Thermodynamics of the solubility of reserpine in {{2-(2-ethoxyethoxy)ethanol + water}} mixed solvent systems at different temperatures

Thermodynamics of solubility of the bioactive compound reserpine in various {2-(2-ethoxyethoxy)ethanol + water} mixed solvent systems was investigated in this study. The solubility of reserpine was determined from T = (298.15 to 338.15) K at atmospheric pressure using the reported method of Higuchi and Connors. Values of the measured solubility of reserpine were correlated with the ideal and Yalkowsky models. The root mean square deviations (RMSD) were observed to be less than 0.020 by an ideal model. However, the RMSD values were observed as less than 0.050 by the Yalkowsky model. The mole fraction solubility of reserpine was observed highest in pure 2-(2-ethoxyethoxy)ethanol (7.69 · 10⁻⁴ at T = 298.15 K) and lowest in pure water (9.71 · 10⁻⁷ at T = 298.15 K) at each temperature investigated. The results of the Van’t Hoff and Krug analysis (thermodynamic studies) indicated endothermic and spontaneous dissolution of reserpine in all {2-(2-ethoxyethoxy)ethanol + water} mixed solvent systems.     

Equilibrium solubility of sodium 2-naphthalenesulfonate in binary (sodium chloride + water), (sodium sulfate + water), and (ethanol + water) solvent mixtures at temperatures from (278.15 to 323.15) K

The equilibrium solubility of sodium 2-naphthalenesulfonate in binary (sodium chloride + water), (sodium sulfate + water), and (ethanol + water) solvent mixtures was measured at elevated temperatures from (278.15 to 323.15) K using a steady-state method. With increasing temperatures, the solubility increases in aqueous solvent mixtures. The results of these results were regressed by a modified Apelblat equation. The dissolution entropy and enthalpy determined using the method of the least-squares and the change of Gibbs free energy calculated with the values of Δ_diffS^o and Δ_diffH^o at T = 278.15 K.     

Thermodynamic models for determination of the solubility of dibenzothiophene in (methanol + acetonitrile) binary solvent mixtures

In this paper, we focused on solubility and solution thermodynamics of dibenzothiophene. By the gravimetric method, the solubility of dibenzothiophene was measured in (methanol + acetonitrile) binary solvent mixtures at temperatures from (278.15 to 333.15) K under atmosphere pressure. The solubility data were fitted using a modified Apelblat equation, a variant of the combined nearly ideal binary solvent/Redich–Kister (CNIBS/R–K) model and Jouyban–Acree model. Computational results showed that the modified Apelblat equation was superior to the other two equations. In addition, the thermodynamic properties of the solution process, including the Gibbs free energy, enthalpy, and entropy, were calculated by the van’t Hoff analysis. The experimental results showed that methanol could be used as effective anti-solvents in the crystallization process.     

Solubility of celecoxib in carbitol + water mixtures at various temperatures: experimental data and mathematical modelling

ABSTRACT

A brief review on various solubilisation techniques of coxibs is provided and the solubility of celecoxib (CXB) in binary solvent mixtures of {carbitol (1) + water (2)} is reported at temperatures ranging from 298.2 to 313.2 K. Three cosolvency models, i.e. Yalkowsky model, Jouyban–Acree model and the Jouyban–Acree–van’t Hoff model, have been used for correlating the reported data, and the mean relative deviations are employed to evaluate the accuracy of the fitness. Solubilities are also predicted by the generally trained version of the Jouyban–Acree model and its combined model with Abraham solute parameters previously proposed for {carbitol (1) + water (2)} binary mixtures. Furthermore, the apparent thermodynamic properties of dissolution process of CXB in all -investigated solvents were calculated according to van’t Hoff and Gibbs equations.     

Equilibrium solubility of sodium 3-sulfobenzoate in binary (sodium chloride + water), (sodium sulfate + water), and (ethanol + water) solvent mixtures at temperatures from (278.15 to 323.15) K

The solubility of sodium 3-sulfobenzoate in binary (sodium chloride + water), (sodium sulfate + water), and (ethanol + water) solvent mixtures was measured at elevated temperatures from (278.15 to 323.15) K by a steady-state method. The results of these experiments were correlated by a modified Apelblat equation. The dissolution enthalpy and entropy of sodium 3-sulfobenzoate in aqueous solutions of different mole fraction were obtained.     

Solubility of sildenafil citrate in propylene glycol + water mixtures at various temperatures

The solubility of sildenafil citrate (SC) in aqueous mixtures of propylene glycol (PG) was investigated. This study was carried out at different mass fractions of PG ranging from 0.1 to 0.9 at T = 293.2–313.2 K. The solubility of SC in the mixed solutions increased with increasing temperature and PG mass fraction.

