Average Relative Deviation Values Research Articles

Equilibrium solubility, thermodynamic properties and Hansen solubility parameter of doxifluridine in (±)-2-ethyl-1-hexanol + (methanol, ethanol and acetone) at various temperatures

The solubility values of doxifluridine in three mixed solvents of (±)-2-ethyl-1-hexanol + (methanol, ethanol and acetone) ware determined within 278.15–328.15 K under 0.1 MPa using a laser monitoring technique. It can be seen from the solubility profiles that all the solubility of doxifluridine in the mixed solvents increases with the increasing mass fraction of the co-solvent (methanol, ethanol or acetone) and the experimental temperature. The minimum and maximum mole fraction solubility of doxifluridine was found in ethanol + (±)-2-ethyl-1-hexanol (4.981 × 10−5 at w1 = 0.1003, T = 278.15 K) and methanol + (±)-2-ethyl-1-hexanol (1.109 × 10−1 at w1 = 0.9001, T = 328.15 K), respectively. Through the application of Hansen solubility parameters, the solubility order and miscibility of doxifluridine in the three mixed solvents studied in this work was revealed, and the results showed that the dissolution behavior of doxifluridine was not only determined by a single factor, but also the result of the comprehensive action of various solubility parameters. In addition, three semi-empirical models (λh, Modified Apelblat, and MA) and one activity coefficient model (UNIQUAC) were applied to fit the solubility data of doxifluridine. The minimum average values of ARD (average relative deviation) and 104 RMSD (root-mean square deviation) were acquired from Modified Apelblat model, verifying that Modified Apelblat model provides maximum consistency among the four models. Furthermore, Van't Hoff model was used to calculate the apparent thermodynamic parameters (ΔsolG°, ΔsolH°, ΔsolS°) of the dissolution process of doxifluridine. The results demonstrated that the dissolution process of doxifluridine in all the three mixed solvents studied was an entropy-driven endothermic process.

Solubility, Hansen solubility parameter and thermodynamic properties of etodolac in twelve organic pure solvents at different temperatures

In this article, the solubility of etodolac in n-propanol, n-butanol, isopropanol, isobutanol, methyl acetate, n-butyl acetate, n-amyl acetate, isobutyl acetate, isoamyl acetate, toluene, acetone at 278.15 K–323.15 K and dichloromethane at 278.15 K–303.15 K under the pressure of 0.1 MPa was studied using a laser monitoring technology. The experimental results show that the solubility of etodolac in all the 12 pure solvents is positively correlated with the temperature. The van't Hoff model, Apelblat model, λh model, NRTL model and UNIQUAC model were used to fit the etodolac solubility data. Through comparison, it was found that the Apelblat model has the smallest average values of ARD (average relative deviation) and RMSD (root-mean square deviation), and the average values of ARD% and 104 RMSD were 0.92% and 5.99, respectively. The result shows that the Apelblat model was more suitable for correlating the solubility data. The order of solubility of etodolac was analyzed by using Hansen solubility parameter, and the solvent effect was studied by calculating the KAT-LSER parameter. Besides, the thermodynamic properties of the solution process of etodolac were calculated and analyzed by the van't Hoff analysis. The results show that the dissolution process of etodolac is endothermic and entropy-driven.

Equilibrium Solubility and Dissolution Property Analysis of 2-Nitrophenylacetic Acid in 13 Pure Solvents at Elevated Temperatures

