Dissolution Thermodynamic Properties Research Articles

Solubility and thermodynamic properties of L-Pyroglutamic acid in pure and binary solvents

The solubility of L-Pyroglutamic acid in H2O, methanol, ethanol, n-propanol, isopropanol and four binary solvent systems (H2O + methanol/ethanol/n-propanol/isopropanol) from (293.15–344.35) K was experimentally determined under atmospheric pressure by using isothermal saturation method. The results indicated that the solubility of L-Pyroglutamic acid in all the tested pure and binary solvent systems monotonously increased with increasing of the temperature at the measurable range. The solubility order of L-Pyroglutamic acid in pure solvents was ranked as: H2O > methanol > ethanol > n-propanol ≈ isopropanol. Part solubility of L-Pyroglutamic acid in the mixture of H2O + methanol/ethanol/n-propanol/isopropanol became larger than that in both pure solvents. Besides, Ideal model, the Apelblat model, λh model, Wilson model and NRTL model were used to correlate the experimental solubility data of L-Pyroglutamic acid in five pure solvent systems and the solubility in binary solvent systems were correlated by Ideal model, the Apelblat model, λh model, Wilson model, NRTL model, the Apelblat-Jouyban-Acree (A-JA) model and the Van't Hoff- Jouyban-Acree (Van't-JA) model. All of them gave satisfactory correlations. Finally, the mixing and dissolution thermodynamic properties, including Gibbs energy, entropy and enthalpy of L-Pyroglutamic acid in all tested solvents were calculated by the Wilson equation and the solubility data.

Solubility measurement, solubility behavior analysis and thermodynamic modelling of melatonin in twelve pure solvents from 278.15 K to 323.15 K

Solubility of melatonin in twelve mono-solvents including seven alcohols {methanol (MT), ethanol (ET), n-propanol (n-PrA), n-butanol (n-BT), i-butanol (i-BT), n-pentanol (n-PT) and n-hexanol (n-HeA)} and five esters {methyl acetate (MeAC), ethyl acetate (EtAC), n-propyl acetate (n-PrAC), n-butyl acetate (n-BtAC) and n-pentyl acetate (n-PtAC)} was determined by laser monitoring approach from 278.15 K to 323.15 K under 0.1 MPa. The experimental results indicate that the mole solubility of melatonin shows a positive relation with temperature variation. The solubility of melatonin in the twelve pure solvents at 298.15 K has order: MT (0.03570) > ET (0.02536) > n-PrA (0.01965) > n-BT (0.01524) > n-PT (0.01450) > i-BT (0.01267) > n-HeA (0.01136) > MeAC (0.008498) > EtAC (0.006587) > n-PrAC (0.004280) > n-BtAC (0.003410) > n-PtAC (0.02990). Moreover, the miscibility behavior of melatonin was further analyzed by the Hansen solubility parameter (HSP). The solvent effect of melatonin in tested pure solvents was investigated by using the KAT-LSER model. The four thermodynamic models including two-Suffix Margules, NRTL, NRTL-SAC and UNIQUAC models were applied to correlate the experimental solubility data of melatonin. Furthermore, the dissolution thermodynamic properties including the apparent standard dissolution enthalpy (ΔdisHo), the apparent standard dissolution entropy (ΔdisSo) and the apparent standard Gibbs energy change (ΔdisGo) of melatonin in investigated solvents were calculated by van't Hoff equation.

Measurement and correlation of coumarin solubility in aqueous solution of acidic deep eutectic solvents based on choline chloride

The solubility of coumarin in three aqueous solutions of acidic deep eutectic solvents (DESs) based on choline chloride (ChCl) as hydrogen bond acceptor (HBA) with some carboxilic acids (propionic acid, lactic acid and acetic acid) as hydrogen bond donors (HBD) have been measured using the shake flask method at T = (298.15 to 313.15) K. According to obtained results, the solubility of coumarin increases with increasing the weight fraction of ChCl/propionic acid more than 100-fold. The experimental solubility data were correlated by electrolyte Nonrandom Two-Liquid (e-NRTL),Wilson and UNIQUAC activity coefficient models. Then, the dissolution thermodynamic properties, enthalpy, Gibbs free energy and entropy were calculated based on Gibbs and van't Hoff equations to investigate the solvation behavior of coumarin in the aqueous DES solutions.