The solubility values were correlated by two co-solvency models (Jouyban–Acree model and van’t Hoff–Jouyban–Acree model). The mean relative deviations (MRD) were 5.7% and 5.5%, respectively. Density of the SC-saturated solutions over the entire solvent composition and temperature range was also measured and the results correlated with the Jouyban–Acree model. Furthermore, the apparent thermodynamic properties, dissolution enthalpy, dissolution entropy and Gibbs free energy change of dissolution process of SC in all the mixed solvents were calculated according to van’t Hoff and Gibbs equations. Dissolution of SC in these mixed solvents is an endothermic process.     

Solubility prediction of deferiprone in N-methyl-2-pyrrolidone + ethanol mixtures at various temperatures using a minimum number of experimental data

Experimental solubility of deferiprone (DFP) in N-methyl-2-pyrrolidone (NMP) + ethanol (EtOH) mixtures at 293.2, 298.2, 303.2 and 308.2 K was determined and mathematically represented using various models. The trained versions of the van’t Hoff equation, its combined version with log-linear model, Jouyban–Acree model and a combination of van’t Hoff + Jouyban–Acree model were reported to simulate DFP solubility in the binary mixture compositions at various temperatures. The mean percentage deviation (MPD) was used as an accuracy criterion. The obtained overall MPDs for back-calculated and predicted solubility of DFP in NMP + EtOH mixtures varied from 1.1% to 3.2% and 2.6% to 6.6%, respectively. Some of apparent thermodynamic quantities for the dissolution processes of DFP are also reported.     

Solubility and solution thermodynamics of 2,3,4,5-tetrabromothiophene in (ethanol + tetrahydrofuran) binary solvent mixtures

The solubility of 2,3,4,5-tetrabromothiophene in (ethanol + tetrahydrofuran) binary solvent mixtures was measured within the temperature range from (278.15 to 322.15) K. The solubility increases with the rise of temperature, while it decreases with increasing ethanol content at constant temperature. The experimental data were fitted using the two variants of the combined nearly ideal binary solvent/Redlich–Kister (CNIBS/R–K) equation and the Jouyban–Acree equation, respectively. All the three equations were proven to give good representations of the experimental values. Computational results showed that the variant two of CNIBS/R–K equation was superior to the other two equations. The thermodynamic properties of the solution process, including the Gibbs free energy, enthalpy, and entropy, were calculated by the van’t Hoff analysis. The values of both the enthalpy change and the standard molar Gibbs free energy change of solution were positive, which indicated that the process was endothermic.     

Solubility of gallic acid in liquid mixtures of (ethanol + water) from (293.15 to 318.15) K

The solubility of gallic acid in (water + ethanol) binary solvents was determined from (293.15 to 318.15) K at atmospheric pressure using a thermostatted reactor and UV/vis spectrophotometer analysis. The effects of binary solvents composition and temperature on the solubility were discussed. It was found that gallic acid solubility in (water + ethanol) mixed solvents presents a maximum-solubility effect. Two empirical equations were proposed to correlate the solubility data. The calculated solubilities show good agreement with the experimental data within the studied temperature range. Using the experimentally measured solubilities, the thermodynamic properties of dissolution of the gallic acid such as Gibbs energy (Δ_solG°), molar enthalpy of dissolution (Δ_solH°), and molar entropy of dissolution (Δ_solS°) were calculated.     

The solubility of bosentan in aqueous-2-propanol mixtures at several temperatures,measurement and data correlation

ABSTRACT

The solubilities of bosentan (BST) in binary aqueous mixtures of 2-propanol at temperatures ranging from 293.15 to 313.15 K were determined using a shake-flask method. The produced data were modelled with the Jouyban-Acree-van’t Hoff model and difference between the predicted data and experimental ones were illustrated by percent average relative deviations (%ARD). Moreover, the thermodynamic functions of dissolution for BST in the aqueous 2-propanol solutions were computed which suggest that the dissolution process is endothermic and not spontaneous.     

(Liquid + liquid) equilibria for ternary mixtures of (polyvinylpyrrolidone + MgSO4 + water) at different temperatures

Experimental (liquid + liquid) equilibrium (LLE) data were determined for a ternary system (polyvinylpyrrolidone + MgSO₄ + water) at various temperatures of (298.15, 303.15, and 308.15) K. The UNIQAC, modified regular solution, modified Wilson and Chen-NRTL models were used to correlate the experimental tie-line data. The results show that at each temperature, the quality of fitting is better with the Chen-NRTL model.     

