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Graphical abstract Highlights • Iminodibenzyl solubility in four cosolvent + water mixtures was determined. • Iminodibenzyl solubility was correlated using the Jouyban-Acree model. • Preferential solvation of iminodibenzyl was studied by using the IKBI method. Abstract The mole fraction solubility of bioactive iminodibenzyl in aqueous co-solvent mixtures of ethanol, ethylene glycol (EG), dimethyl sulfoxide (DMSO) and isopropanol was examined by the saturation shake-flask method over the temperature range from 283.15 K to 328.15 K at pressure of 101.2 kPa. The experimental solubility increased with increasing temperature at a given co-solvent composition and decreased with the increasing mass fraction of water in each binary system. The maximum solubility was found in pure co-solvent. Given the same temperature and mass fraction of the co-solvent, the solubility of iminodibenzyl was greater in (DMSO + water) than in the other three co-solvent systems. The solid crystal examples of iminodibenzyl was tested by X-ray power diffraction showing no polymorphic transformation, solvate formation or crystal transition during entire experiments. The Jouyban-Acree model was employed to correlate the measured solubility. The calculated data were in alignment to measured values and RAD and RMSD data were no more than 3.08% and 10.37 × 10−4, respectively. Furthermore, quantitative values for the local mole fraction of ethanol (EG, DMSO or isopropanol) and water around the iminodibenzyl were acquired by using the Inverse Kirkwood–Buff integrals method. The preferential solvation parameters for ethanol, EG, DMSO or isopropanol were positive in the four co-solvent mixtures in intermediate and co-solvent-rich compositions, which indicated that iminodibenzyl was preferentially solvated by the co-solvent. iminodibenzyl could act mainly as a Lewis acid interacting with proton-acceptor functional groups of the co-solvents. [ABSTRACT FROM AUTHOR]

The equilibrium solubility of ribavirin in solvent mixtures of {methanol (1) + water (2)}, { n -propanol (1) + water (2)}, {acetonitrile (1) + water (2)} and {1,4-dioxane (1) + water (2)} was determined experimentally by using isothermal dissolution equilibrium method within the temperature range from (278.15 to 318.15) K under atmospheric pressure (101.1 kPa). At the same temperature and mass fraction of methanol ( n -propanol, acetonitrile or 1,4-dioxane), the mole fraction solubility of ribavirin is greater in (methanol + water) than in the other three solvent mixtures. The preferential solvation parameters were derived from their thermodynamic solution properties by means of the inverse Kirkwood–Buff integrals. The preferential solvation parameters for methanol, n -propanol, acetonitrile or 1,4-dioxane ( δx 1,3 ) were negative in the four solvent mixtures with a very wide compositions, which indicated that ribavirin was preferentially solvated by water. Temperature had little effect on the preferential solvation magnitudes. The higher solvation by water could be explained in terms of the higher acidic behaviour of water interacting with the Lewis basic groups of the ribavirin. Besides, the solubility of the drugs was mathematically represented by using the Jouyban-Acree model, van’t Hoff-Jouyban-Acree model and Apelblat-Jouyban-Acree model obtaining average relative deviations lower than 1.57% for correlative studies. It is noteworthy that the solubility data presented in this work contribute to expansion of the physicochemical information about the solubility of drugs in binary solvent mixtures and also allows the thermodynamic analysis of the respective dissolution and specific solvation process. [ABSTRACT FROM AUTHOR]

The preferential solvation parameters ( δx ) of Boscalid in solvent mixtures of ethanol (1) + ethyl acetate (2), and isopropanol (1) + ethyl acetate (2) were derived from their available solubility data by means of the inverse Kirkwood-Buff integrals method. The values of δx vary non-linearly with the solvent (1) proportion in the two solvent mixtures. For the ethanol (1) + ethyl acetate (2) system, the values of δx are negative in ethanol-rich and ethyl acetate-rich mixtures, but positive in intermediate compositions; for the isopropanol (1) + ethyl acetate (2) system, the values of δx are positive in ethyl acetate-rich mixtures and in intermediate compositions, but negative in isopropanol-rich mixtures. The δx values are positive indicating that Boscalid is preferentially solvated by ethyl acetate. The magnitude of the preferential solvation of Boscalid by ethyl acetate is higher in isopropanol (1) + ethyl acetate (2) mixtures than in ethanol (1) + ethyl acetate (2) mixtures at 298.15, 308.15 and 313.15 K. The ethyl acetate action may be related to the disordered structure of ethanol or isopropanol molecules around the polar moieties of Boscalid, which increases the solvation, with maximum values near x = 0.40-0.45 for the two solvent mixtures. [ABSTRACT FROM AUTHOR]

