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The growing demand for more sustainable routes and processes in the mixture separation and purification industry has generated a need to search for innovations, with new solvent alternatives being a possible solution. In this context, a new class of green solvents, known as deep eutectic solvents (DESs), has been gaining prominence in recent years in both academic and industrial spheres. These solvents, when compared to ionic liquids (ILs), are more environmentally friendly, less toxic, low-cost, and easier to synthesize. In addition, they have significantly lower melting points than their precursors, offering a promising option for various applications in this industrial sector. Understanding and studying the thermodynamic behavior of systems composed of these substances in purification and separation processes, such as liquid–liquid extraction and azeotropic distillation, is extremely important. This work aimed to study the phase behavior of liquid–liquid equilibrium (LLE) and vapor–liquid equilibrium (VLE) of water + 1-butanol + DES (choline chloride + glycerol) systems with a molar ratio of 1:2. Experimental LLE data, obtained at 298.15 K and 101.3 kPa, and VLE data, obtained at 101.3 kPa and in the temperature range of 364.05 K–373.85 K, were submitted to the thermodynamic quality/consistency test, proposed by Marcilla et al. and Wisniak, and subsequently modeled using the gamma–gamma approach for the LLE and gamma–phi for the VLE. The non-random two-liquid (NRTL) model was used to calculate the activity coefficient. The results are presented for the VLE in a temperature–composition phase diagram (triangular prism) and triangular phase diagrams showing the binodal curve and tie lines (LLE). The separation and distribution coefficients of LLE were determined to evaluate the extractive potential of the DES. For the VLE, the values of the relative volatility of the system were calculated, considering the entrainer free-basis, to evaluate the presence or absence of azeotropes in the range of collected points. From these data, it was possible to compare DES with ILs as extracting agents, using data from previous studies carried out by the research group. Therefore, the results indicate that the NRTL model is efficient at correlating the fluid behavior of both equilibria. Thus, this study serves as a basis for future studies related to the understanding and design of separation processes. [ABSTRACT FROM AUTHOR]

The esterification of 1-methoxy-2-propanol (PM) and acetic acid (AA) is an important reaction for the production of 1-methoxy-2-propyl acetate (PMA). Herein, we used the macroporous ion-exchange resin Amberlyst-35 as a catalyst to explore the effects of reaction conditions on the reaction rate and equilibrium yield of PMA. Under the optimized conditions of a reaction temperature of 353 K, using the initial reactant PM/AA with a molar ratio of 1:3, and a catalyst loading of 10 wt%, the PMA equilibrium yield reached 78%, which is the highest equilibrium yield so far. The reaction equilibrium constants and activity coefficients were estimated to obtain reaction thermodynamic properties, indicating the exothermicity of the reaction. Furthermore, pseudo-homogeneous (PH), Eley–Rideal (ER), and Langmuir–Hinshelwood–Hougen–Watson (LHHW) kinetic models were fitted based on experimental reaction kinetic data. The results demonstrate that the LHHW model is the most consistent with experimental data, indicating a surface reaction-controlled process and exhibiting an apparent activation energy of 62.0 ± 0.2 kJ/mol. This work represents a valuable example of calculating reaction thermodynamics and kinetics, which are particularly essential for promising industrial reactor designs. [ABSTRACT FROM AUTHOR]

Citrus medica L. is a traditional citrus fruit that is rich in bioactive compounds and has the potential to be used as a natural source of food additives. This study aims to evaluate the antioxidant capacity and characterize the phenolic compounds present in the peels (including flavedo and albedo), pulp, and seeds of citron. The results showed that, compared to the other parts, the pulp had a substantially higher Antioxidant Activity Coefficient (AAC) of 168.2. The albedo and the seeds had significantly lower AAC values, while the green and yellow flavedo showed noteworthy results. O-coumaric acid was the predominant phenolic acid in all of the citron fractions; it was found in the highest concentration in albedo (37.54 µg/g FW). Flavanones and flavanols were the primary flavonoids in the pulp, peel, and seeds, with total flavonoid concentration ranging from ~9 µg/g FW in seeds to 508 µg/g FW in the pulp. This research offers significant insights into the antioxidant properties of this ancient fruit, emphasizing its potential applications as a natural source of antioxidants to be used in different applications. [ABSTRACT FROM AUTHOR]