Solubility Measurements and Thermodynamic Properties of Sorbic Acid in Binary Solvent Mixtures of (Ethanol, 1-Propanol or 2-Propanol + Water) from 283.15 to 323.15 K

The solubility data of sorbic acid in binary systems of (ethanol + water), (1-propanol + water) and (2-propanol + water) were measured from 283.15 to 323.15 K using the static equilibrium method under atmospheric pressure. It was found that the solubility of sorbic acid in the three binary solvent systems increased with increasing temperature as well as increasing initial mole fraction of organic solvent in these systems. The van’t Hoff–Jouyban–Acree model, the modified Apelblat–Jouyban–Acree model and the CNIBS/R-K model were proposed for correlating the experimental solubility values in various solution systems. Furthermore, the dissolution thermodynamic properties of Gibbs energy change (ΔsolGo), molar enthalpy change (ΔsolHo) and molar entropy change (ΔsolSo) were calculated from the experimental solubility data, using the van’t Hoff equation. The positive values of ΔsolGo, ΔsolHo and ΔsolSo indicate that these dissolution processes of sorbic acid in the solvents studied were all endothermic and entropically favorable. In addition, the change of dissolution enthalpy was the main contributor to the positive value of the molar Gibbs energy of the dissolution process. The experimental solubility and the models used in this work would be conducive to purifying sorbic acid from its crude mixtures.

Solubility and dissolution thermodynamic properties of L-carnosine in binary solvent mixtures

Thermodynamic data are the basis for design of crystallization process and control of crystal morphology and polymorph. In this work, solubility data of L-carnosine in different binary solvent mixtures, including water + (methanol, isopropanol or acetone), were determined in temperatures ranging from 288.05 K to 323.15 K by static method under atmospheric pressure. It was found that the solubility data of L-carnosine decrease apparently with the increasing of the mole fraction of organic solvent in binary solvent mixtures and increase with the rising of temperature. In addition, the experimental solubility data were correlated and analyzed by the modified Apelblat equation, the NRTL model and the Jouyban–Acree model to extend the applicability of the solubility data. Finally, the standard dissolution thermodynamic properties, including Gibbs energy, entropy and enthalpy were calculated and discussed based on the experimental solubility data and Van’t Hoff equation.

Solubility and thermodynamic mixing and dissolution properties of empagliflozin in pure and binary solvent systems

Abstract In this work, the solubility data of empagliflozin in nine pure solvents and one binary solvent were measured by dynamic method at the temperature ranging from 278.15 K to 313.15 K. The results showed that the solubility data of empagliflozin in all measured solvents increased with the increasing of temperature. Besides, the NRTL model, the modified Apelblat equation and the λh equation were used to correlate the experimental solubility data of empagliflozin in nine pure solvent systems and the solubility in binary solvent systems was correlated by the NRTL model, the CNIBS/R-K model and the Jouyban-Acree model. The computational results showed that the modified Apelblat equation can give better correlation results for nine pure solvent systems while the CNIBS/R-K model is more accurate for binary solvents system. Finally, the mixing and dissolution thermodynamic properties, including Gibbs energy, entropy and enthalpy of empagliflozin in all tested solvents were calculated by the NRTL model and the solubility data.

Solubility determination, various solubility parameters and solution thermodynamics of sunitinib malate in some cosolvents, water and various (Transcutol + water) mixtures