This work was devoted to the equilibrium solubility of 2-nitrophenylacetic acid in 13 neat solvents ethylene glycol (EG), methanol, ethanol, acetonitrile, n-propanol, isopropanol, water, n-butanol, N,N-dimethylformamide (DMF), isobutanol, cyclohexane, ethyl acetate, and 1,4-dioxane ranging from 283.15 to 328.15 K. All determinations were made by the shake-flask technique at a pressure of p = 101.2 kPa. The mole fraction solubility magnitudes of 2-nitrophenylacetic acid increased gradually with the rising investigated temperature and presented a decreasing trend in the 13 neat solvents: DMF > (1,4-dioxoane, methanol) > ethanol (ethyl acetate) > n-propanol > n-butanol > isopropanol > EG > acetonitrile > isobutanol > water > cyclohexane. The method of linear solvation energy relationships was employed here to inspect the solvent–solvent and solute–solvent interactions. The solvent descriptors of the Hildebrand solubility parameter and polarizability/dipolarity presented great influence upon the solubility magnitudes of the solute 2-nitrophenylacetic acid. The obtained solubility values in mole fraction were correlated mathematically via four models/equations, namely, λh, non-random two-liquid, Apelblat, and Wilson. The maximum value of relative average deviation (RAD) was 3.68 × 10–2, and the maximum value of root-mean-square deviations was 116.78 × 10–4. The RAD values by using the Apelblat equation were smaller than that by using the other equations/models for a fixed solvent. Additionally, the dissolution properties, activity coefficient, and reduced excess enthalpy under the conditions of infinite dilution were obtained through the Wilson model.

Equilibrium solubility, preferential solvation and solvent effect study of clotrimazole in several aqueous co-solvent solutions

The equilibrium solubility of clotrimazole in co-solvent mixtures of n-propanol/isopropanol/acetonitrile/1,4-dioxane + water was attained by the saturation shake-flask technique at temperatures between 278.15 K and 323.15 K under ambient pressure of 101.2 kPa. The solubility of clotrimazole in mole fraction scale increased with increasing temperature and mass fractions of n-propanol/isopropanol/acetonitrile/1,4-dioxane. The maximum value was recorded in the neat co-solvent for each mixture studied. The Jouyban-Acree model and van’t Hoff-Jouyban-Acree model were applied to mathematically describe the dependence of clotrimazole solubility upon the co-solvent content and temperature, obtaining the values of relative average deviations and root-mean-square deviations no more than 8.02 × 10−2 and 8.17 × 10−4, individually. KAT-LSER model was implemented to quantitatively acquire evidence about solvent effect upon the variation of clotrimazole solubility magnitudes. The variation in clotrimazole solubility mainly depended upon the Hildebrand solubility parameter and dipolarity-polarizability of solutions in the four aqueous systems studied. Quantitative investigation was carried out for the local mole fractions of n-propanol/isopropanol/acetonitrile/1,4-dioxane and water around solute clotrimazole by using the Inverse Kirkwood–Buff integrals way utilized to the solubility data determined. Clotrimazole was preferentially solvated by n-propanol/isopropanol/acetonitrile/1,4-dioxane for these aqueous co-solvent mixtures in intermediate and n-propanol/isopropanol/acetonitrile/1,4-dioxane-rich proportions.

Griseofulvin dissolved in binary aqueous co-solvent mixtures of N,N-dimethylformamide, methanol, ethanol, acetonitrile and N-methylpyrrolidone: Solubility determination and thermodynamic studies

The equilibrium solubility of griseofulvin in five co-solvent mixtures of N,N-dimethylformamide (DMF) + water (2), methanol (1) + water (2) , ethanol (1) + water (2), acetonitrile (1) + water (2) and N-methylpyrrolidone (NMP) (1) + water (2) were acquired through experiment at temperatures covering from 278.15 K to 323.15 K by the saturation shake-flask technique. The maximum solubility appeared in the neat co-solvents of DMF/methanol/ethanol/acetonitrile/NMP for each mixture. The mole fraction solubility of griseofulvin in the five mixtures was well correlated via van’t Hoff–Jouyban-Acree model and Jouyban-Acree model acquiring values of relative average deviations<9.41% and root-mean-square deviations<10.30 × 10-4. The cavity term and KAT parameters correlated the mole fraction solubility in terms of the linear solvation energy relationships. The significant effect to the solubility variation was the cavity term and dipolarity-polarizability term in aqueous DMF/methanol/ethanol/acetonitrile/NMP mixtures. What's more, the quantitative magnitudes for local mole fractions of DMF/methanol/ethanol/acetonitrile/NMP and water around the drug griseofulvin were evaluated by using the Inverse Kirkwood–Buff integrals method applied to griseofulvin solubility. In the methanol (1) + water (2) mixture with compositions 0.31 < x1 < 1, ethanol (1) + water (2) mixture with compositions 0.25 < x1 < 1, DMF (1) + water (2) mixture with compositions 0.20 < x1 < 1, NMP (1) + water (2) mixture with compositions 0.16 < x1 < 1 and acetonitrile (1) + water (2) mixture with compositions 0.253 < x1 < 1, griseofulvin was preferentially solvated by DMF/methanol/ethanol/acetonitrile/NMP.

