Influences of NaCl and Na2SO4 on the Micellization Behavior of the Mixture of Cetylpyridinium Chloride + Polyvinyl Pyrrolidone at Several Temperatures.

Herein, the conductivity measurement technique is used to determine the interactions that may occur between polyvinyl pyrrolidone (PVP) polymer and cetylpyridinium chloride (CPC) surfactant in the presence of NaCl and Na2SO4 of fixed concentration at variable temperatures (298.15-323.15 K) with an interval of 5 K. In the absence or presence of salts, we observed three critical micelle concentrations (CMC) for the CPC + PVP mixture. In all situations, CMC1 values of CPC + PVP system were found to be higher in water than in attendance of salts (NaCl and Na2SO4). Temperature and additives have the tendency to affect counterion binding values. Various physico-chemical parameters were analyzed and demonstrated smoothly, including free energy (ΔG0m), enthalpy (ΔH0m) and entropy change (ΔS0m). The micellization process is achieved to be spontaneous based on the obtained negative ΔG0m values. The linearity of the ΔHmo and ΔSmo values is excellent. The intrinsic enthalpy gain (ΔH0*m) and compensation temperature (Tc) were calculated and discussed with logical points. Interactions of polymer hydrophobic chains or the polymer + surfactant associated with amphiphilic surface-active drugs can employ a strong impact on the behavior of the gels.

Investigation of micellar and interfacial phenomenon of amitriptyline hydrochloride with cationic ester-bonded gemini surfactant mixture in different solvent media.

Herein, the interaction among the antidepressant drug amitriptyline hydrochloride (AMT) and a green gemini surfactant, ethane-1, 2-diyl bis(N,N-dimethyl-N-tetradecylammoniumacetoxy) dichloride (14-E2-14), via numerous techniques such as tensiometry, fluorimetry, FT-IR and UV-visible spectroscopy in three different media (aqueous 0.050 mol·kg-1 NaCl, 0.50 and 1.0 mol·kg-1 urea) were investigated. AMT is used to treat mental illness or mood problems, such as depression. The aggregation of biologically active ingredients can enhance the bioavailability of hydrophobic drugs. A significant interaction between AMT and 14-E2-14 was detected by tensiometric study as the critical micelle concentration (cmc) of AMT+14-E2-14 is reduced upon an increase of mole fraction (α1) of 14-E2-14. The decrease in cmc indicates the nonideality of studied mixtures of different compositions. Although, employed drug AMT is freely soluble in the aqueous and non-aqueous system but is not hydrophobic enough to act as its carrier. Instead, gemini surfactant formed spherical micelles in an aqueous system and their high solubilization capability, as well as their relatively lower cmc value, makes them highly stable in vivo. The cmc values of AMT+14-E-14 mixtures in all cases were further decreased and increased in NaCl and urea solutions respectively as compared with the aqueous system. Numerous micellar, interfacial, and thermodynamic parameters have been measured by applying various theoretical models. The obtained changes in the physicochemical assets of AMT upon adding of 14-E2-14 are likely to enhance the industrial and pharmaceutical applications of gemini surfactants. The negative interaction parameters (ßm and ßσ), indicate synergistic attraction is occurring in the mixed systems. The aggregation number (Nagg), Stern-Volmer constant (Ksv), etc. are attained through the fluorescence method, also supporting the attractive interaction behavior of AMT+14-E2-14 mixtures in all solvents. The Nagg was found to increase in the salt solution and decrease in the urea system compared with the aqueous solution. FT-IR and UV-visible analysis also depict the interaction between the constituent alike tensiometry and fluorimetry methods. The results suggested that gemini surfactants may serve as a capable drug delivery agent for antidepressants, improving their bioavailability.

Aggregation and interfacial phenomenon of amphiphilic drug under the influence of pharmaceutical excipients (green/biocompatible gemini surfactant).

In the current study, we have examined the interaction amongst an antidepressant drug amitriptyline hydrochloride (AMH) and ethane-1, 2-diyl bis(N,N-dimethyl-N-cetylammoniumacetoxy) dichloride (16-E2-16, a green gemini surfactant) through tensiometric and fluorimetric techniques in aqueous/electrolyte/urea solutions. Significant variations are observed in the various evaluated parameters in the present study. Gemini 16-E2-16 has outstanding surface properties along with a much lower cmc value, demonstrating very little toxicity as well as considerable antimicrobial activity. The cmc values of mixtures decrease through increase in mole fraction (α1) of 16-E2-16, which specifies the nonideality of the solution mixtures, along with demonstrating the occurrence of mixed micellization too. Negative ßRub values signify on the whole attractive force of interaction between constituents of mixed micelles. Owing to the incidence of electrolyte NaCl (50 mmol.kg-1), lowering of the micelles' surface charge happens, resulting in aggregation taking place at lower concentration while the presence of urea (NH2CONH2) halts micellization taking place, which means the cmc value increases in the attendance of urea. The [Formula: see text] values for all systems were negative along with the presence of electrolyte/urea. The excess free energy (Gex) of studied mixed systems was also estimated and found to be negative for all the systems. Using the fluorescence quenching method, the micelle aggregation number (Nagg) was evaluated and it was found that the contribution of gemini surfactant was always more than that of the AMH and their value enhances in the existence of electrolyte while decreasing in the attendance of NH2CONH2 in the system. In addition, other fluorescence parameters such as micropolarity (I1/I3), dielectric constant (Dexp) as well as Stern-Volmer binding constants (Ksv) of mixed systems were evaluated and the results showed the synergistic performance of the AMH + 16-E2-16 mixtures. Along with tensiometric and fluorimetric techniques, FT-IR spectroscopy was also engaged to reveal the interaction among constituents.