Solvent effects on the decomposition of formic acid over a Co(111) surface were studied via density functional theory calculations combined with a continuum implicit solvation model. The solvents used here were water, methanol, and acetone. The adsorption energies of key intermediates, the activation barriers and the rate and equilibrium constants of various elementary reactions in vacuum and in the solvents were obtained. Solvent presences decrease the adsorption energies of species. Formic acid decomposition on the surface goes through HCOO rather than COOH both in vacuum and in the solvents. The most favorable decomposition pathways in vacuum and in acetone are HCOOH → HCOO → HCO → CO. The corresponding rate determining steps are HCOO deoxidation to HCO with activation barriers of 0.78 and 0.76 eV, respectively. In the presences of water and methanol, the preferred pathways are shifted to HCOOH → HCOO → HCOO- m → CO 2 below 750–800 K. Above those temperatures, the path of HCOOH → HCOO → HCO → CO becomes dominant again. [ABSTRACT FROM AUTHOR]

The preferential solvation parameters ( δx 1,3 ) of diazepam in binary solvent mixtures of {ethanol (1) + water (2)}, {propylene glycol (1) + water (2)}, {NMP (1) + water (2)} and {1,4-dioxane (1) + water (2)} at 298.2 K and { tert -butanol (1) + water (2)} at (299.2–313.2) K were derived from their available solubility values by using the inverse Kirkwood–Buff integrals method. The values of δx 1,3 vary non-linearly with the co-solvent (1) proportion in all the aqueous mixtures. For the former four co-solvent mixtures, the preferential solvation magnitude of diazepam by the co-solvent is highest in {1,4-dioxane (1) + water (2)} mixtures and lowest in {ethanol (1) + water (2)} mixtures. For the former four systems, the values of δx 1,3 are negative in water-rich mixtures, which indicates that diazepam could act as a Lewis base to establish hydrogen bonds with the proton-donor functional groups of the co-solvents (1) (with the exception of 1,4-dioxane). The same behaviour was also observed for ethanol (1) + water (2) mixtures with co-solvent-rich composition. In the {ethanol (1) + water (2)} mixtures with composition 0.241 < x 1 < 0.688, {NMP (1) + water (2)} mixtures with composition 0.164 < x 1 < 1.0, {propylene glycol (1) + water (2)} mixtures with composition 0.20 < x 1 < 1.0 and {1,4-dioxane (1) + water (2)} mixtures with composition 0.175 < x 1 < 1.0, diazepam is preferentially solvated by co-solvent. Some differences between the behaviours of diazepam in { tert -butanol (1) + water (2)} mixtures and the other four co-solvent mixtures were found. [ABSTRACT FROM AUTHOR]

The preferential solvation parameters ( δx 1,3 ) of rosmarinic acid in binary solvent mixtures of ethanol + water and methanol + water were derived from their thermodynamic properties by means of the inverse Kirkwood–Buff integrals method. δx 1,3 was negative in water-rich mixtures but positive in solvent compositions from 0.20 or 0.24 to 1 in mole fraction of methanol or ethanol, respectively. It was conjecturable that in water-rich mixtures, the hydrophobic hydration around the nonpolar aromatic groups of rosmarinic acid played a relevant role in the solvation. The higher solvation by methanol or ethanol in mixtures of similar co-solvent compositions could be mainly due to polarity effects. The preference of rosmarinic acid in intermediate compositions and in methanol-rich or ethanol-rich mixtures could be explained in terms of the higher acidic behavior of rosmarinic acid molecules interacting with the hydrogen acceptor groups in methanol or ethanol. The calculations were required in the pharmaceutical and chemical industries to save time and money in the optimization of the solubilization and/or crystallization process designs. [ABSTRACT FROM AUTHOR]

The preferential solvation parameters ( δx 1,3 ) of dehydroepiandrosterone acetate (DHEA acetate) in three co-solvent mixtures of methanol (1) + ethyl acetate (2), ethanol (1) + ethyl acetate (2), and isopropanol (1) + ethyl acetate (2) were derived from their available solubility data by means of the inverse Kirkwood–Buff integrals method. The values of δx 1,3 vary non-linearly with the co-solvent (1) proportion in all the co-solvent mixtures. For the studied systems, the values of δx 1,3 are negative in alcohol-rich mixtures, but positive in ethyl acetate-rich mixtures. The preferential solvation magnitude of DHEA acetate by the ethyl acetate is highest in {methanol (1) + ethyl acetate (2)} mixtures at 293.15 K and 303.15 K. While at 313.15 K, it is highest in {isopropanol (1) + ethyl acetate (2)} mixtures. The δx 1,3 values are positive indicating that DHEA acetate is preferentially solvated by ethyl acetate. The co-solvent action may be related to the disordered structure of ethyl acetate molecules around the non-polar moieties of DHEA acetate which increases the solvation having maximum values near to x 1 = 0.25–0.35 for the three co-solvent mixtures. [ABSTRACT FROM AUTHOR]