Abstract Temperature-dependent solubility data and other physicochemical parameters of sunitinib malate (SM) are scarce in literature. Therefore, in this research, the solubility, various solubility parameters and dissolution thermodynamic properties of SM in six cosolvents {i.e., ethanol, isopropanol (IPA), ethylene glycol (EG), propylene glycol (PG), polyethylene glycol-400 (PEG-400) and Transcutol-HP (THP)}, water and various THP + water mixtures at “T = 298.2 K to 318.2 K” and “p = 0.1 MPa” were determined. The experimental solubilities of SM were validated using five different computational models such as “van't Hoff, Apelblat, Yalkowsly-Roseman, Jouyban-Acree and van't Hoff-Jouyban-Acree models”. All the studied models performed good correlation and validation. Various solubility parameters of SM, cosolvents, water and different THP + water mixtures were estimated to select the best solvent for SM solubility/miscibility. The mole fraction solubilities of SM were obtained maximum in pure THP (1.87 × 10−2) followed by PEG-400, IPA, ethanol, PG, EG and water (1.05 × 10−5) at “T = 318.2 K”. The similar trends of solubility were also found at “T = 298.2, 303.2, 308.2 and 313.2 K”. Most of the solubility parameters of SM were found to very close with pure THP. Apparent thermodynamic analysis suggested an endothermic and entropy-driven dissolution of SM in six different cosolvents, water and all THP + water mixtures. The maximum interactions at molecular level were found in SM-THP in comparison with other SM-cosolvents and SM-water combinations. Based on these results, THP has been chosen as the best cosolvent for solubility/miscibility of SM.

Solubility and dissolution thermodynamic properties of Mequindox in binary solvent mixtures

The solubility of Mequindox(MEQ) in two kinds of binary mixtures(acetone+isopropanol; N-propanol+N-butanol) with different ratio was determined by shake flask method through UV–Vis spectrophotometer over the temperature from 293.15 to 323.15 K at atmospheric pressure(p = .1 MPa). The results showed that the solubility of mequindox in binary solvent mixtures was increased with temperature raised in the investigated temperature range. In the binary-solvent of acetone and isopropanol, the data was increased as the mole fraction of acetone increased. However, the solubility of MEQ was not significantly changed in the mixed solvents of N-propanol and N-butanol with different ratio. Furthermore, thermodynamic models including the modified Apelblat equation, λh equation, GSM equation and the Jouyban-Acree model were used to correlate the experimental data. In addition, thermodynamic properties, enthalpy (△H0sol), entropy (△S0sol) and Gibbs free energy (△G0sol), were calculated and analyzed in the dissolution process. This study provides a certain theoretical basis for the isolation purification and pharmaceutical formulation design of MEQ.

The dissolution behaviour and thermodynamic properties calculation of praziquantel in pure and mixed organic solvents

The purpose is to study the dissolution behaviour for praziquantel in different solvent. The dissolution capacity within the temperature range from 273.15 K to 313.15 K was researched by using the isothermal equilibrium method and evaluated with the modified Apelblat equation, λh equation and Jouyban-Acree model. In pure solvents, the largest values were found in N-methyl pyrrolidone (NMP, 8.106 × 10−2 in mole fraction) at 313.15 K, and followed by cyclohexanone (5.964 × 10−2), toluene (3.842 × 10−2), acetonitrile (3.519 × 10−2), acetone (3.001 × 10−2), ethyl acetate (2.896 × 10−2), n-octanol (2.715 × 10−2), isopropanol (1.882 × 10−2) and n-hexane (4.379 × 10−2). While in mixtures of (NMP + isopropanol), the solubility capacity increased monotonically with the increase of temperature and NMP mass fraction. KAT-LSER method was applied to analyse the effect of solute–solvent intermolecular interactions on the solubility in pure solvents. More importantly, the selection of appropriate solvents for praziquantel dissolution is important to its application. Moreover, the effect of the solute–solvent intermolecular interactions on the solubility in pure and mixed solvents was discussed as well. In the following, the analysis of apparent thermodynamic analysis indicates that the dissolution is an endothermic, spontaneous and entropy driven process.

Solution thermodynamics of ceftezole in seven pure solvents and two binary solvent mixtures

In this work, solubility data of ceftezole in seven pure solvents and two binary solvent systems were experimentally measured via a static gravimetric method in the temperature range from 278.15 K to 313.15 K under atmospheric pressure. The results indicated that the solubility of ceftezole in all the selected pure and binary solvent systems increased with the rising of temperature. It was also found that the solubility order of ceftezole in the seven mono-solvents was generally ranked as: water < methanol < ethanol < isopropanol < acetonitrile < ethyl acetate < acetone. The Apelblat model and the NRTL model were used to correlate the experimental solubility data of ceftezole in pure solvents, and the modified Apelblat equation, the CNIBS/R-K model and the combined version of the Jouyban–Acree were applied for binary solvents. The calculation results agreed fairly well with the experimental data. Finally, the mixing and dissolution thermodynamic properties of ceftezole in all the tested solvents were calculated based on the NRTL model and the experimental solubility data.

