Solution and surface properties of amphiphilic drug - nonelectrolyte systems

摘要

The surface tension values of amphiphilic drugs amitriptyline hydrochloride (AMT, an antidepressant) and promethazine hydrochloride (PMT, a phenothiazine) solutions in the presence of different fixed concentrations of alcohols (ethanol to octanol) and sugars were measured by the ring detachment method. The results indicated that long-chain alcohols form mixed micelles with both the drugs (as critical micelle concentration, cmc, decreases in their presence). Short-chain alcohols remain in aqueous phase and almost constant cmc values were obtained. Sugars, by increasing the hydrophobic interactions, decrease the drug cmcs. Maximum surface excess concentration at the air/solution interface (Γ _(max)) decreases for long-chain alcohols and sugars, but remains constant for short-chain alcohols. The minimum area per drug molecule (A _(min)) follows the opposite trend.