Excess molar properties of ternary system (ethanol + water + 1,3-dimethylimidazolium methylsulphate) and its binary mixtures at several temperatures

The density, dynamic viscosity, and refractive index of the ternary system (ethanol + water + 1,3-dimethylimidazolium methylsulphate) at T = 298.15 K and of its binary systems 1,3-dimethylimidazolium methylsulphate with ethanol and with water at several temperatures T = (298.15, 313.15, and 328.15) K and at 0.1 MPa have been measured over the whole composition range. From these physical properties, excess molar volumes, viscosity deviations, refractive index deviations, and excess free energy of activation for the binary systems at the above mentioned temperatures, were calculated and fitted to the Redlich–Kister equation to determine the fitting parameters and the root-mean-square deviations. For the ternary system, the excess properties were calculated and fitted to Cibulka, Singh et al., and Nagata and Sakura equations. The ternary excess properties were predicted from binary contributions using geometrical solution models.     

Solubility of daidzin in different organic solvents and (ethyl alcohol + water) mixed solvents

The solubility of daidzin in different organic solvents and (ethyl alcohol + water) mixed solvents was measured by high performance liquid chromatography (HPLC) analysis method from T = (283.2 to 323.2) K at atmosphere pressure. The results show that at higher temperature more daidzin dissolves, and moreover, the solubility increases with the ethyl alcohol mole fraction increase in the (ethyl alcohol + water) mixed solvents. The experimental solubility values were correlated by a simplified thermodynamic equation, λh equation and modified Apelblat equation. Based on the solubility of daidzin, the enthalpy and entropy of solution were also evaluated by van’t Hoff equation. The results illustrated that the dissolution process of daidzin is endothermic and entropy driven.     

Physical properties of the ternary system (ethanol + water + 1-butyl-3-methylimidazolium methylsulphate) and its binary mixtures at several temperatures

In this paper, we report experimental densities, dynamic viscosities, and refractive indices and their derived properties of the ternary system (1-butyl-3-methylimidazolium methylsulphate + ethanol + water) at T = 298.15 K and of its binary systems 1-butyl-3-methylimidazolium methylsulphate with ethanol and with water at several temperatures T = (298.15, 313.15, 328.15) K. These physical properties have been measured over the whole composition range and at 0.1 MPa. Excess molar volumes, viscosity deviations, and excess free energy of activation for the binary systems at the abovementioned temperatures, were calculated and fitted to the Redlich–Kister equation to determine the fitting parameters and the root-mean-square deviations and for the ternary systems were calculated and fitted to Cibulka, Singh et al., and Nagata and Sakura equations. The ternary excess properties were predicted from binary contributions using geometrical solution models. Refractive indices were measured from T = 298.15 K over the whole composition range for the binary and ternary systems. The results were used to calculate deviations in the refractive index.     

(Vapor-liquid) equilibria and excess Gibbs free energy functions of (ethanol + glycerol), or (water + glycerol) binary mixtures at several temperatures

The vapor pressures of (ethanol + glycerol) and (water + glycerol) binary mixtures were measured by means of two static devices at temperatures between (273 and 353 (or 363)) K. The data were correlated with the Antoine equation. From these data, excess Gibbs free energy functions (G^E) were calculated for several constant temperatures and fitted to a fourth-order Redlich–Kister equation using the Barker method. The (ethanol + glycerol) binary system exhibits positive deviations in G^E where for the (water + glycerol) mixture, the G^E is negative for all temperatures investigated over the whole composition. Additionally, the NRTL, UNIQUAC and Modified UNIFAC (Do) models have been used for the correlation or prediction of the total pressure.     

Activity coefficients of CaCl2 in (maltose + water) and (lactose + water) mixtures at 298.15 K

Activity coefficients of CaCl₂ in disaccharide {(maltose, lactose) + water} mixtures at 298.15 K were determined by cell potentials. The molalities of CaCl₂ ranged from about 0.01 mol · kg^?1 to 0.20 mol · kg^?1, the mass fractions of maltose from 0.05 to 0.25, and those of lactose from 0.025 to 0.125. The cell potentials were analyzed by using the Debye–Hückel extended equation and the Pitzer equation. The activity coefficients obtained from the two theoretical models are in good agreement with each other. Gibbs free energy interaction parameters (g_ES) and salting constants (k_S) were also obtained. These were discussed in terms of the stereo-chemistry of saccharide molecules and the structural interaction model.     

Excess volumes of mixing in (N,N-dimethylacetamide + methanol + water) and (N,N-dimethylacetamide + ethanol + water) at the temperature 313.15 K

Precise excess volumes of mixing measurements at T = 313.15 K are reported over the whole composition range for binary mixtures: (N,N-dimethylacetamide + water), (N,N-dimethylacetamide + methanol), (N,N-dimethylacetamide + ethanol) and for the ternary mixtures (N,N-dimethylacetamide + methanol + water) and (N,N-dimethylacetamide + ethanol + water). For all the systems, large negative deviations from ideality are observed. The binary results have been fitted using the Redlich–Kister type polynomial. The possibility of predicting the ternary results from the binary ones was examined.     

