Solubility Behavior Research Articles

Effect of free energy on the solid solubility and magnetic behaviour of a mechanically alloyed nanocrystalline Cu–Co–Ti alloy

Effect of free energy on the solid solubility and magnetic behaviour of a mechanically alloyed nanocrystalline Cu–Co–Ti alloy

Study on co-amorphous emerging solubilization behavior after gelation during dissolution: The importance of complexation and anti-crystallization

Co-amorphous (CM) is a promising technology for enhancing the aqueous solubility of insoluble drugs, but the gelation phenomenon has often occurred during the dissolution process and seriously threatened their solubility/dissolution performance. Therefore, it’s quite important to design favorable CM systems to alleviate or even avoid the adverse effects of gelation phenomenon. In this study, CM systems of taxifolin (TAX) and oxymatrine (OMT) (TAX-OMT CMs) were constructed to improve the solubility and dissolution properties of TAX. Interestingly, TAX-OMT CMs gradually aggregated and obviously gelled during dissolution, but the solubility and dissolution of TAX in TAX-OMT CMs were significantly enhanced compared to crystalline TAX. Consequently, the underlying solubilization mechanisms of TAX-OMT CMs after gelation were systematically explored. For one thing, the complexation between the two components in TAX-OMT CMs was verified by phase solubility, fluorescence spectroscopy and isothermal titration calorimetry. For another, the residual solids of TAX-OMT CMs after dissolution evaluation were thoroughly characterized by means of powder X-ray diffraction, fourier transform infrared spectroscopy, scanning electron microscopy, which showed the anti-crystallization property of TAX-OMT CMs. Furthermore, molecular simulation demonstrated the intermolecular interactions of TAX-OMT CMs alone and TAX-OMT complexes in aqueous solution. Finally, pharmacokinetics study in rats suggested that the bioavailability of TAX in TAX-OMT CM (1:2) was approximately 5.5-fold higher than that of crystalline TAX after oral administration. Collectively, this study reveals the importance of complexation and anti-crystallization effects of CM systems on maintaining solubilization behavior after gelation, providing an effective strategy to improve the absorption performance of pharmaceutical CM systems.

Photophysicochemical properties of pyrazoline substituted ZnII-phthalocyanine-based photosensitizers

Cancer has grown to be a global issue and has put strain on the healthcare system in recent years. Promising alternatives for the treatment of cancer include photodynamic therapy (PDT). For therapeutic purposes, phthalocyanines have been widely employed as sensitizers, especially for photodynamic treatment (PDT). The primary goal of this work is to examine the photophysicochemical properties of newly synthesized and characterized pyrazoline substituted peripherally tetra substituted and non-peripherally tetra substituted ZnII-phthalocyanines. Several techniques were applied during the characterization of the novel compounds, such as mass (MALDI-TOF), nuclear magnetic resonance (NMR), infrared (FT-IR), and UV–Vis spectroscopies. The impact of substituting 3-(5-(4-(dimethylamino)phenyl)-1-phenyl-4,5-dihydro-1H-pyrazole-3-yl)phenol from the peripheral and non-peripheral positions on solubility and aggregation behaviors was examined. The newly synthesized pyrazoline substituted ZnII-phthalocyanines display high solubility in common organic solvents and additionally do not aggregate at concentrations from 1 to 10 μM. The potential use of the pyrazoline substituted ZnII-phthalocyanines as a photosensitizers in photodynamic therapy was investigated by examining their photophysical and photochemical properties. Non-peripheral pyrazoline substituted ZnII-phthalocyanine (HY-ZnPcnp) may be a potential photosensitizer for PDT, owing to an examination of the results.