Cosolvent action of promethazine hydrochloride in (ethyl acetate + alcohols) and thermodynamic property analysis

This study presents the solubility profiles of promethazine hydrochloride in pure and mixed solvents. The effects of temperature and composition of mixed solvents on solubility were investigated. Maximum solubility value was obtained in n-propanol in pure solvents, and in ethyl acetate, it is the lowest. While in two mixtures of ethyl acetate (1 − w) + ethanol (w, mass fraction) and ethyl acetate (1 − w) + isopropanol (w), the values increased monotonically with the increasing temperature, and increased with increasing co-solvent (alcohols) mass fraction (w) to a maximum value at w = 0.4 and then decreased. The interaction between promethazine hydrochloride molecule and solvent molecules was discussed. The function of temperature and solvent composition in pure and binary mixed solvents was evaluated by some thermodynamic models. The dissolution thermodynamic properties, including enthalpy, entropy and Gibbs energy of promethazine hydrochloride in the dissolution process were evaluated using the van't Hoff equation. The results indicate that in all selected solvents the dissolution behavior were endothermic and entropy-driven.

Solution thermodynamic properties of flurbiprofen in twelve solvents from 283.15 to 323.15 K

In this work, solution thermodynamic properties including solubility, mixing thermodynamic properties and dissolution thermodynamic properties are investigated in detail. Gravimetric method was utilized for measuring the solubility data of flurbiprofen in twelve pure solvents including n-propanol, isopropanol, n-butanol, isobutanol, isopentanol, isopropyl acetate, methyl tert-butyl ether, isopropyl ether, acetonitrile, n-octane, n-heptane and n-hexane over the temperatures range from 283.15 to 323.15 K under atmospheric pressure. The results indicated that the solubility of flurbiprofen increased with the increasing temperature. Furthermore, the experimental solubility data were correlated by the modified Apelblat equation, λh equation, Wilson model and NRTL model. And the modified Apelblat equation can give better correlation results with lower values of ARD%. Moreover, mixing and dissolution thermodynamic properties of flurbiprofen in different solvents were calculated according to the experimental data and the NRTL model.

Solid-liquid equilibrium and thermodynamic properties of dipyridamole form II in pure solvents and mixture of (N-methyl pyrrolidone + isopropanol)

The solid–liquid equilibria of a poorly soluble drug namely dipyridamole were assayed to determine solubility in pure and binary mixtures between 273.15 K and 313.15 K under atmospheric pressure. The solubility profiles of dipyridamole in pure and mixed solvents were evaluated by some thermodynamic models. The maximum solubility in mole fraction was obtained in pure N-methyl pyrrolidone (NMP) in all tested solvents. In mixtures of (NMP + isopropanol), the values increased monotonically with the increasing temperature and mass fraction of NMP. The Kamlet, Abboud and Taft Linear Solvation Energy Relationship (KAT-LSER) model was applied to analyze the effect of the solute–solvent intermolecular interactions on the solubility. The results of dissolution thermodynamic properties indicate that the dissolution behavior were endothermic and entropy-driven in all tested solvents. The experimental solubility data and mathematically correlated equations of dipyridamole estimated in this work may be useful for studies on the crystallization process of the final step of dipyridamole synthesis, for the purification dipyridamole of pharmaceutical applications.

Dissolution behavior and thermodynamic properties of apixaban in pure and mixed solvents

The solubility profile of apixaban in pure and mixed solvents within the temperature range from (288.15 to 328.15) K under atmosphere pressure (101.3 kPa) was studied and evaluated by some thermodynamics models. The solid state of apixaban in equilibrated form was characterized using powder X-ray diffraction (PXRD) technique. The maximum mole solubility in pure solvents was obtained in 1, 4-dioxane (3.648 × 10−3) at 328.15 K, and followed by methanol (1.967 × 10−3), acetone (7.885 × 10−4),ethanol (6.049 × 10−4), isopropanol (3.806 × 10−4), ethyl acetate (2.266 × 10−4), n-hexane (1.883 × 10−4), water (3.989 × 10−5). The solubility was quite small. Therefore, the solubility profile of apixaban in mixtures of (1, 4-dioxane + water) was further studied. Moreover, it increased at first and then decreased with the increasing mass fraction of 1, 4-dioxane. Moreover, the extended Hildebrand solubility approach (EHSA) was applied to evaluate the co-solvency phenomenon in mixed solvent at 298.15 K. In the following, the analysis of apparent thermodynamic properties indicates that the dissolution process in all selected solvents is an endothermic and entropy driven process.

