Inverse Kirkwood Buff Integrals Method Research Articles

Solubility and preferential solvation of econazole nitrate in binary solvent mixtures of methanol, ethanol and 1,4-dioxane in water

The solubility of econazole nitrate in binary mixed solvents of (methanol+water, ethanol+water and 1,4-dioxane+water) were measured experimentally via the isothermal dissolution equilibrium method in the temperature range of (278.15–318.15) K under 101.2kPa. For the (1,4-dioxane+water) system, at a certain composition of 1,4-dioxane, the solubility of econazole nitrate increased with an increase in temperature; nevertheless at the same temperature, they increased at first and then decreased with an increase in mass fraction of 1,4-dioxane. At the same temperature and mass fraction of methanol, ethanol or 1,4-dioxane, the solubility of econazole nitrate was greater in (methanol+water) than in the other two mixed solvents. The solubility values were correlated by using Jouyban-Acree model, and the dissolution enthalpies of the dissolution process were computed. Preferential solvation parameters of econazole nitrate were also derived by means of the inverse Kirkwood-Buff integrals method. The preferential solvation parameter by water δx1,3 is negative in water-rich mixtures but positive in compositions from 0.31 to 1.0 in mole fraction of methanol and from 0.24 to 1.0 in mole fraction of ethanol. It is conjecturable that in intermediate composition of alcohol and alcohol-rich mixtures the interaction by acidic hydrogen-bonding by methanol/ethanol on the basic sites of econazole nitrate played a relevant role in the drug solvation. However in 1,4-dioxane (1)+water (2) mixtures with 0.18<x1<0.50 positive δx1,3 values were observed, but with 0.50<x1<1.0 negative δx1,3 values were observed again. The solubility data presented in this work expand the physicochemical information about drugs in binary aqueous-co-solvent mixtures.

Preferential solvation of dehydroepiandrosterone acetate in (co-solvent + ethyl acetate) mixtures according to the inverse Kirkwood–Buff integrals method

The preferential solvation parameters (δx1,3) 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 δx1,3 vary non-linearly with the co-solvent (1) proportion in all the co-solvent mixtures. For the studied systems, the values of δx1,3 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 293.15K and 303.15K. While at 313.15K, it is highest in {isopropanol (1)+ethyl acetate (2)} mixtures. The δx1,3 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 x1=0.25–0.35 for the three co-solvent mixtures.

Preferential solvation of pioglitazone hydrochloride in some binary co-solvent mixtures according to the inverse Kirkwood–Buff integrals method

The preferential solvation parameters (δx1,3) 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 δx1,3 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 δx1,3 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<x1<1, the δx1,3 values are positive indicating that pioglitazone hydrochloride is preferentially solvated by co-solvent. The positive δx1,3 values could be explained based on the higher acidic behaviour of pioglitazone hydrochloride molecules interacting with the hydrogen acceptor groups present in co-solvent.

PREFERENTIAL SOLVATION OF L-ARABINOSE AND DL-MALIC ACID IN ETHANOL + WATER MIXTURES

Utilizando algunas propiedades termodinámicas clásicas de disolución se calcularon los parámetros de solvatación preferencial dx1,3) de L-arabinosa y ácido DL-málico en mezclas etanol + agua mediante el método de las integrales inversas de Kirkwood-Buff (IKBI, por sus siglas en inglés); estos parámetros dx1,3 corresponden a las diferencias entre las fracciones molares locales alrededor del soluto y en el grueso de la solución. Se observó que estos compuestos son sensibles a efectos específicos de solvatación según la composición de la mezcla cosolvente. Así, los valores de dx1,3 para la L-arabinosa son positivos en mezclas ricas en agua pero negativos en composiciones desde 0.25 en fracción molar de etanol hasta el etanol puro. Sin embargo, en el caso del ácido DL-málico los valores de dx1,3 son negativos en todas las composiciones cosolventes analizadas. En mezclas ricas en agua la mayor solvatación de la L-arabinosa por parte de las moléculas de etanol podría deberse principalmente a efectos de polaridad. De otro lado, la preferencia que manifiestan ambos compuestos por el agua en mezclas ricas en etanol, podría explicarse en términos de la mayor acidez del agua, la cual estaría interactuando con los grupos aceptores de hidrógeno presentes en los dos solutos.