Solubility is one of the most important physicochemical properties due to its involvement in physiological (bioavailability), industrial (design) and environmental (biotoxicity) processes, and in this regard, cosolvency is one of the best strategies to increase the solubility of poorly soluble drugs in aqueous systems. Thus, the aim of this research is to thermodynamically evaluate the dissolution process of triclocarban (TCC) in cosolvent mixtures of {N-methyl-2-pyrrolidone (NMP) + water (W)} at seven temperatures (288.15, 293.15, 298.15, 303.15, 308.15, 313.15 and 318.15 K). Solubility is determined by UV/vis spectrophotometry using the flask-shaking method. The dissolution process of the TCC is endothermic and strongly dependent on the cosolvent composition, achieving the minimum solubility in pure water and the maximum solubility in NMP. The activity coefficient decreases from pure water to NMP, reaching values less than one, demonstrating the excellent positive cosolvent effect of NMP, which is corroborated by the negative values of the Gibbs energy of transfer. In general terms, the dissolution process is endothermic, and the increase in TCC solubility may be due to the affinity of TCC with NMP, in addition to the water de-structuring capacity of NMP generating a higher number of free water molecules. [ABSTRACT FROM AUTHOR]

The ionic association constants of sodium with carbonate ion ( K 1 C ′ ) and acidic carbonate ions ( K 2 C ′ ) were measured in NaCl-NaHCO3-H2O ternary systems to determine the distribution of sodium among the chemical species present in the growth medium of Chlorella homosphaera 424 algae. The mean activity coefficients of sodium chloride (in pure sodium chloride and in a mixture of electrolytes) were determined experimentally using two electrochemical cells, namely Ag, AgCl| KCl (3 M)|| NH4NO3 (1 M)| NaCl ( m NaCl )| Na+-ISE and Ag, AgCl|KCl (3 M)|| NH4NO3 (1 M)| NaCl ( m NaCl )| Cl−-ISE. The studies carried out show that the values of the association constants of K 1 C ′ and K 2 C ′ do not depend on the composition of the medium, but only on the effective ionic strength. The experimentally obtained γ NaCl 0 values in the binary system are comparable to the mean activity coefficients values for NaCl, calculated using data from the literature, with −0.9 to 0.1% relative standard deviation. The obtained results show that the experimentally determined mean activity coefficient in the ternary system, γ NaCl , is smaller than γ NaCl 0 in the binary system over the entire field of ionic strengths studied. The ternary system NaCl-NaHCO3-H2O obeys Harned's rule. [ABSTRACT FROM AUTHOR]

The suggestion that the paper by Naef and Acree is the first one with the capability to treat "any molecule under the sun" is simply totally incorrect. In Ref. [[7]] (Neaf and Acree), reference to GC methods are only the previous publications by Naef and Acree. 10.3390/molecules25051147 7 Naef R., Acree W.E. Jr. Calculation of the Vapour Pressure of Organic Molecules by Means of a Group-Additivity Method and their Resultant Gibbs Free Energy and Entropy of Vaporization at 298.15 K. References 1 Naef R., Acree W.E. Jr. Revision and Extension of a Generally Applicable Group-Additivity Method for the Calculation of the Standard Heat of Combustion and Formation of Organic Molecules. [Extracted from the article]

The vapor–liquid equilibrium of the fluorobenzene–polystyrene binary polymer solution at 303.15 K was measured using a static pressure device. The vapor–liquid equilibrium of the fluorobenzene–n-octane–polystyrene ternary solution in a partial concentration range under normal pressure was determined using an improved Othmer equilibrium still, in which the octane concentration was low. Three activity coefficient models, poly-NRTL, UNIQUAC, and M-UNIQUAC-LBY, were utilized to correlate the experimental data of binary and ternary solutions, and the component activities of the fluorobenzene–n-octane–polystyrene solution at 303.15 K were predicted. A mathematical model based on the Stefan flow was developed to simulate the evaporation process of composite spherical droplets. The activity predicted by the activity coefficient model was used for numerical simulations, and compared with simulations using the activity following Raoult's law. The comparative analysis revealed that simulations based on Raoult's law and activity coefficient models yielded similar results when the mass fraction of fluorobenzene exceeded 0.6. However, in the later stages of evaporation, the calculations based on Raoult's law predicted a 10% shorter drying time for fluorobenzene. The activity coefficient models provided a better approximation and exhibited similar droplet diameter shrinking behaviors to the actual evaporation process. [ABSTRACT FROM AUTHOR]