Thermodynamic analysis and molecular dynamic simulation of the solubility of saccharin in three binary solvent mixtures

The equilibrium solubility of saccharin in binary solvent mixtures of methanol + acetonitrile, ethanol + acetonitrile, and isopropanol + acetonitrile was determined by using a gravimetric method within the temperature range from 293.15 K to 323.15 K at atmospheric pressure. Intriguingly, the solubility exhibits a maximum value at around 0.5 mol fraction of alcohols in all the solvent systems regardless of temperature. The cooperation effect between the solute-solvent interaction and solvent-solvent interaction was revealed by the molecular simulation study to give the explanation for the dissolving ability of saccharin in solvent mixtures. Moreover, the experimental solubility data was correlated by the Jouyban-Acree model, van’t Hoff-Jouyban-Acree model and Apelblat-Jouyban-Acree model, and the Jouyban-Acree model provides the best fitting performance. Furthermore, the dissolution thermodynamic properties of apparent standard dissolution enthalpy, Gibbs free energy and entropy were computed, and the results indicate that the dissolution process of saccharin is non-spontaneous, endothermic and entropy-driven.

Stability, solubility and thermodynamic properties of dimorphs of furosemide-4,4′-bipyridine cocrystals in organic solvents

In this work, pure form I and form II of furosemide-4,4′-bipyridine (FS-4BPY) 2:1 cocrystals were prepared. Both polymorphs were characterized by optical microscopy, powder X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, and Fourier transform infrared spectroscopy. The relative stability of the two forms was estimated from their solubility data in 2-propanol by the gravimetric method. Moreover, the thermodynamically stable form with lower solubility, form II, was further investigated in different pure and binary solvents from 293.15 K to 333.15 K under atmospheric pressure. In pure solvent system, the solubilities of forms II cocrystals increase with rising temperature and follow the order of acetone > ethanol > 1-propanol ≈ 1-butanol > 2-propanol > acetonitrile. In 2-propanol–water binary solvent system, the co-solvency phenomenon was observed and the maximum solubility of form II is higher than that in pure solvents. The experimental solubility data were correlated by the modified Apelblat model, the CNIBS/R–K model, the Jouyban–Acree model and the NRTL model, and all models give satisfactory correlations. Finally, the apparent dissolution thermodynamic properties, including the dissolution Gibbs energy, the dissolution enthalpy and the dissolution entropy, were calculated based on the NRTL model. The results indicate that the dissolution processes of form I and form II of FS-4BPY cocrystals in selected solvents are all spontaneous, endothermic, and entropy-driven.

Solubility and thermodynamic properties of azlocillin in pure and binary solvent systems

The solubility data of azlocillin (ALPC) in nine mono-solvents (methanol, ethanol, isopropanol, methyl acetate, ethyl acetate, isopropyl acetate, acetone, acetonitrile, tetrahydrofuran) and two different binary solvent systems (methanol + isopropanol, ethanol + isopropanol), under atmospheric pressure, were experimentally measured via a static gravimetric method in the temperature range from 278.15 K to 323.15 K. According to the experimental results, it could be found that the solubility of ALPC in all the tested pure and binary solvent systems increased with the rise of temperature at the measurable ranges. The solubility order of ALPC in the nine mono-solvents is generally ranked as: (ethanol or tetrahydrofuran) > acetone > (methanol or acetonitrile) > methyl acetate > ethyl acetate > isopropanol > isopropyl acetate. The solubility data of ALPC in both binary solvent systems increase with the increasing of mole fraction of methanol or ethanol. The modified Apelblat equation, λh equation, and NRTL model were applied to correlate the experimental solubility data of ALPC in pure and mixed solvent systems while the CNIBS/R-K model was also used for the mixed solvent systems. Finally, the mixing and dissolution thermodynamic properties of ALPC in the studied systems were calculated by the NRTL model and were analyzed. It was found that the mixing and dissolution processes of ALPC in the tested systems were spontaneous, endothermic and entropy-driven.