Difenoconazole solubility in acetonitrile/N,N-dimethylformamide/acetone + water and quantum chemistry study into inter/intra-molecular interactions

The difenoconazole solubilities in acetonitrile/acetone/N,N-dimethylformamide (DMF) + water systems were acquired experimentally with the help of the isothermal shake-flask technique. Analysis of X-ray power diffraction revealed that difenoconazole did not exhibit any crystal transition as well as solvate formation. The solubility acquired here was accurately correlated, which yielded relative average deviations (RAD) of ≤4.99 % and a root-mean-square deviation of ≤20.59 × 10−5 through the Jouyban-Acree and modified van’t Hoff-Jouyban-Acree models Additionally, to explain the solubility behavior at a temperature of 298.15 K, this work examines the acetonitrile/acetone/DMF + water and the previously published methanol/ethanol/isopropanol/PG + water blends utilizing the extended Hildebrand solubility technique. The RAD levels remained below 6.88 %. The dipolarity-polarizability and the solubility parameter of blended solvents exert a substantial impact on the variability of difenoconazole solubility. The preferred solvation of difenoconazole at a temperature of 298.15 K was examined through the inverse Kirkwood-Buff integrals. The solvation parameters’ values of difenoconazole were positive in blends containing methanol, acetone, DMF, ethanol, isopropanol, and acetonitrile with moderate and rich compositions. This indicates that difenoconazole is preferentially solvated by them in above composition ranges. A shift from an enthalpy-driven mechanism to an entropy-driven one was revealed through an analysis of the thermodynamics of the entropy-enthalpy relationship in the dissolution of difenoconazole in blends. Furthermore, the mean local ionization energy, Hirshfeld surface as well as molecular surface electrostatic potential were employed to illustrate the microscopic electrostatic characteristics. The N and N groups in the five-membered ring of difenoconazole molecule are the primary sites for electrophilic attack. The weak contacts of difenoconazole-solvent were demonstrated with the help of a Hirshfeld partition analysis-based independent gradient model.

Solubility behavior and solvation effect of a photomechanical molecular crystal trans-4-chlorocinnamic acid in twelve neat solvents at temperatures from 283.15 to 323.15 K

Solubility of trans-4-chlorocinnamic acid as a photomechanical molecular crystal material in twelve pure solvents (water, ethanol, methanol, n-propanol, isopropanol, n-butanol, isobutanol, acetonitrile, 1,4-dioxane, acetone, methyl acetate and ethyl acetate) were measured from 283.15 to 325.15 K at 101.2 kPa. The results showed that the trans-4-chlorocinnamic acid solubility increased with the temperature, the order is: 1,4-dioxane > acetone > n-butanol > ethanol > n-propanol > isopropanol > isobutanol > methanol > methyl acetate > ethyl acetate > acetonitrile > water. Powder X-ray diffraction pattern (PXRD) and differential scanning calorimetry (DSC) were used to identify and characterize the equilibrated solid phase samples. The solubility behavior and the solute–solvent interaction of trans-4-chlorocinnamic acid in each selected mono-solvent were explored by the empirical solvents polarity parameter (ET(30)), hydrogen bonding, cohesive energy density, molecular structure, and Hansen solubility parameters (HSPs). In addition, the experimental solubility data were correlated by the modified Apelblat model and Yaws model, and the fitting results of this models were all satisfactory. The intermolecular forces were determined through molecular simulations, including Hirshfeld surface (HS) and Molecular Electrostatic Potential Surface (MEPS) analysis. The results showed that hydrogen bond can be formed between trans-4-chlorocinnamic acid and the selected solvents, which can help to further explain the dissolution behavior of trans-4-chlorocinnamic acid in the solvents.

Investigation on itraconazole solubility in aqueous solutions based on models, solvent effect, thermodynamic analysis and quantum chemical calculations