Ibuprofen (Ibf) is a biologically active drug (BADs) and an emerging contaminant of concern (CECs) in aqueous streams. Due to its adverse effects upon aquatic organisms and humans, the removal and recovery of Ibf are essential. Usually, conventional solvents are employed for the separation and recovery of ibuprofen. Due to environmental limitations, alternative green extracting agents need to be explored. Ionic liquids (ILs), emerging and greener alternatives, can also serve this purpose. It is essential to explore ILs that are effective for recovering ibuprofen, among millions of ILs. The conductor-like screening model for real solvents (COSMO-RS) is an efficient tool that can be used to screen ILs specifically for ibuprofen extraction. The main objective of this work was to identify the best IL for the extraction of ibuprofen. A total of 152 different cation–anion combinations consisting of eight aromatic and non-aromatic cations and nineteen anions were screened. The evaluation was based upon activity coefficients, capacity, and selectivity values. Furthermore, the effect of alkyl chain length was studied. The results suggest that quaternary ammonium (cation) and sulfate (anion) have better extraction ability for ibuprofen than the other combinations tested. An ionic liquid-based green emulsion liquid membrane (ILGELM) was developed using the selected ionic liquid as the extractant, sunflower oil as the diluent, Span 80 as the surfactant, and NaOH as the stripping agent. Experimental verification was carried out using the ILGELM. The experimental results indicated that the predicted COSMO-RS and the experimental results were in good agreement. The proposed IL-based GELM is highly effective for the removal and recovery of ibuprofen. [ABSTRACT FROM AUTHOR]

Polyelectrolyte has wide applications in biomedicine, agriculture and soft robotics. However, it is among one of the least understood physical systems because of the complex interplay of electrostatics and polymer nature. In this review, a comprehensive description is presented on experimental and theoretical studies of the activity coefficient, one of the most important thermodynamic properties of polyelectrolyte. Experimental methods to measure the activity coefficient were introduced, including direct potentiometric measurement and indirect methods such as isopiestic measurement and solubility measurement. Next, progress on the various theoretical approaches was presented, ranging from analytical, empirical and simulation methods. Finally, challenges for future development are proposed on this field. [ABSTRACT FROM AUTHOR]

Unlike halides, where the kosmotropicity decreases from fluoride to iodide, the kosmotropic nature of halates apparently increases from chlorate to iodate, in spite of the lowering in the static ionic polarizability. In this paper, we present an experimental study that confirms the results of previous simulations. The lyotropic nature of aqueous solutions of sodium halates, i.e., NaClO3, NaBrO3, and NaIO3, is investigated through density, conductivity, viscosity, and refractive index measurements as a function of temperature and salt concentration. From the experimental data, we evaluate the activity coefficients and the salt polarizability and assess the anions' nature in terms of kosmotropicity/chaotropicity. The results clearly indicate that iodate behaves as a kosmotrope, while chlorate is a chaotrope, and bromate shows an intermediate nature. This experimental study confirms that, in the case of halates XO3−, the kosmotropic–chaotropic ranking reverses with respect to halides. We also discuss and revisit the role of the anion's polarizability in the interpretation of Hofmeister phenomena. [ABSTRACT FROM AUTHOR]