The preferential solvation parameters ( δx 1,3 ) of pioglitazone hydrochloride in four binary solvent mixtures of {ethanol (1) + water (2)}, { N -methyl pyrrolidone (NMP) (1) + water (2)}, {propylene glycol (1) + water (2)} and { N , N -dimethylsulfoxide (DMSO) (1) + water (2)} were derived from their available solubility data by means of the inverse Kirkwood–Buff integrals method. The values of δx 1,3 vary non-linearly with the co-solvent (1) proportion in all the aqueous mixtures. The preferential solvation magnitude of pioglitazone hydrochloride by the co-solvent is highest in {ethanol (1) + water (2)} mixtures and lowest in {propylene glycol (1) + water (2)}. For the systems of (ethanol + water) and (NMP + water), the values of δx 1,3 are negative in water-rich mixtures and co-solvent-rich mixtures, but positive in intermediate compositions. However, for the {propylene glycol (1) + water (2)} and {DMSO (1) + water (2)} mixtures with composition 0.20 < x 1 < 1, the δx 1,3 values are positive indicating that pioglitazone hydrochloride is preferentially solvated by co-solvent. The positive δx 1,3 values could be explained based on the higher acidic behaviour of pioglitazone hydrochloride molecules interacting with the hydrogen acceptor groups present in co-solvent. [ABSTRACT FROM AUTHOR]

• Solubility of 5-nitrosalicylaldehyde in four solvent mixtures was determined and correlated. • Preferential solvation of 5-nitrosalicylaldehyde in four mixtures were derived by IKBI method. • Studies on solvent effect were performed in terms of solute–solvent and solvent–solvent interactions. The equilibrium 5-nitrosalicylaldehyde solubility in methanol (1) + water (2), ethanol (1) + water (2), isopropanol (1) + water (2) and acetonitrile (1) + water (2) mixtures was determined by a shake-flask method from 273.15 K to 313.15 K under local pressure of 101.2 kPa. At the same mass fraction of methanol (ethanol, isopropanol or acetonitrile) and temperature, the mole fraction solubility of 5-nitrosalicylaldehyde was greater in (acetonitrile + water) mixture than in ethanol (1) + water (2), isopropanol (1) + water (2) and methanol (1) + water (2) mixtures. The relative importance of solute–solvent and solvent–solvent interactions upon the solubility variation was valued by using the linear solvation energy relationship analysis of solvent effect. The method of inverse Kirkwood–Buff integrals was used to study the preferential solvation on the basis of thermodynamic solution properties. The preferential solvation parameters for methanol, ethanol, isopropanol and acetonitrile were positive in the four mixtures in co-solvent-rich and intermediate composition, indicating that 5-nitrosalicylaldehyde was solvated preferentially by the co-solvent. It is conjecturable that in these regions 5-nitrosalicylaldehyde acts as a Lewis acid with the alcohols' molecules; while for the acetonitrile + water mixture, the preferential solvation could be attributed to polarization effects. Moreover, the drugs' solubility was mathematically represented via the Jouyban-Acree model acquiring the average relative deviations<6.03%. [ABSTRACT FROM AUTHOR]