Solubility determination and modelling of benzamide in organic solvents at temperatures from 283.15 K and 323.15 K, and ternary phase diagrams of benzamide-benzoic acid cocrystals in ethanol at 298.15 K

In this paper, several common solvents including butyl acetate, methyl acetate, ethyl acetate, acetonitrile, 1-butanol, isobutanol, isopropanol, ethanol, 1-propanol, methanol, acetone, and water, were selected as solubility solvents for benzamide. The solubility of benzamide in all solvents increases with the increase of temperature from 283.15 K to 323.15 K, and generally depends on solvents in the following order: methanol > acetone > ethanol > 1-propanol > 1-butanol > isopropanol > isobutanol > methyl acetate > ethyl acetate > butyl acetate > acetonitrile > water. Solubility data in all solvents were well correlated with the temperature by using the NRTL, Wilson and modified Apelblat models. Furthermore, the dissolution thermodynamic properties, which include dissolution Gibbs energy, dissolution entropy and dissolution enthalpy, were also calculated. Based on the above results, ethanol was chosen as the solvent for preparing benzamide cocrystal with benzoic acid. The ternary phase diagram of benzamide-benzoic acid cocrystals in ethanol was constructed, and one stable cocrystal with a stoichiometry of 1:1 was determined and characterized.

Solution thermodynamics of tris-(2,4-ditert-butylphenyl)-phosphite in a series of pure solvents

In this work, to help the development and design of separation and purification processes for tris-(2,4-ditert-butylphenyl)-phosphite which is an antioxidant of plastic processing, its solution thermodynamics was investigated. Using a static gravimetric method, solubilities of tris-(2,4-ditert-butylphenyl)-phosphite in twelve pure solvents (including acetone, ethyl acetate, methyl acetate, ethyl formate, isopropyl acetate, butyl acetate, n-hexane, n-heptane, n-octane, isooctane, propyl acetate and ethyl butyrate) were measured at temperatures varying from 278.15 K to 323.15 K. It was found that, in all investigated solvents, the solubility data of tris-(2,4-ditert-butylphenyl)-phosphite increased with the increasing of temperature over the entire investigated temperature range. The modified Apelblat equation, the λh equation and the NRTL model were employed to correlate the solubility data. The computed data showed that the modified Apelblat equation correlated the solubility data better. Moreover, the mixing and dissolution thermodynamic properties of tris-(2,4-ditert-butylphenyl)-phosphite in various pure solvents were also calculated according to the NRTL model and the experimental solubility data.

Solid-liquid equilibrium and thermodynamic properties of N,2,3-trimethyl-2-isopropylbutamide in seventeen mono solvents from T = (273.15 to 319.15) K

The objective of this work is to obtain the solubility, correlation equation parameters and dissolution thermodynamic properties for N,2,3-trimethyl-2-isopropylbutamide in different solvents, which is essential for its purification and further crystal morphology optimization. By using a static gravimetric method, the solubility of N,2,3-trimethyl-2-isopropylbutamide in seventeen pure solvents (methanol, ethanol, acetone, ethyl acetate, dichloromethane, n-hexane, isooctane, acetonitrile, n-propanol, n-butanol, cyclohexane, isopropanol, n-octanol, cyclohexanone, toluene, 1,2-dichlorobenzene and n-pentanol) was measured over temperature range from 273.15 K to 319.15 K under atmosphere pressure. The results indicated that the mole fraction solubility increased with the rising temperature in all solvents. Besides, the experimental solubility was correlated with the modified Apelblat equation, van't Hoff equation, λh equation, non-random two-liquid (NRTL) equation and Wilson equation. Good agreements were found between the experimental data and above models fitted values, especially the modified Apelblat equation provided the best fitting results. Finally, the dissolution thermodynamic parameters, Gibbs energy (△disG), molar enthalpy (△disH) and molar entropy (△disS) were calculated based on the experimental data and the Wilson model.