Equilibrium solubility of exo-5,6-dehydronorcantharidin in thirteen pure solvents: Determination, correlation, Hansen solubility parameter and thermodynamic properties

This research was focusing on determining the solid-liquid equilibrium solubility of exo-3,6-epoxy-1,2,3,6-tetrahydrophthalic acid anhydride (exo-5,6-dehydronorcantharidin) in thirteen mono-solvents by using laser monitoring approach at diverse temperature and pressure “p = 0.1 MPa”. The results showed that the solubility data of exo-5,6-dehydronorcantharidin in all solvents was positively correlated with experimental temperature. Besides, the mole-fraction solubility values of exo-5,6-dehydronorcantharidin in all considered solvents at “T = 298.15 K” were found maximum in N-methyl-2-pyrrolidinone (0.184) followed by N,N-Dimethylformamide (0.150), acetone (0.0629), acetonitrile (0.0508), methyl acetate (0.0420), 1,4-dioxane (0.0342), ethyl acetate (0.0275), n-propyl acetate (0.0210), isopropyl acetate (0.0191), butyl acetate (0.0172), isobutyl acetate (0.0165), amyl acetate (0.0137) and isoamyl acetate (0.0129). The polarity and Hansen solubility parameter of studied solvents were employed to reveal the affinity and solubility order of exo-5,6-dehydronorcantharidin, and the results indicated that the miscibility between solute and solvent relied on comprehensive effects of multiple factors. Moreover, the obtained solubility data was correlated with Wilson, NRTL, UNIQUAC and NRTL-SAC model. The correlation results showed that the UNIQUAC model can provide the best fitting effect with lower values of average relative deviation (ARD) and root-mean square deviation (RMSD). Finally, thermodynamic mixing and dissolution properties of exo-5,6-dehydronorcantharidin in thirteen neat solvents were calculated based on UNIQUAC model as well as experimental values.

Solubility of 3,5-Dinitrosalicylic Acid in Fourteen Pure Solvents over Temperatures from 278.15 to 323.15 K

Through the saturation shake-flask technique, the solubility of 3,5-dinitrosalicylic acid in 14 pure solvents such as ethylene glycol (EG), ethanol, n-propanol, ethyl acetate, isopropanol, acetonitrile, N,N-dimethylformamide (DMF), N-methyl-2-pyrrolidinone (NMP), n-butanol, isobutanol, dimethyl sulfoxide (DMSO), water, cyclohexane, and 1,4-dioxane was determined over the temperatures from 278.15 to 323.15 K at an ambient pressure of about p = 101.2 kPa. As the studied temperatures increased, the magnitude of mole fraction solubility of 3,5-dinitrosalicylic acid in the above pure solvents increased positively and followed the decreasing order as NMP > DMF > DMSO > ethanol > ethyl acetate > n-propanol > 1,4-dioxane > isopropanol > EG > isobutanol > n-butanol > acetonitrile > cyclohexane > water. The molecule interactions of solvent–solute and solvent–solvent were checked through a linear solvation energy relationship. The determined solubility was mathematically described by the Wilson model, Apelblat equation, NRTL model, and λh equation. The obtained root-mean-square deviation values and relative average deviation values were not greater than 52.93 × 10–4 and 6.04 × 10–2, respectively. Also, the mixing properties, reduced excess enthalpy, and activity coefficients at infinitesimal concentration were derived in terms of the Wilson equation.