The mole-fraction solubility of itraconazole in four aqueous blends of ethanol/isopropanol/DMSO/methanol within the temperature range of 283.15 to 323.15 K was experimentally obtained using the isothermal shake-flask method. Under the identical temperature and ethanol/isopropanol/DMSO/methanol composition, itraconazole solubility in DMSO+water is much higher than that in ethanol/isopropanol/methanol + water. At the same temperature, the solubility increases monotonically with organic solvent concentration. X-ray power diffraction analysis demonstrated that over the course of the investigations, there was no crystal transition or solvate formation. The modified van’t Hoff-Jouyban-Acree and Jouyban-Acree models adequately related the solubility to solvent composition and temperature, with relative average deviations (RADs) not exceeding 7.65 %. Furthermore, the extended Hildebrand solubility approach was utilized to quantitatively characterize the solubility behavior at 298.15 K for the mixtures of ethanol/isopropanol/DMSO/methanol plus water. In both instances, the RADs were maintained below 4.12 %. The solubility parameter and dipolarity-polarizability of solutions have a major impact on the solubility fluctuation, as indicated by the analysis of the linear solvation energy relationship. The preferential solvation of itraconazole at 298.15 K was examined using the efficient approach of inverse Kirkwood-Buff integrals. The preferred solvation parameters showed positive values in blends within rich and moderate ethanol/isopropanol/DMSO/methanol composition regions. This suggests that the organic solvents preferentially solvated itraconazole. When itraconazole dissolved in the blends, thermodynamic analysis of the entropy-enthalpy compensation and dissolution parameters revealed both an endothermic and an enthalpy-driven mechanism. Furthermore, the microscopic electrostatic characteristics of basicity and acidity were effectively demonstrated by means of the electrostatic potential of molecular surface. The −C=O and −N=groups of the itraconazole molecule, which link the five-membered ring, are the primary targets of the electrophilic attack. An independent gradient model based on Hirshfeld partition analysis was used to demonstrate the weak interactions between itraconazole and solvents.

Enhancing 3DSPs estimation: The dispersive solubility parameter adjusted by means of molar refraction, coordination number and molar volume using the DiPEVa model

This study comprehensively analyzes the empirical relationships between polarizability measurements, such as refractivity index and molar refraction, or the length of the homologous chain (HCL), and the dispersive solubility parameter (δD). The authors investigated the correlation between these parameters by utilizing a database encompassing various chemical groups across a range of aliphatic and aromatic molecules. An innovative approache enhaces the well known relationship between the the dispersive solubility parameter (δD) and the Lorentz-Lorenz function, adjusting the dispersive solubility parameters by the ratio of coordination numbers and molar volumes as correction factors. Notably, the adjusted δD demonstrated a strong linear correlation with MR, suggesting that MR can be a reliable predictor for δD. This was further substantiated by the strong correlation coefficients obtained (such as an adjusted R-Square of 0.866), indicating the robustness of our empirical models. In conclusion, our research provides new insights into the solubility behaviour of molecules with the derived empirical relationships offering a valuable tool for predicting solubility parameters. These findings have practical implications for solvent selection, understanding liquid behaviours, and the design of chemical processes and materials.

Molecular mechanism underlying coencapsulating chrysophanol and hesperidin in octenylsuccinated β-glucan aggregates for improving their corelease and bioaccessibility

Chrysophanol and hesperidin are natural nutraceuticals that exhibit synergistic bioactivities, but their hydrophobicity limits their applications, and it is unclear whether coencapsulation can improve their solubility and release behaviors. The objective of this work was to coencapsulate chrysophanol and hesperidin by octenylsuccinated β-glucan aggregates (OSβG-Agg) and to reveal how coencapsulation improves their release and bioaccessibility. Mechanisms underlying the hypothesis of beneficial effects in coloading, corelease and bioaccessibility were revealed. The solubilization of OSβG-Agg was due to hydrogen-bonding among β-glucan moieties of OSβG and hydroxyl groups of chrysophanol and hesperidin and hydrophobic interactions among octenyl chains of OSβG and hydrophobic moieties of chrysophanol and hesperidin. Structural analyses confirmed the hypothesis that chrysophanol molecules were nearly embedded deeper into the interior of hydrophobic domains, and most of hesperidin molecules were incorporated into the exterior of the hydrophobic domains of OSβG-Agg due to the strength of these interactions, but they interacted in OSβG-Agg with a dense and compact structure rather than existing in isolation. The combined effects delayed their release and enhanced their bioaccessibility because of dynamic equilibrium between the favorable interactions and unfavorable structural erosion and relaxation of OSβG-Agg. Overall, OSβG-Agg is effective at codelivering hydrophobic phenolics for functional foods and pharmaceuticals.

