No abstract

No abstract

No abstract

Micellization (aggregation) phenomenon of amphiphilic phenothiazine drug promazine hydrochloride (PMZ) and sodium dodecylbenzenesulfonate (SDBS) mixtures in absence and attendance of 50 mmol•kg À1 NaCl (salt)/300 mmol•kg À1 urea was investigated conductometrically at five various temperatures (293.15-318.15 K) at gaps of T = 5 K. PMZ is employed for the cure of mania and schizophrenia. The critical micelle concentration (CMC) values have been evaluated and defined in terms of hydrophobicity and hydrophilicity of PMZ and SDBS in aqueous and nonaqueous solutions. With increasing the temperature, the CMC first increases then decreases. At 303.15 K, the maximum CMC values were obtained in absence and presence of NaCl/urea. NaCl reduces the CMC of pure amphiphiles and their mixtures while urea increases. Various physicochemical parameters such as CMC id (ideal critical micelle concentration), micellar mole fraction of SDBS (X 1 ) (calculated by different proposed models), and interaction parameter have been evaluated and discussed in detail. The values of degree of dissociation (g) and CMC of the micelles were utilized to evaluate the different thermodynamic parameters. Activity coefficients (f 1 and f 2 ) and excess free energy of micellization (ΔG ex ) values were also evaluated. All outcomes obtained herein show attractive interactions in the mixtures of PMZ and SDBS.

No abstract

aIn the present paper, reaction of zinc-glycylphenylalanine ([Zn(II)-Gly-Phe] + ) with ninhydrin has been investigated in gemini (m-s-m type; m = 16, s = 4-6) surfactants at temperature (70°C) and pH (5.0). Monitoring the appearance of product at 400 nm was used to follow the kinetics, spectrophotometrically. The order of the reaction with respect to [Zn(II)-Gly-Phe] + was unity while with respect to [ninhydrin] was fractional. The reaction constants involved in the mechanism were obtained. In addition to the rate constant (k Ψ ) increase and leveling-off regions are observed with the geminis, just like as seen with conventional surfactant hexadecyltrimethylammonium bromide (CTAB), the former produced a third region of increasing k Ψ at higher concentrations. A close agreement between observed and calculated rate constants was found under varying experimental conditions. A suitable mechanism consistent with the experimental findings has been proposed.

Herein, we have studied the interaction between cationic surfactant (conventional [myristyltrimethylammonium bromide, MTAB] as well as gemini surfactant 1, 4-butanediyl-α, ω-bis(dimethyltetradecylammonium bromide) (14-4-14)) and antiinflammatory sodium salt of ibuprofen (IBU) drug in aqueous solutions by using tensiometry method at 298.15 K. The means of the interaction of drugs by added foreign materials is of paramount importance in the drug delivery. Ibuprofen is used for the relief of pain, fever, and swelling. From this study we have evaluated different parameters, for example, critical micelle concentration (cmc), micellar mole frac-

A conductivity method was used to see effects of a ciprofloxacin hydrochloride (CFH)/CFH + polyols (organic compounds with multiple hydroxyl groups (glucose and fructose)) on aggregation phenomenon of sodium dodecyl sulfate (SDS) at 298.15–318.15 K.