Solubility and preferential solvation of some n-alkyl-parabens in methanol + water mixtures at 298.15 K

Methyl, ethyl and propyl parabens equilibrium solubility was determined in (methanol+water) binary mixtures at 298.15K. The mole fraction solubility of these compounds increased in 503 (from 2.40×10−4 to 0.121), 1377 (from 9.86×10−5 to 0.136) and 4597 (from 3.73×10−5 to 0.171) times when passing from neat water to neat methanol, for methyl, ethyl and propyl parabens, respectively. All these solubility values were correlated with the Jouyban-Acree model. Preferential solvation parameters by methanol (δx1,3) of these parabens were derived from their thermodynamic solution properties using the inverse Kirkwood-Buff integrals (IKBI) method. For all compounds δx1,3 values are negative in water-rich mixtures but positive in mixtures with methanol mole fraction greater than 0.32. It is conjecturable that in the former case the hydrophobic hydration around non-polar groups of parabens plays a relevant role in the solvation. Besides, the preferential solvation of these solutes by methanol in mixtures of similar co-solvent compositions and in methanol-rich mixtures could be explained in terms of the higher basic behaviour of methanol.

Solution thermodynamics and preferential solvation of 3-chloro-N-phenyl-phthalimide in acetone + methanol mixtures

The thermodynamic properties of the 3-chloro-N-phenyl-phthalimide in acetone+ methanol cosolvent mixtures were obtained from solubility data report in literature. The solubility was higher in near acetone and lower in pure methanol at all temperatures studied. A non-linear plot of ∆ from pure acetone up to x 1 soln H° vs. ∆ soln 2, Gerson G° shows a negative slope = 0.691. Beyond this composition, a variable positive slope is obtained with the exception of mixtures with x 1 = 0.121, x1 = 0.272 and x 1= 0.356 which is a not common trend in these systems. The preferential solvation of 3-chloro-N-phenyl-phthalimide by the components of the solvents was estimated by means of the inverse Kirkwood–Buff integral method, showing the 3-chloro-Nphenyl-phthalimide is preferential solvated bymethanol in more polar mixtures and by acetone in less polar ones.

Further Numerical Analyses on the Solubility of Sulfapyridine in Ethanol + Water Mixtures

Background: Dissolution thermodynamic quantities of sulfapyridine (SP) have been reported in the literature for aqueous alcoholic mixtures. Nevertheless, no attempts to evaluate the preferential solvation of this drug in this binary system, have been reported. In this way, the inverse Kirkwood-Buff integrals (IKBI) were used to evaluate this behavior in solution. Methods: Solubility data for SP dissolved in binary ethanol (EtOH) + water mixtures at various temperatures were mathematically represented using the Jouyban-Acree (J-A) model. The preferential solvation parameters of SP by EtOH (δx1,3) in EtOH + water mixtures were obtained from some thermodynamic properties of the mixtures by means of the IKBI method. Results: Solubility of SP in EtOH + water mixtures is adequately described by the J-A model in second order. Moreover, SP is sensitive to specific solvation effects, so the δx1,3 values are negative in water-rich and EtOH-rich mixtures indicating preferential solvation by water in these mixtures. By contrary, δx1,3 values are positive in the range 0.24 < x1 < 0.53 indicating preferential solvation by EtOH in these mixtures. Conclusion: It can be assumed that in water-rich mixtures the hydrophobic hydration around the aromatic rings plays a relevant role in the solvation. The higher drug solvation by EtOH in mixtures of similar solvent proportions could be due to polarity effects. Moreover, in EtOH + water mixtures SP could be acting as a Lewis acid with the EtOH molecules and in EtOH-rich mixtures the drug could be acting as a Lewis base with water molecules.