Equilibrium solubility, thermodynamic properties and Hansen solubility parameter of N-hydroxy-5-norbornene-2,3-dicarboximide in ethyl acetate + (2-methoxyethanol, methanol and 1,4-dioxane) at various temperatures

Solubility of N -hydroxy-5-norbornene-2,3-dicarboximide (HONB) in three mixed solvents of ethyl acetate + (2-methoxyethanol, methanol and 1,4-dioxane) was investigated within 278.15 K–323.15 K under 0.1 MPa. The solubility profiles indicated that the HONB solubility in measured solvents was proportional to the increment of test temperature and mass fraction of positive solvent (2-methoxyethanol, methanol or 1,4-dioxane). The mole fraction solubility of HONB varied significantly from 0.0115 in ethyl acetate + 1,4-dioxane ( w 1 = 0.2066, 278.15 K) to 0.1788 in ethyl acetate + 2-methoxyethanol ( w 1 = 0.7993, 323.15 K). Hansen solubility parameter was applied to reveal the miscibility and solubility order of HONB in mixed solvents, and the consequences indicated that solubility behaviors of HONB were the result of various solubility parameters comprehensive action. The measured HONB solubility employing laser monitoring technique was correlated with four activity coefficient models (Three-Suffix Margules, NRTL, UNIQUAC and Wilson) in combination with a semi-empirical model (Modified Apelblat). The smallest average values of average relative deviation (ARD) and root-mean square deviation (10 4 RMSD) were obtained from Wilson (0.66%) and Modified Apelblat model (6.02), verifying that these two models provided more satisfactory agreement and correlation than other three models. Furthermore, the thermodynamic parameters (Δ mix H , Δ mix G and Δ mix S ) of the mixing process in different solvents were computed based on measured solubility values and equation parameters of Wilson model. The results demonstrated that the mixing process was entropy-driven and spontaneous. These solubility data and thermodynamic parameters could not merely extend database of HONB, but provide basic guidance for optimizing crystallization and purification process. • Solubility of HONB in three binary solvents was measured. • The miscibility and solubility order of HONB were revealed well by Hansen solubility parameter. • Thermodynamic modeling was realized by using the Margules, NRTL, UNIQUAC, Wilson and Modified Apelblat model. • Thermodynamic properties of mixing process were evaluated by Wilson model.

Effect of losartan and propranolol on cardiac remodeling in mucopolysaccharidosis type I mice

The purpose of this work was to measure the equilibrium solubility of naphazoline hydrochloride (NPZ) in different mono-solvents ranged from 278.15 K to 323.15 K by a laser monitoring method. In this research, N-methyl pyrrolidone (NMP), n-propanol, 2-butoxyethanol, ethanol, 2-methoxyethanol, N,N-dimethylformamide (DMF), methanol, ethylene glycol (EG), isopropanol, 2-propoxyethanol and 2-ethoxyethanol were selected as the experimental solvents. The results indicated that solubility data of NPZ in 11 neat solvents increased with the increase of temperature. At 298.15 K, the maximum solubility was observed in EG (5.028e-2), followed by 2-methoxyethanol (2.460e-2), methanol (2.429e-2), 2-ethoxyethanol (7.788e-3), ethanol (6.391e-3), 2-propoxyethanol (4.216e-3), n-propanol (3.373e-3), 2-butoxyethanol (3.144e-3), DMF (2.348e-3), NMP (2.002e-3) and isopropanol (1.689e-3). Moreover, the solvent polarity, radial distribution function (RDF) and solvent effect (KAT-LSER model) were implemented to investigate the impact of solute-solvent interactions on solubility behavior of NPZ. The results demonstrated that the whole dissolution behavior of NPZ in organic solvents was a complicated process, and the solvent-solute interactions were associated with hydrogen bond acidity and dipolarity/polarizability of solvent. Besides, the NRTL-SAC, Two-Suffix Margules, Wilson, NRTL and UNIQUAC models were employed to fit experimental solubility data. Deviation analysis revealed that the Wilson model reflected the best agreement between measured data and calculated values with the minimum mean values of average relative deviation (100ARD, 0.9144) and root-mean square deviation (104RMSD, 1.062). Furthermore, the positive entropy changes and negative values of Gibbs energy changes showed that mixing and dissolution process of NPZ in 11 neat solvents were confirmed to entropy-driven and spontaneous.