The ionic association constants of sodium with carbonate ion (K1C′) and acidic carbonate ions (K2C′) were measured in NaCl-NaHCO3-H2O ternary systems to determine the distribution of sodium among the chemical species present in the growth medium of Chlorella homosphaera 424 algae. The mean activity coefficients of sodium chloride (in pure sodium chloride and in a mixture of electrolytes) were determined experimentally using two electrochemical cells, namely Ag, AgCl| KCl (3 M)|| NH4NO3 (1 M)| NaCl (mNaCl)| Na+-ISE and Ag, AgCl|KCl (3 M)|| NH4NO3 (1 M)| NaCl (mNaCl)| Cl−-ISE. The studies carried out show that the values of the association constants of K1C′ and K2C′ do not depend on the composition of the medium, but only on the effective ionic strength. The experimentally obtained γNaCl0 values in the binary system are comparable to the mean activity coefficients values for NaCl, calculated using data from the literature, with −0.9 to 0.1% relative standard deviation. The obtained results show that the experimentally determined mean activity coefficient in the ternary system, γNaCl, is smaller than γNaCl0 in the binary system over the entire field of ionic strengths studied. The ternary system NaCl-NaHCO3-H2O obeys Harned’s rule.

In this work, the solubility of vanillic, gallic, syringic, p-coumaric, ferulic and caffeic acids was determined at 37 °C under different conditions, namely pure water and two different ionic media, NaCl(aq) and NaClO4(aq), at different ionic strengths (i.e., 0.16, 0.50, 1.0, 2.0 and 3.0 M). The solubility in water of all the acids was found to be higher than that in both of the ionic media. Moreover, the solubility of hydroxycinnamic acids was lower than that of hydroxybenzoic acids. The activity coefficients of neutral species were calculated from these data; this knowledge is necessary when modeling the dependence of equilibrium constants on the ionic strength. Results obtained in this work can be useful for further studies regarding complex formation equilibria between these ligands and bioavailable metal cations.

The application of a commonly used computer algorithm based on the group-additivity method for the calculation of the liquid viscosity coefficient at 293.15 K and the activity coefficient at infinite dilution in water at 298.15 K of organic molecules is presented. The method is based on the complete breakdown of the molecules into their constituting atoms, further subdividing them by their immediate neighborhood. A fast Gauss-Seidel fitting method using experimental data from literature is applied for the calculation of the atom groups' contributions. Plausibility tests have been carried out on each of the calculations using a ten-fold cross-validation procedure which confirms the excellent predictive quality of the method. The goodness of fit (Q²) and the standard deviation (σ) of the cross-validation calculations for the viscosity coefficient, expressed as log (η), was 0.9728 and 0.11, respectively, for 413 test molecules, and for the activity coefficient log(γ)∞ the corresponding values were 0.9736 and 0.31, respectively, for 621 test compounds. The present approach has proven its versatility in that it enabled the simultaneous evaluation of the liquid viscosity of normal organic compounds as well as of ionic liquids. [ABSTRACT FROM AUTHOR]

In this work, the solubility of vanillic, gallic, syringic, p-coumaric, ferulic and caffeic acids was determined at 37 °C under different conditions, namely pure water and two different ionic media, NaCl(aq) and NaClO4(aq), at different ionic strengths (i.e., 0.16, 0.50, 1.0, 2.0 and 3.0 M). The solubility in water of all the acids was found to be higher than that in both of the ionic media. Moreover, the solubility of hydroxycinnamic acids was lower than that of hydroxybenzoic acids. The activity coefficients of neutral species were calculated from these data; this knowledge is necessary when modeling the dependence of equilibrium constants on the ionic strength. Results obtained in this work can be useful for further studies regarding complex formation equilibria between these ligands and bioavailable metal cations. [ABSTRACT FROM AUTHOR]

We propose and test an efficient approach for the assessment of the enthalpies of vaporization of ionic liquids at the reference temperature 298.15 K. The approach is based on activity coefficients at infinite dilution of volatile organic solutes in ionic liquids bearing the imidazolium cation of the general formula [Cnmim][Anion]. [ABSTRACT FROM AUTHOR]