Solubility, solution thermodynamics, and preferential solvation of piroxicam in ethyl acetate + ethanol mixtures

The solubility of piroxicam (PIR) in ethyl acetate (EtOAc)+ethanol (EtOH) mixtures at five temperatures from 293.15K to 313.15K was determined and the solubility data in the binary solvent mixtures at various temperatures was mathematically represented using the Jouyban–Acree model. PIR solubility in mole fraction varied from x3=1.77×10−4 in pure EtOH to x3=4.97×10−3 in pure EtOAc at 298.15K, reaching a maximum x3=5.69×10−3 in the mixture with x10=0.80. Thermodynamic quantities of dissolution and mixing of PIR were calculated by means of Gibbs and van't Hoff equations. Furthermore, preferential solvation parameters of PIR were also derived by means of the inverse Kirkwood–Buff integrals method. The preferential solvation parameter of PIR by EtOAc, δx1,3, is negative in EtOH-rich mixtures but positive in compositions from 0.36 to 0.86 in mole fraction of EtOAc. It is possible that in EtOH-rich mixtures the acidic hydrogen bonding of EtOH with the basic sites of PIR plays an important role in the drug solvation. The greater solvation by EtOAc in mixtures of similar solvent compositions could be owing mainly to polarity effects. Finally, the slight preference of PIR for EtOH in EtOAc-rich mixtures could be explained in terms of the common participation of basic sites in both solvents and/or the acidic site of EtOH with the respective functional groups of PIR.

Further numerical analysis on the solubility of ibrutinib in ethanol + water mixtures at different temperatures

The main purpose of this communication was to expand the results of numerical analyses performed by Shakeel et al. on their experimental solubility of anti-cancer drug ibrutinib in ethanol+water mixtures at different temperatures, in terms of the solubility data modeling according to the Jouyban–Acree model and also the evaluation of the preferential solvation of this drug by both solvents, ethanol and water, in the saturated mixtures, based on the inverse Kirkwood–Buff integrals method.

Solubility and preferential solvation of acetaminophen in methanol + water mixtures at 298.15 K

ABSTRACTThe equilibrium solubility of acetaminophen in methanol + water binary mixtures at 298.15 K was determined and correlated with the Jouyban–Acree model. Preferential solvation parameters by methanol (δx1,3) were derived from their thermodynamic solution properties by means of the inverse Kirkwood–Buff integrals method. δx1,3 values are negative in water-rich mixtures but positive in compositions from 0.32 in mole fraction of methanol to pure methanol. It is conjecturable that in the former case, the hydrophobic hydration around non-polar groups plays a relevant role in the solvation. The higher solvation by methanol in mixtures of similar cosolvent compositions and methanol-rich mixtures could be explained in terms of the higher basic behavior of this cosolvent.

Preferential solvation of indomethacin in 1,4-dioxane + water mixtures according to the inverse Kirkwood–Buff integrals method

ABSTRACTThe preferential solvation parameters (δx1,3) of indomethacin (IMC) in 1,4-dioxane + water binary mixtures were derived from their thermodynamic properties by means of the inverse Kirkwood–Buff integrals method. δx1,3 is negative in water-rich and 1,4-dioxane-rich mixtures but positive in cosolvent compositions from 0.17 to 0.69 in mole fraction of 1,4-dioxane at 298.15 K. It is conjecturable that in water-rich mixtures, the hydrophobic hydration around the aromatic and methyl groups of the drug plays a relevant role in the solvation. The higher solvation by 1,4-dioxane in mixtures of similar cosolvent compositions could be mainly due to polarity effects. Finally, the preference of this drug for water in 1,4-dioxane-rich mixtures could be explained in terms of the higher acidic behavior of water molecules interacting with the hydrogen-acceptor groups present in IMC.

Preferential Solvation of Indomethacin in Some Aqueous Co-Solvent Mixtures

The preferential solvation parameters for indomethacin (IMC) in ethanol (EtOH) + water and propylene glycol (PG) + water binary mixtures were obtained from their thermodynamic properties by means of the inverse Kirkwood–Buff integrals (IKBI) and the quasi-lattice quasi-chemical (QLQC) methods. According to IKBI method, the preferential solvation parameter by co-solvents, (δx1,3), is negative in the water-rich mixtures of both binary systems but positive in the other compositions at temperatures of 293.15, 303.15, and 313.15 K. It is conjecturable that in water-rich mixtures the hydrophobic hydration around the aromatic rings and methyl groups of the drug plays a relevant role in the solvation. The higher drug solvation by co-solvent in mixtures of similar solvent proportion and in co-solvent-rich mixtures could be due mainly to polarity effects. Here IMC would be acting as a Lewis acid with the EtOH or PG molecules because these co-solvents are more basic than water.