Maraviroc in aqueous co-solvent solutions of n-propanol, ethanol, dimethyl sulfoxide and N,N-dimethylformamide: Solubility determination, preferential solvation and solvent effect analysis

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 < x1 < 0.20, ethanol (1) + water (2) mixture with compositions 0 < x1 < 0.25 and DMF/DMSO mixtures within entire compositions, maraviroc was preferentially solvated neither by co-solvent (1) nor by water.

Determination and Calculation of Phase Equilibrium for Aqueous Ternary System (NH2)2CO+KCl+H2O at 283.15K

The solid-liquid phase equilibrium for ternary system (NH2)2CO+KCl+H2O was determined by isothermal saturation method at 283.15K under atmosphere pressure. The isothermal phase diagrams was drawn in according to the measured solubility data. There are one co-saturated point and two pure solids occurred in this ternary system. The solid phases were confirmed by Schreinemaker’s wet residue method and X-ray powder diffraction. Two thermodynamic models, Wilson model and NRTL model, were used to calculate the solubility data. The value of root mean-square deviation in Wilson model and NRTL model for this ternary system was 0.22 and 0.66 respectively, and the value of relative average deviation was 0.61% and 2.33% respectively, which indicated that the calculated data and the experimental results are nearly consistent.

Thermodynamic modelling and Hansen solubility parameter of N-hydroxy-5-norbornene-2,3-dicarboximide in twelve pure solvents at various temperatures

Solubility of N-hydroxy-5-norbornene-2,3-dicarboximide (HONB) in methanol, ethanol, n-propanol, isopropanol, 2-methoxyethanol, 2-propoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, acetonitrile, ethyl acetate, acetone at (278.15–323.15) K and 1,4-dioxane at (288.15–323.15) K was determined with a laser monitoring method at pressure of 0.1 MPa. The experimental results indicated that solubility of HONB increased positively with the increase of temperature in selected neat solvents. At 298.15 K, solubility data in studied solvents followed the sequence of 2-methoxyethanol (0.1412) > methanol (0.1108) > 2-ethoxyethanol (0.1007) > 1,4-dioxane (0.0963) > 2-propoxyethanol (0.0718) > 2-butoxyethanol (0.0601) > ethanol (0.0592) > acetone (0.0520) > isopropanol (0.0402) > n-propanol (0.0401) > acetonitrile (0.0298) > ethyl acetate (0.0156). The solubility behaviors of HONB in investigated solvents were analyzed by Hansen solubility parameter (Δδd, Δδp, Δδh, Δδt and Δδ), the consequences showed that solubility order of HONB resulted from the comprehensive function of several solubility parameters. Experimental solubility values were correlated with five thermodynamic models including Nonrandom Two-Liquids (NRTL), Two-Suffix Margules, Universal Quasi-chemical (UNIQUAC), Nonrandom Two-Liquid Segment Activity Coefficient (NRTL-SAC) and Wilson model. Results showed that the smallest average values of average relative deviation (ARD) and root-mean square deviation (104RMSD) were obtained by Wilson model with values of 1.06% and 8.73. Moreover, mixing properties (mixing enthalpy ΔmixH, entropy ΔmixS, Gibbs energy ΔmixG) were evaluated based on measured solubility and equation parameters of Wilson model. The positive values of ΔmixS and negative values of ΔmixG revealed that mixing process of HONB in considered solvents was entropy-driven and spontaneous.

