Studies of Mixed Micellization Behavior of Promethazine Hydrochloride and Triton X-100 in the Presence of Additives Using Multiple Techniques

In the present study, we have examined the mixed micellization behavior of promethazine hydrochloride (PMT) and the nonionic surfactant Triton X-100 mixtures at different mole fractions of TX-100 (α1) in aqueous solutions with and without additives (CTAB, glycine, vitamin-C and PVP) using conductometric, tensiometric and fluorescence techniques. PMT belongs to a class of amphiphilic drugs called phenothiazines and is used as an antihistamine, analgesic and sedative. Various parameters which include the ideal critical micelle concentration (cmcid), ideal micellar mole fraction, X1id\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$X_{1}^{\text{id}}$$\end{document}, of TX-100, micellar composition, X1mic\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$X_{1}^{\text{mic}}$$\end{document}, of TX-100, interaction parameter (β), activity coefficients (f1mic\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$f_{1}^{\text{mic}}$$\end{document} and f2mic\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$f_{2}^{\text{mic}}$$\end{document}), thermodynamic parameters ΔGmic0,ΔGad0andΔGmicE\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\left( {\Delta G_{\text{mic}}^{ 0} , \;\Delta G_{\text{ad}}^{0} \;{\text{and}}\;\Delta G_{\text{mic}}^{\text{E}} } \right)$$\end{document} and interfacial parameters (Γmax, Amin, and Πcmc) have been calculated by using Clint’s and Rubingh’s models. In our study, we have found that the cmc < cmcid, β < 0 and f1mic\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$f_{1}^{\text{mic}}$$\end{document} and f2mic\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$f_{2}^{\text{mic}}$$\end{document} < 1; all the mixtures show synergism X1id\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$X_{1}^{\text{id}}$$\end{document} as well as non-ideality. The values of ΔGad0>ΔGmic0\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\Delta G_{\text{ad}}^{0} > \Delta G_{\text{mic}}^{ 0}$$\end{document} for all the systems indicate that adsorption phenomenon occurs primarily as compared to the micellization process. The negative values of ΔGmicE\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\Delta G_{\text{mic}}^{\text{E}}$$\end{document} for all α1 in the absence and presence of additives indicate greater stability of the micelles of mixtures than for the micelles of pure components. The interfacial parameters give information about the packing of amphiphilic molecules.