Cloud point variation of amphiphilic drug promethazine hydrochloride with added surfactants

► Computer simulations have indicated that drugs partition and accumulate heterogeneously in the membrane. ► Their local concentrations may be much higher than in the bulk aqueous phase or even in the other regions in the lipid bilayer. ► The value of the Cloud Point (CP) depends on the structure of the amphiphile, the presence of additives, and the concentration of the amphiphile. ► It is, therefore, essential to have knowledge of clouding behavior of amphiphilic drugs under varying conditions.