Solubility modelling, solvent effect, preferential solvation and solution thermodynamic of thymine form AH A° in ten mono solvents and two solvent mixtures

The solid-liquid equilibrium solubility of thymine form AH A° at temperature from 283.15 to 323.15 K in methanol, ethanol, 1,4-dioxane, 1-butanol, acetone, 1-propanol, 2-propanol, acetonitrile, N,N-dimethylformamide (DMF), 2-butanone and two mixed solvents (DMF + methanol and DMF + ethanol), solvent effect in mono-solvent systems, preferential solvation in mixed solvent systems, thermodynamic properties and model correlation parameters are reported. The sequence of the mole fraction solubility is DMF > 1,4-dioxane > methanol > ethanol > propanol > -propanol > 1-butanol > acetone > 2-butanone > acetonitrile. Solvent effect had been studied in mono-solvents, and the solubility depended on hydrogen bonding donor (HBD) and hydrogen bonding acceptor (HBA) interactions of solvents with solute and nonspecific dipolarity/polarizability interactions. A dimensionless quantity (δ) was employed to represent the deviation of log x12 values from the mole fraction average, the solute (thymine form AH A°) exhibits preferential solvation, DMF is preferred over methanol or ethanol in the neighborhood of the thymine form AH A°, and the equilibrium constant of the process of solvent exchange (Kps) was used to explain the preferential solvation. The modified Apelblat, Wilson, Jouyban-Acree and CNIBS/R-K models were used as correlation models to correlate the solubility values. The maximum values of relative average deviation (RAD) and root-mean-square deviation (RMSD) for mono-solvent systems were 1.86 × 10−2 and 1.42 × 10−4 and for mixed solvent systems were 3.74 × 10−2 and 3.54 × 10−4. These four models can correlate the solubility of thymine form AH A° in mono-solvents or mixed solvents well. In addition, the thermodynamic properties for the dissolution processes of thymine form AH A° were also calculated based on van't Hoff and Gibbs equations. The results show that the dissolution of thymine form AH A° is the endothermic and entropy-driven process.

Evaluation of the interaction of temperature and light intensity on the growth of Phaeodactylum tricornutum: Kinetic modeling and optimization

In this study, the effects of two highly variable factors, temperature ranging from 10–35 °C and light intensity from 98–1289 μmol m−2s-1, on the specific growth rate, μ, of a diatom, Phaeodactylum tricornutum, at a constant aeration rate of 3000 cm3 min-1 were elucidated. The choice of the adequate kinetic models describing the growth related to temperature and light intensity resulted in rapid determination of optimum growth conditions. Ratkowsky’s square root model and Monod-type model were assessed as the most suitable expressions among the three temperature- and eight light intensity-dependent models, respectively, presenting the highest adjusted R2 and smallest average relative deviation (ARD) values by means of nonlinear least squares method. Also, among the kinetic model approaches utilized to verify the combined effects of temperature and light intensity, the temperature-dependent Ratkowsky model in conjunction with the Monod-type expression with the smallest ARD value (4.19 %) and a high adjusted R2 (0.9775) exhibited the best surface fit. The optimum cultivation temperature and light intensity conditions for the achieving maximum specific growth rate of P. tricornutum were determined as 21 °C and 496 μmol m−2s-1, respectively, by the help of the Central Composite Design (CCD) of the Response Surface Methodology (RSM).