Solubility and preferential solvation of sulfadiazine, sulfamerazine and sulfamethazine in propylene glycol + water mixtures at 298.15 K

The equilibrium solubility of sulfadiazine, sulfamerazine and sulfamethazine in propylene glycol (PG)+water binary mixtures was determined at 298.15K and the preferential solvation parameters were derived from their thermodynamic solution properties by means of the inverse Kirkwood–Buff integrals method. It is found that these sulfonamides are sensitive to specific solvation effects. The preferential solvation parameters by PG (δx1,3) are negative in water-rich mixtures but positive in mixtures with compositions from 0.20 in mole fraction of PG to pure PG. It is conjecturable that in the former case the hydrophobic hydration around aromatic rings and/or methyl groups plays a relevant role in the solvation. The more solvation by PG in mixtures of similar co-solvent compositions and in PG-rich mixtures could be explained in terms of the bigger basic behavior of this co-solvent interacting with hydrogen-donor groups of the drugs.

Preferential Solvation of Ketoprofen in Some Co-solvent Binary Mixtures

The preferential solvation parameters of ketoprofen (KTP) in ethanol (EtOH) + water and propylene glycol (PG) + water binary solvent mixtures were obtained from their thermodynamic properties by means of the inverse Kirkwood–Buff integrals (IKBI) and quasi-lattice quasi-chemical methods. According to the IKBI method, it is found that KTP is very sensitive to specific solvation effects, so the preferential solvation parameter by co-solvents, δx 1,3, is negative in the water-rich mixtures of both binary systems but positive in the other compositions at temperatures of 293.15, 303.15 and 313.15 K. From this it can be assumed that, in water-rich mixtures, hydrophobic hydration around the aromatic rings and the methyl group, present in the drug, plays a relevant role in the solvation. The bigger amount of drug solvation by the co-solvent in mixtures of similar solvent proportions and in co-solvent-rich mixtures could be due mainly to polarity effects. Moreover, in these mixtures the solute will be acting as a Lewis acid with the co-solvent molecules, because they are more basic than water.

Solubility and Solution Thermodynamics of Meloxicam in 1,4-Dioxane and Water Mixtures

The equilibrium solubility of meloxicam in 1,4-dioxane and water binary mixtures at temperatures from 293.15 to 313.15 K was determined, and the respective thermodynamic quantities of solution were calculated. Additionally, the preferential solvation parameters of the drug were derived from their thermodynamic solution properties by means of the inverse Kirkwood–Buff integrals method. From solvent effect studies, it is found that this drug is sensitive to specific solvation effects. The preferential solvation parameter by 1,4-dioxane, δx1,3, is negative in water-rich mixtures but positive in compositions in which 0.18 < x1 < 1.00. It could be possible that in water-rich mixtures the hydrophobic hydration around aromatic rings and/or methyl groups plays a relevant role in the drug solvation. The greater solvation by 1,4-dioxane in mixtures of similar cosolvent compositions and 1,4-dioxane-rich mixtures could be explained in terms of the greater basic behavior of the cosolvent interacting with the hydrogen-...

Solubility and preferential solvation of meloxicam in ethyl acetate+ethanol mixtures at several temperatures

Abstract The equilibrium solubility of meloxicam (MEL) in ethyl acetate + ethanol mixtures at five temperatures from 293.15 K to 313.15 K was determined and the respective thermodynamic quantities of solution processes were calculated. Preferential solvation parameters of the drug were also derived by means of the inverse Kirkwood-Buff integrals method. The preferential solvation parameter by ethyl acetate δx1,3, is negative in ethanol-rich mixtures but positive in compositions from 0.38 to 0.80 in mole fraction of ethyl acetate. It is conjecturable that in ethanol-rich mixtures the interaction by acidic hydrogen-bonding by ethanol on the basic sites of MEL plays a relevant role in the drug solvation. The more solvation by ethyl acetate in mixtures of similar solvent compositions could be due mainly to polarity effects. Finally, the slight preference of this drug for ethanol in ethyl acetate-rich mixtures could be explained in terms of the common participation of basic sites in both solvents and/or the acidic site of ethanol with the respective counterparts of MEL.