The solubility values and thermodynamic parameters of a natural phytomedicine/nutrient piperine (PPN) in Transcutol-HP (THP) + water combinations were determined. The mole fraction solubilities (xe) of PPN in THP + water combinations were recorded at T = 298.2–318.2 K and p = 0.1 MPa by the shake flask method. Hansen solubility parameters (HSPs) of PPN, pure THP, pure water and THP + water mixtures free of PPN were also computed. The xe values of PPN were correlated well with "Apelblat, Van't Hoff, Yalkowsky–Roseman, Jouyban–Acree and Jouyban–Acree–Van't Hoff" models with root mean square deviations of < 2.0%. The maximum and minimum xe value of PPN was found in pure THP (9.10 × 10−2 at T = 318.2 K) and pure water (1.03 × 10−5 at T = 298.2 K), respectively. In addition, HSP of PPN was observed more closed with that of pure THP. The thermodynamic parameters of PPN were obtained using the activity coefficient model. The results showed an endothermic dissolution of PPN at m = 0.6–1.0 in comparison to other THP + water combinations studied. In addition, PPN dissolution was recorded as entropy-driven at m = 0.8–1.0 compared with other THP + water mixtures evaluated. [ABSTRACT FROM AUTHOR]

The solubility and thermodynamic analysis of baricitinib (BNB) in various dimethyl sulfoxide (DMSO) + water mixtures were performed. The "mole fraction solubilities (xe)" of BNB in DMSO and water mixtures were determined at "T = 298.2–323.2 K" and "p = 0.1 MPa" using an isothermal saturation technique. "Hansen solubility parameters (HSPs)" of BNB, pure DMSO, pure water and "DMSO + water" mixtures free of BNB were also estimated. The xe data of BNB was regressed well by five different thermodynamics-based co-solvency models, which included "Apelblat, Van't Hoff, Yalkowsky-Roseman, Jouyban-Acree and Jouyban-Acree-Van't Hoff models" with overall deviations of <5.0%. The highest and lowest xe value of BNB was computed in pure DMSO (1.69 × 10−1 at T = 323.2 K) and pure water (2.23 × 10−5 at T = 298.2 K), respectively. The HSP of BNB was found to be closer to that of pure DMSO. Based on activity coefficient data, maximum solute–solvent molecular interactions were observed in BNB-DMSO compared to BNB-water. The results of "apparent thermodynamic analysis" indicated endothermic and entropy-drive dissolution of BNB in all "DMSO + water" combinations including mono-solvents (water and DMSO). "Enthalpy-entropy compensation analysis" showed enthalpy-driven to be the main mechanism of solvation of BNB. [ABSTRACT FROM AUTHOR]

This study was aimed to find out the solubility, thermodynamic behavior, Hansen solubility parameters and molecular interactions of an antiviral drug emtricitabine (ECT) in various "[polyethylene glycol-400 (PEG-400) + water]" mixtures. The solubility of ECT in mole fraction was determined at "T = 298.2 to 318.2 K" and "p = 0.1 MPa" using an isothermal method. The experimental solubilities of ECT in mole fraction were validated and correlated using various computational models which includes "Van't Hoff, Apelblat, Yalkowsky-Roseman, Jouyban-Acree and Jouyban-Acree-Van't Hoff models". All the models performed well in terms of model correlation. The solubility of ECT was increased with the raise in temperature in all "PEG-400 + water" mixtures studied. The highest and lowest solubility values of ECT were found in pure PEG-400 (1.45 × 10−1) at "T = 318.2 K" and pure water (7.95 × 10−3) at "T = 298.2 K", respectively. The quantitative values of activity coefficients indicated higher interactions at molecular level in ECT and PEG-400 combination compared with ECT and water combination. "Apparent thermodynamic analysis" showed an "endothermic and entropy-driven dissolution" of ECT in all "PEG-400 + water" combinations studied. The solvation nature of ECT was found an "enthalpy-driven" in each "PEG-400 + water" mixture studied. [ABSTRACT FROM AUTHOR]