Binary Equilibrium Solubility of Amidinothiourea in Monosolvents: Experimental Determination, Model Correlation, and Solvent Effect Analysis

The equilibrium solubility of amidinothiourea (ATU) in monosolvents, including N-methyl-2-pyrrolidone (NMP), acetone, 1,4-dioxane, acetonitrile, ethyl acetate, toluene, methanol, 1-butanol, 1-propanol, ethanol, 2-propanol, and cyclohexane, was determined by using a isothermal saturation method. The experimental temperature and pressure are 283.15–323.15 K and 101.3 kPa, respectively. The sequence of solubility from high to low is NMP > acetone > 1,4-dioxane > methanol > ethanol > acetonitrile > 1-propanol > ethyl acetate > 2-propanol > 1-butanol > toluene > cyclohexane. Two models (modified Apelblat equation and λh equation) were employed to describe the relationships between solubility of ATU in mole fraction and temperature, and the values of relative average deviations and root-mean-square deviations between the experimental and calculated solubilities were no more than 2.07% and 1.96×10–4, respectively. The appropriateness of the models was evaluated by statistical analysis. Based on the results of st...

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The solubility values of doxifluridine in three mixed solvents of (±)-2-ethyl-1-hexanol + (methanol, ethanol and acetone) ware determined within 278.15–328.15 K under 0.1 MPa using a laser monitoring technique. It can be seen from the solubility profiles that all the solubility of doxifluridine in the mixed solvents increases with the increasing mass fraction of the co-solvent (methanol, ethanol or acetone) and the experimental temperature. The minimum and maximum mole fraction solubility of doxifluridine was found in ethanol + (±)-2-ethyl-1-hexanol (4.981 × 10−5 at w1 = 0.1003, T = 278.15 K) and methanol + (±)-2-ethyl-1-hexanol (1.109 × 10−1 at w1 = 0.9001, T = 328.15 K), respectively. Through the application of Hansen solubility parameters, the solubility order and miscibility of doxifluridine in the three mixed solvents studied in this work was revealed, and the results showed that the dissolution behavior of doxifluridine was not only determined by a single factor, but also the result of the comprehensive action of various solubility parameters. In addition, three semi-empirical models (λh, Modified Apelblat, and MA) and one activity coefficient model (UNIQUAC) were applied to fit the solubility data of doxifluridine. The minimum average values of ARD (average relative deviation) and 104 RMSD (root-mean square deviation) were acquired from Modified Apelblat model, verifying that Modified Apelblat model provides maximum consistency among the four models. Furthermore, Van't Hoff model was used to calculate the apparent thermodynamic parameters (ΔsolG°, ΔsolH°, ΔsolS°) of the dissolution process of doxifluridine. The results demonstrated that the dissolution process of doxifluridine in all the three mixed solvents studied was an entropy-driven endothermic process.

Research and comparison of solid-liquid phase equilibrium and ternary phase diagrams of 1-(3-nitrophenyl)ethanone + 1-(4-nitrophenyl)ethanone in different solvents

The ternary phase equilibrium for 1-(3-nitrophenyl)ethanone and 1-(4-nitrophenyl)ethanone in methanol or n-propanol were determined at 298.15, 308.15 K and 318.15 K under atmospheric pressure in this work. Based on the measured mutual solubility data, the isothermal ternary phase diagrams were constructed. In each ternary phase diagram, there were one co-saturated point, two boundary curves, and three crystalline regions. The crystallization region of 1-(3-nitrophenyl)ethanone was about the same as 1-(4-nitrophenyl)ethanone at all researched temperatures. The NRTL model was used to correlate the solubility of the ternary 1-(3-nitrophenyl)ethanone + 1-(4-nitrophenyl)ethanone + solvents. The correlation results were evaluated by the values of relative average deviation (RAD) and root-mean-square deviation (RMSD), and their values were 4.18 × 10−2 and 3.60 × 10−3, respectively. The calculated results via this model were all acceptable for ternary solid-liquid phase equilibrium. The ternary phase diagram obtained will play an important part in separating the mixture of 1-(3-nitrophenyl)ethanone and 1-(4-nitrophenyl)ethanone.

