Clouding phenomenon of amphiphilic drug promazine hydrochloride solutions: Influence of pharmaceutical excipients

Various additives viz. hydrotropes, bile salts, fatty acid and cyclodextrin effect on the cloud point (CP) behavior of amphiphilic drug promazine hydrochloride (PMZ) in 1 mmol dm(-3) 14-4-14 + 10 mmol dm(-3) sodium phosphate (SP) buffer solutions have been investigated in the present study. These various additives are usually used as pharmaceutical excipients. The additives like anionic hydrotropes, bile salts and fatty acid salts increase the CP of PMZ, when added in low concentrations, whereas at high concentration, decrease it. Cationic and nonionic hydrotropes increase the CP of PMZ solutions at all concentration. Cyclodextrin behave like simple sugar is found to decrease the CP of the drug solutions at all concentrations. Gemini surfactant (14-4-14) has been found a better surfactant that can prevent clouding under physiological condition. It can thus be used as a drug-carrier system that increases the storage stability. The thermodynamic parameters are also evaluated: where Delta G(c)(o) is found to be negative and Delta H-c(o) and T Delta S-c(o) values are negative as well as positive depending upon type and nature of additive. (C) 2014 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.