Solution properties of phenothiazine drug promazine hydrochloride with cationic hydrotropes in aqueous/electrolyte solution at different temperature

• Published in: Journal of physical organic chemistry Vol. 29; no. 9; pp. 476 - 489
• Main Authors: Rub, Malik Abdul, Azum, Naved, Asiri, Abdullah M., Zayed, Mohie E. M., Al-Youbi, Abdulrahman O.
• Format: Journal Article
• Language: English
• Published: Bognor Regis Blackwell Publishing Ltd 01.09.2016; Wiley Subscription Services, Inc
• Subjects: critical micelle concentration (cmc); enthalpy; mixed micelles; promazine hydrochloride (PMZ); stability
• ISSN: 0894-3230; 1099-1395
• DOI: 10.1002/poc.3570

The current work deals with the mixed micellization phenomena of surface active promazine hydrochloride (PMZ) drug with cationic hydrotropes (para‐toluidine hydrochloride and ortho‐toluidine hydrochloride) in absence and occurrence of 50 mmol kg−1 NaCl at five different temperature (293.15–313.15 K). PMZ is an amphiphilic phenothiazine drug and employed for the cure of mania and schizophrenia. Conductometry measurement was employed to gain a detailed picture of the interactions between drug and hydrotrope molecules. The experimental data were analyzed according to different mixing models within the outline of the pseudophase separation model. The evaluated values of critical micelle concentration (cmc) were found to be inferior than cmcid values signifying attractive interactions involving the both components in the solutions. NaCl further reduces the cmc of pure amphiphiles and their mixed systems as a result of screening of the electrostatic repulsion between the polar head groups. The micellar mole fractions (X1) of hydrotropes evaluated by various proposed models were constantly more than ideal values ( X1id) signifying high involvements of hydrotrope in mixed micelles. Activity coefficients ( f1Rub and f2Rub) were always below one in all cases signifying synergism in mixed micelles. Thermodynamic parameters favor the process of micellization which is found to be entropy driven. The negative values of free energies of mixing demonstrated the stability of the mixed systems of drug and hydrotrope. Copyright © 2016 John Wiley & Sons, Ltd. The current work deals with the mixed micellization phenomena of promazine hydrochloride (PMZ) drug with cationic hydrotropes in absence/presence of 50 mmol kg−1 NaCl at different temperature. PMZ is an amphiphilic phenothiazine drug and employed for the cure of mania and schizophrenia. The experimental data were analyzed according to different mixing models. NaCl further reduces the critical micelle concentration of pure amphiphiles and their mixed systems. Thermodynamic parameters favor the process of micellization, which is found to be entropy driven.