was evaluated using a theoretical trea tment based on excess thermodynamic quantities. The nonideality of mix ing, expressed in terms of the interaction parameter a, was appreciabl e in systems containing low imipramine mole fractions, suggesting diff erences in the packing characteristics within micelles of these two dr ugs.