Interaction of amphiphilic drug amitriptyline hydrochloride with β-cyclodextrin as studied by conductometry, surface tensiometry and viscometry

► β-Cyclodextrin increases the critical micelle concentration of amitriptyline hydrochloride. ► Free energy of micellization suggests that the micellization becomes less favorable in presence of β-cyclodextrin. ► It was revealed from surface tension measurements that the complex was not surface active.