Graphic abstract Highlights • Solubility of gimeracil (form P) in four co-solvent mixtures was determined and correlated. • Solvent effect analysis was performed according to experimental solubility data. • Preferential solvation of gimeracil (form P) were derivative by IKBI method. Abstract Solubilities of gimeracil (form P) in aqueous co-solvent mixtures of isopropanol, N,N -dimethylformamide (DMF), ethylene glycol (EG) and dimethylsulfoxide (DMSO) were investigated via the isothermal dissolution equilibrium method at (283.15–328.15) K under ambient pressure p = 101.2 kPa. Experimental solubility was increased with increasing temperature and mass fraction of each co-solvent. The largest solubility was found in neat co-solvents. The solids equilibrated with liquid phase were characterized by X -ray power diffraction, indicating no polymorphic transformation, solvate formation or crystal transition according to the spectral data. The Jouyban-Acree model was adopted to correlate the obtained solubility. The highest RAD and RMSD values were, respectively, 2.61 × 10−2 and 14.96 × 10−4. Quantitative values for the local mole fraction of DMF (EG, DMSO or isopropanol) and water around gimeracil (form P) were acquired by using the Inverse Kirkwood–Buff integrals method. The preferential solvation parameters for isopropanol were positive in the isopropanol mixtures in intermediate and isopropanol-rich compositions, which indicated that gimeracil (form P) was preferentially solvated by isopropanol. Gimeracil (form P) could act mainly as a Lewis acid interacting with proton-acceptor functional group of isopropanol. Within the same region, gimeracil (form P) was not preferentially solvated by DMF, EG and DMSO. Furthermore, the method of linear solvation energy relationships was performed with a suitable combination of solvent polarity descriptors to explain the nature of intermolecular interactions resulting in the solubility variation in the co-solvent mixtures. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Solubility of chlorhexidine in four cosolvent mixtures was determined and correlated. • Solvent effect was studied based on solute-solvent and solvent-solvent interactions. • Preferential solvation of chlorhexidine in mixtures were derived by IKBI method. Abstract The equilibrium solubilities of chlorhexidine in four solvent mixtures of methanol (1) + water (2), ethanol (1) + water (2), DMF (1) + water (2) and 1,4-dioxane (1) + w water (2) at temperature range from (278.15 to 318.15) K were reported. At the same composition of methanol, ethanol, DMF or 1,4-dioxane and temperature, the mole fraction solubility of chlorhexidine was highest in DMF (1) + w water (2) mixtures, and lowest in ethanol (1) + w water (2) mixtures. By using the Jouyban-Acree model, van't Hoff-Jouyban-Acree model and Apelblat-Jouyban-Acree model, chlorhexidine solubility was well correlated obtaining RAD lower than 1.69% and RMSD lower than 0.87 × 10−4. The dissolution process of chlorhexidine in solvent solutions was endothermic for the dissolution process. To study the solvent effect, solubility data were correlated to KAT parameters and cavity term on the basis of linear solvation energy relationships concept. Results indicate the key effect of cavity term and π ∗ in aqueous methanol and ethanol mixtures; cavity term in aqueous DMF mixtures; and cavity term, β and π ∗ in aqueous 1,4-dioxan mixtures. Quantitative values for the local mole fraction of methanol (ethanol, DMF or 1,4-dioxane) and water around the chlorhexidine were computed by using the IKBI method applied to the determined solubility data. Chlorhexidine was preferentially solvated by water for the four solvent mixtures in water-rich compositions; while in intermediate and co-solvent-rich composition for ethanol (DMF, 1,4-dioxane) (1) + w water (2) mixtures, chlorhexidine is preferentially solvated by the co-solvent. The preferential solvation magnitude of chlorhexidine was highest in 1,4-dioxane mixtures than in the other three solvent mixtures. [ABSTRACT FROM AUTHOR]

• Solubility of maraviroc in four co-solvent mixtures was determined and correlated. • Preferential solvation of maraviroc in four mixtures were derived through IKBI method. • Solvent effect was studied in terms of solvent–solvent and solute–solvent interactions. The liquid–solid equilibrium and solubility of maraviroc in co-solvent mixtures of n -propanol, ethanol, dimethyl sulfoxide (DMSO) and N,N -dimethylformamide (DMF) plus water was obtained via the saturation shake-flask technique between 278.15 K and 323.15 K under 101.2 kPa. For the four aqueous co-solvent mixtures investigated, the mole fraction solubility of maraviroc increased with the increase in the temperature and mass fraction of n -propanol, ethanol, DMSO and DMF. The maximum solubility values of maraviroc were observed in the neat co-solvents. The dependence of the maraviroc solubility on the solvent composition and temperature was mathematically correlated by means of the Jouyban-Acree model. The obtained values of relative average deviation (RAD) and root-mean-square deviation (RMSD) were no more than 4.16 × 10−2 and 49.13 × 10−6 , respectively. KAT-LSER model was implemented to get quantitative information about solvent effect on the variation of solubility data. The variation in the maraviroc solubility was dependent upon the hydrogen-bond donation and cavity term in n -propanol + water and ethanol + water mixtures; and the cavity term was the dominant term in the (DMSO + water) and (DMF + water) mixtures. Quantitative study was made for the local mole fraction of ethanol (n -propanol, DMSO and DMF) and water around the maraviroc by the Inverse Kirkwood–Buff integrals method applied to the solubility data determined. Maraviroc was preferentially solvated by ethanol or n -propanol for the aqueous co-solvent mixtures of ethanol or n -propanol in intermediate and ethanol/ n -propanol-rich compositions. It was conjecturable that maraviroc could act mainly as a Lewis acid in front to the ethanol or n -propanol molecules. However in the { n -propanol (1) + water (2)} mixture with compositions 0 < x 1 < 0.20, ethanol (1) + water (2) mixture with compositions 0 < x 1 < 0.25 and DMF/DMSO mixtures within entire compositions, maraviroc was preferentially solvated neither by co-solvent (1) nor by water. [ABSTRACT FROM AUTHOR]