In recent years, many papers describing ionic liquids (IL) as promising solvents in separation techniques have been published. The conscious choice of appropriate ionic liquid as absorption media in effective extraction of selected types of analytes requires deeper understanding of the analyte−IL interactions. Therefore, intensive research is conducted to determine the values of activity coefficient at infinite dilution, which allows us to characterize the nature of these interactions. Based on the inverse gas chromatography retention data, activity coefficients at infinite dilution γ 13 ∞ of 48 different organic compounds in the ionic liquids N-ethyl-N-methylmorpholinium bis(trifluoromethanesulfonyl)imide [C2C1Mor][TFSI] and N-octyl-N-methylmorpholinium bis(trifluoromethanesulfonyl)imide [C8C1Mor][TFSI] were determined. The measurements covered a broad range of volatile organic compounds, including n-alkanes, n-alkenes, n-alkynes, alcohols, aldehydes, ketones, aromatic compounds and common polar solvents, representing different types of interactions. Activity coefficients at infinite dilution were measured in the temperature range from 313.15 to 363.15 K. The excess partial molar enthalpies and entropies at infinite dilution were determined. Selectivity at infinite dilution was also calculated for exemplary separation processes in the hexane/benzene system. The obtained results were analyzed and compared with literature data for ionic liquids containing the same anion [TFSI]¯ and different cations. The study results indicate that some potential applications of the investigated ionic liquids in separation problems exist. [ABSTRACT FROM AUTHOR]

The current research work was performed to evaluate the solubilization behavior, solution thermodynamics, and solvation behavior of poorly soluble pyridazinone derivative i.e., 6-phenyl-pyridazin-3(2H)-one (PPD) in various binary solvent systems of dimethyl sulfoxide (DMSO) and water using experimental and various computational approaches. The solubility of PPD in various binary solvent system of DMSO and water was investigated within the temperature range T = 298.2 K to 318.2 K at constant air pressure p = 0.1 MPa, by employing an isothermal technique. The generated solubility data of PPD was computationally represented by five different cosolvency models including van't Hoff, Apelblat, Yalkowsky–Roseman, Jouyban–Acree, and Jouyban–Acree–van't Hoff models. The performance of each computational model for correlation studies was illustrated using root mean square deviations (RMSD). The overall RMSD value was obtained <2.0% for each computational model. The maximum solubility of PPD in mole fraction was recorded in neat DMSO (4.67 × 10−1 at T = 318.2 K), whereas the lowest one was obtained in neat water (5.82 × 10−6 at T = 298.2 K). The experimental solubility of PPD in mole fraction in neat DMSO was much higher than its ideal solubility, indicating the potential of DMSO for solubility enhancement of PPD. The computed values of activity coefficients showed maximum molecular interaction in PPD-DMSO compared with PPD-water. Thermodynamic evaluation showed an endothermic and entropy-driven dissolution of PPD in all the mixtures of DMSO and water. Additionally, enthalpy–entropy compensation evaluation indicated an enthalpy-driven mechanism as a driven mechanism for the solvation property of PPD. [ABSTRACT FROM AUTHOR]

Blueberries production has increased in the last few years boosted somehow by the World Health Organization (WHO) recommendations for a healthier nutrition and their recognized potential to treat several diseases. The production increase lead to high amounts of discarded leaves that could be very valuable. In this context, the antioxidant activity of Vaccinium spp. leaves, by means of the total phenolic (TPC) and flavonoid (TFC) content and total antioxidant capacity (TAC) was determined. Adult leaves of twenty-seven Vaccinium cultivars collected in three geographic regions and three seasons of the year were included. The antioxidant activity was additionally estimated with near infrared (NIR) spectroscopy and data transferability across the regions and seasons was evaluated. The TPC, TFC and TAC ranged from 39.6–272.8 mg gallic acid, 41.2–269.1 mg catechin and 22.6–124.8 mM Trolox per g of dry leaf, respectively. Globally through the seasons, the higher values of the three parameters were obtained in December. Regarding the geographic region, region A provided the cultivars with the higher antioxidant content. Titan was the cultivar with higher TPC and TAC and Misty the one with the higher TFC. NIR spectroscopy combined with the partial least squares analysis was able to successfully predict the antioxidant activity with coefficients of determination and range error ratios ranging from 0.84–0.99 and 11.2–26.8. Despite some identified limitations on data transferability, NIR spectroscopy proved to be a reliable, low cost and quick method to predict the antioxidant activity of the considered cultivar leaves. [ABSTRACT FROM AUTHOR]