Preferential solvation of some structurally related sulfonamides in 1-propanol + water co-solvent mixtures

The preferential solvation parameters by 1-propanol of sulfadiazine, sulfamerazine and sulfamethazine in 1-propanol + water mixtures were derived from their solution thermodynamic properties by means of the inverse Kirkwood–Buff integrals method. These sulfonamides are sensitive to solvation effects, so the preferential solvation parameter δx1,3 is negative in water-rich and 1-propanol-rich mixtures but positive in intermediate compositions. It is possible that the hydrophobic hydration around aromatic rings and/or other non-polar groups plays a relevant role in the solvation in water-rich mixtures. The more solvation by 1-propanol in mixtures of similar composition could be due mainly to polarity effects and acidic behaviour of the sulfonamides in front to the more basic solvent 1-propanol. Otherwise, the more solvation by water in 1-propanol-rich mixtures could be due to basic behaviour of the sulfonamides in front to water, which is the more acidic solvent.

Solubility and preferential solvation of meloxicam in methanol + water mixtures at 298.15 K

The equilibrium solubility of meloxicam in methanol+water binary mixtures at 298.15K was determined and the preferential solvation parameters were derived from their thermodynamic solution properties by means of the inverse Kirkwood–Buff integrals method. From solvent effect studies, it is found that this drug is sensitive to specific solvation effects. The preferential solvation parameter by methanol δx1,3, is negative in water-rich mixtures but positive in compositions from 0.30 in mole fraction of methanol to pure methanol. It is conjecturable that in the former case the hydrophobic hydration around aromatic rings and/or methyl groups plays a relevant role in the solvation. The more solvation by methanol in mixtures of similar co-solvent compositions and in methanol-rich mixtures could be explained in terms of the bigger basic behavior of the co-solvent interacting with hydrogen-donor groups of the drug.

Solvatación preferencial de algunas sulfonamidas en mezclas cosolventes 1,4-dioxano + agua a 298,15 K según el método de las integrales inversas de Kirkwood-Buff

The preferential solvation parameters, that is, the difference between the local and bulk mole fractions of the solvents in solutions of some structurally related sulfonamides in 1,4-dioxane + water binary mixtures are derived from their thermodynamic properties by means of the inverse Kirkwood-Buff integrals method. From solvent effect studies, it was found that all the sulfonamides considered were very sensitive to solvation effects, so the preferential solvation parameter, δxD,S, was negative in water-rich and 1,4-dioxane-rich mixtures but positive in intermediate co-solvent compositions. It may be possible that in water-rich mixtures the hydrophobic hydration around the non-polar groups plays a relevant role in the solvation. The greater solvation by 1,4-dioxane in mixtures of similar co-solvent compositions could be due mainly to polarity effects. Finally, the preference of these drugs for water in 1,4-dioxane-rich mixtures could be explained in terms of the acidic behavior of water interacting with the hydrogen-acceptor groups in the sulfonamides.

Preferential Solvation of Acetaminophen in Propylene Glycol + Water Co-Solvent Mixtures

The preferential solvation parameters defined as the differences between the local mole fraction of solvents around analgesic drug acetaminophen and those for the bulk co-solvent composition in propylene glycol + water mixtures were derived from their thermodynamic properties by means of the inverse Kirkwood-Buff integrals (IKBI) and the quasi-lattice-quasi-chemical (QLQC) methods. It is found that acetaminophen is sensitive to solvation effects, so according to IKBI method the preferential solvation parameter δ´xPG,A, is negative in water-rich mixtures but positive in medium compositions and in co-solvent-rich mixtures. It is conjecturable that in water-rich mixtures the hydrophobic hydration around the aromatic ring and methyl group present in the drug plays a relevant role in the solvation. The bigger drug solvation by co-solvent in mixtures of similar solvent proportions and in propylene glycol-rich mixtures could be due mainly to polarity effects. Otherwise, according to QLQC method, this drug is preferentially solvated by the co-solvent in all the mixtures.