Solubility Measurement and Correlation of Probenecid in 12 Pure Organic Solvents and Thermodynamic Properties of Mixing of Solutions

The solubility data of probenecid in 12 different organic solvents including methanol, methyl acetate, ethanol, ethyl acetate, n-propanol, n-butanol, butyl acetate, n-pentanol, isopropanol, isobutanol, acetone, and methyl tert-butyl ether was measured using the gravimetric method over the temperatures range from 283.15 to 323.15 K at 0.1 MPa. The acetone had much higher solubility to probenecid than to other solvents. Three models, including the modified Apelblat equation, the van’t Hoff model, and the nonrandom two-liquid (NRTL) model, were applied to correlate the measured solubility data. The correlation results were evaluated by the average relative deviation (ARD). All of the ARD values were less than 4.522%, which indicated that the three models have a satisfactory correlation. The thermodynamic properties of mixing of probenecid in 12 pure organic solvents including the enthalpy of mixing, Gibbs energy of mixing, and entropy of mixing were calculated by the NRTL model using the correlation results.

Construction and evaluation of ternary solid-liquid phase diagram of pyraclostrobin (form IV) and its intermediate in ethanol and N,N-dimethylformamide

Abstract In order to improve the purity of target product and reduce the cost of industrial production, the phase diagrams of pyraclostrobin and its intermediate (pheny N-methoxy-N- (2- ((N′-pyrazinyl) pyrazolyl-3′-oxymethyl) -phenyl) carbamate) in binary and ternary systems was studied. In each ternary phase diagram, there were three crystallization regions (pure pyraclostrobin intermediate, pure pyraclostrobin, and mixture of pyraclostrobin and its intermediate), two co-saturated curves, and one co-saturated point. The crystallization region of pyraclostrobin intermediate was larger than that of pyraclostrobin in ethanol and N, N-dimethylformamide (DMF) at three temperatures. In order to extend application of the obtained binary and ternary systems, the NRTL model and Wilson model were used to describing the solubility behaviour of pyraclostrobin and its intermediate in binary and ternary systems, the value of root-mean-square deviation (RMSD) was no more 9.01 × 10−3, the value of relative average deviation (RAD) was a little large, and no more than 5.84%. The calculated results via two models were all acceptable for the binary and ternary solid-liquid phase equilibrium. Ethanol and DMF in different temperature can be applied to separate the mixture of pyraclostrobin and its intermediate.

Solubility and Dissolution Thermodynamics of Cefmetazole Acid in Four Neat Solvents and Preferential Solvation in Co-Solvent Mixtures of (Methanol, Ethanol or Isopropanol) + Water

The solubilities of cefmetazole acid in methanol, ethanol, isopropanol and water were determined experimentally by using the saturation shake-flask method within the temperature range from (278.15 to 303.15) K under pressure p = 101.1 kPa. At a fixed temperature, the cefmetazole acid solubility falls in the order methanol > ethanol > isopropanol > water. The apparent dissolution enthalpy, dissolution entropy and Gibbs energy change were calculated. The acquired solubilities were correlated with Apelblat’s equation. The largest value of relative average deviation for mole fraction solubility was 0.45 × 10−2, and of root-mean-square deviation, 0.747 × 10−5. The type and extent and direction of solute–solvent interactions were identified using the concept of Linear Solvation Energy Relationship. In addition, the preferential solvation parameters (δx1,3) of cefmetazole acid in co-solvent mixtures of methanol (1) + water (2), ethanol (1) + water (2) and isopropanol (1) + water (2) were derived via the inverse Kirkwood–Buff integrals method. At 298.15 K, the magnitude of preferential solvation of cefmetazole acid by the co-solvent is highest in methanol mixtures, followed by ethanol mixtures, and finally by isopropanol mixtures.