Isopiestic measurement and solubility evaluation of the ternary system (CaCl2 + SrCl2 + H2O) at T = 298.15 K

Water activities in the ternary system (CaCl₂ + SrCl₂ + H₂O) and its sub-binary system (CaCl₂ + H₂O) at T = 298.15 K have been elaborately measured by an isopiestic method. The data of the measured water activity were used to justify the reliability of solubility isotherms reported in the literature by correlating them with a thermodynamic Pitzer–Simonson–Clegg (PSC) model. The model parameters for representing the thermodynamic properties of the (CaCl₂ + H₂O) system from (0 to 11) mol ⋅ kg⁻¹ at T = 298.15 K were determined, and the experimental water activity data in the ternary system were compared with those predicted by the parameters determined in the binary systems. Their agreement indicates that the PSC model parameters can reliably represent the properties of the ternary system. Under the assumption that the equilibrium solid phases are the pure solid phases (SrCl₂ ⋅ 6H₂O and CaCl₂ ⋅ 6H₂O)_(s) or the ideal solid solution consisting of CaCl₂ ⋅ 6H₂O_(s) and SrCl₂ ⋅ 6H₂O_(s), the solubility isotherms were predicted and compared with experimental data from the literature. It was found that the predicted solubility isotherm agrees with experimental data over the entire concentration range at T = 298.15 K under the second assumption described above; however, it does not under the first assumption. The modeling results reveal that the solid phase in equilibrium with the aqueous solution in the ternary system is an ideal solid solution consisting of SrCl₂ ⋅ 6H₂O_(s) and CaCl₂ ⋅ 6H₂O_(s). Based on the theoretical calculation, the possibility of the co-saturated points between SrCl₂ ⋅ 6H₂O_(s) and the solid solution (CaCl₂ ⋅ 6H₂O + SrCl₂ ⋅ 6H₂O)_(s) and between CaCl₂ ⋅ 6H₂O_(s) and the solid solution (CaCl₂ ⋅ 6H₂O + SrCl₂ ⋅ 6H₂O)_(s), which were reported by experimental researchers, has been discussed, and the Lippann diagram of this system has been presented.     

Solubility and solution thermodynamics of 2, 6-bis (4-hydroybenzylidene) cyclohexanone in pure and binary solvents at various temperatures

Solubility of 2, 6-bis (4-hydroxybenzylidene) cyclohexanone (BHBC) in pure solvents such as 1,4-dioxane, methanol, 1-butanol, 1-propanol, ethyl acetate, acetone, tetrahydrofuran (THF), glacial acetic acid, dimethyl sulphoxide (DMSO) and binary solvents dimethyl formamide (DMF) and (1-Propanol + Tetrahydrofuran) were investigated by gravimetric method at different temperature range. The experiment solubility increases with increase in temperature in both pure and binary solvents. The Maximum solubility is found in DMF at 328.15 K and for binary solvent mixture i.e. 1-propanol and THF (0.9 mol fraction) it was maximum at 318.15 K. Further modified Apelblate and Buchowski-Ksiazczak models were used for the theoretical calculation of solubility of BHBC in pure as well binary solvents. A satisfactory correlation of these models with experimental data was observed. The solution thermodynamics parameters like enthalpies, Gibb's free energy of dissolution and entropy of solutions were calculated using Van't Hoff and Gibb's equation, which reveals the solvation mechanism is non-spontaneous and entropy driven.     

Mean activity coefficient measurement and thermodynamic modelling of the ternary mixed electrolyte (MgCl2 + glucose + water) system at T = 298.15 K

In this work, the mean activity coefficients of MgCl₂ in pure water and (glucose + water) mixture solvent were determined using a galvanic cell without liquid junction potential of type: (Mg²⁺ + ISE)|MgCl₂ (m), glucose (wt.%), H₂O (100 wt.%)|AgCl|Ag. The measurements were performed at T = 298.15 K. Total ionic strengths were from (0.0010 to 6.0000) mol · kg⁻¹. The various (glucose + water) mixed solvents contained (0, 10, 20, 30 and 40)% mass fractions percentage of glucose respectively. The mean activity coefficients measured were correlated with Pitzer ion interaction model and the Pitzer adjustable parameters were determined. Then these parameters were used to calculate the thermodynamics properties for under investigated system. The results showed that Pitzer ion interaction model can satisfactory describe the investigated system. The modified three-characteristic-parameter correlation (TCPC) model was applied to correlate the experimental activity coefficient data for under investigation electrolyte system, too.