The current research work proposed the solubility data and solution thermodynamic properties of the cardiovascular agent 6-phenylpyridazin-3(2H)-one [PPD] in twelve pharmaceutical solvents at "T = 298.2 K to 318.2 K" and "p = 0.1 MPa". The measured solubilities of PPD were regressed well with "van't Hoff and Apelblat models". The solid phases of pure and equilibrated PPD were characterized using differential scanning calorimetry and powder X-ray differactometry, and the results suggested no transformation of PPD into solvates/hydrates/polymorphs after equilibrium. The solubilities of PPD in a mole fraction at "T = 318.2 K" were noted at a maximum in dimethyl sulfoxide (DMSO, 4.73 × 10−1), followed by polyethylene glycol-400 (PEG-400, 4.12 × 10−1), Transcutol® (3.46 × 10−1), ethyl acetate (EA, 81 × 10−2), 2-butanol (2.18 × 10−2), 1-butanol (2.11 × 10−2), propylene glycol (PG, 1.50 × 10−2), isopropyl alcohol (IPA, 1.44 × 10−2), ethylene glycol (EG, 1.27 × 10−2), ethanol (8.22 × 10−3), methanol (5.18 × 10−3) and water (1.26 × 10−5). Similar tendencies were also noted at other studied temperatures. The results of the "apparent thermodynamic analysis" showed an endothermic and entropy-driven dissolution of PPD in all pharmaceutical solvents. The results of the activity coefficients suggested a maximum interaction at the molecular level in PPD-DMSO, PPD-PEG-400 and PPD-Transcutol, compared with other combination of the solute and solvents. [ABSTRACT FROM AUTHOR]

Estimating the solubility and solution thermodynamics parameters of aliskiren hemifumarate (AHF) in three different room temperature ionic liquids (RTILs), Transcutol-HP (THP) and water are interesting as there is no solubility data available in the literature. In the current study, the solubility and solution thermodynamics of AHF in three different RTILs, THP and water at the temperature range from 298.2 to 318.2 K under air pressure 0.1 MP were evaluated. The solid phase evaluation by Differential Scanning Calorimetry (DSC) and Powder X-ray Diffraction (PXRD) indicated no conversion of AHF into polymorph. The mole fraction solubility of AHF was found to be highest in 1-hexyl-3-methylimidazolium hexafluorophosphate (HMMHFP) ionic liquid (7.46 × 10−2) at 318.2 K. The obtained solubility values of AHF was regressed by the Apelblat and van't Hoff models with overall root mean square deviations (RMSD) of 0.62% and 1.42%, respectively. The ideal solubility of AHF was higher compared to experimental solubility values at different temperatures. The lowest activity coefficient was found in HMMHFP, which confirmed highest molecular interaction between AHF–HMMHFP. The estimated thermodynamic parameters confirmed endothermic and entropy driven dissolution of AHF in different RTILs, THP, and water. [ABSTRACT FROM AUTHOR]

Deep eutectic solvents (DESs) are potential alternatives to many conventional solvents in process applications. Knowledge and understanding of solid–liquid equilibria (SLE) are essential to characterize, design, and select a DES for a specific application. The present study highlights the main aspects that should be taken into account to yield better modeling, prediction, and understanding of SLE in DESs. The work is a comprehensive study of the parameters required for thermodynamic modeling of SLE—i.e., the melting properties of pure DES constituents and their activity coefficients in the liquid phase. The study is carried out for a hypothetical binary mixture as well as for selected real DESs. It was found that the deepest eutectic temperature is possible for components with low melting enthalpies and strong negative deviations from ideality in the liquid phase. In fact, changing the melting enthalpy value of a component means a change in the difference between solid and liquid reference state chemical potentials which results in different values of activity coefficients, leading to different interpretations and even misinterpretations of interactions in the liquid phase. Therefore, along with reliable modeling of liquid phase non-ideality in DESs, accurate estimation of the melting properties of their pure constituents is of clear significance in understanding their SLE behavior and for designing new DES systems. [ABSTRACT FROM AUTHOR]