Improving the solubilization, stability, dialysis performance and antioxidant properties of quercetin in surfactant-free microemulsion

The flavonol compound quercetin with poor water solubility, was solubilized in a novel green solvent constructed in this work. The solvent is composed of tributyl citrate, ethanol and water, recognized as surfactant-free microemulsion (SFME). The solubilization behavior and mechanism of quercetin were investigated, the light, thermal, storage stability and antioxidant properties were examined, as well as the dialysis properties and release kinetics. The results reveal that there are interactions existing between quercetin and tributyl citrate. Ethanol and tributyl citrate in SFME also have a synergistic solubilization effect on quercetin. Therefore, the content of quercetin increases with tributyl citrate, and the solubility of quercetin in oil in water SFME (RE/W = 7:3, ƒO = 0.1) is 9.88 mg/ml, much higher than that in water or ethanol. The light, heat, storage stability and antioxidant properties of quercetin are greatly improved by SFME. In the dialysis process, the release of quercetin in SFME follows a non-Fickian diffusion mechanism with a slow-release action. The SFME established has green and non-toxic advantages in the application of the solubilization field, and it is expected to provide important guidance for the extraction and separation of natural foods.

Hierarchical Self-Aggregation of Multifunctional Steviol Glycosides in Aqueous Solutions.

Steviol glycosides (SGs) are a natural sweetener widely used in the food and beverage industry, but the low solubility and stability of SG aqueous solutions greatly limit their application performance, especially in liquid formulations. In this work, we explore the solubility behavior of rebaudioside A (Reb A) in water, a major component of SGs, with the aim of clarifying the underlying mechanisms of the solubility and stability constraints of SGs, as well as the impact on their multifunctional properties. We demonstrate for the first time that Reb A exhibits hierarchical self-assembly in solutions, forming spherical micelles first when the concentration exceeds its critical micelle concentration (5.071 mg/mL), which then further assemble into large rod-like aggregates. The formation of such large Reb A aggregates is mainly dominated by hydrogen bonding and short-range Coulomb interaction energy, thus leading to the low solubility and precipitation of Reb A solutions. Surprisingly, aggregated Reb A structures display significantly improved organoleptic properties, revealing that self-aggregation can be developed as a simple, efficient, and green strategy for improving the taste profile of SGs. Additionally, the self-aggregation of Reb A at high concentrations impairs active encapsulation and also affects its interfacial and emulsifying properties.

Solubility Behavior, Hansen Solubility Parameters, and Thermodynamic Modeling of 9-Phenylcarbazole in 12 Monosolvents from 283.15 to 323.15 K

Solubility Behavior, Hansen Solubility Parameters, and Thermodynamic Modeling of 9-Phenylcarbazole in 12 Monosolvents from 283.15 to 323.15 K

Study of celecoxib dissolution process in the mixtures of ethanol and propylene glycol at different temperatures

ABSTRACT Categorised as a nonsteroidal anti-inflammatory drug targeting the COX-2 enzyme over COX-1, celecoxib (CXB) demonstrates high membrane permeability and low aqueous solubility, placing it in class II of the biopharmaceutical classification system. Therefore, comprehension of its solubility behaviour under different configurations is desirable. The current study explores CXB solubility in propylene glycol and ethanol binary mixtures by varying temperature and cosolvent concentration, using the shake-flask method followed by spectroscopy analysis. The results show increased solubility of CXB in this mixture as ethanol mass fraction and temperature increase. Several cosolvency models were used to correlate data, including van't Hoff, Jouyban-Acree, Jouyban-Acree-van't Hoff, and mixture response surface/modified Wilson models. The mathematical models’ accuracy was investigated through mean relative deviation. The Gibbs and van't Hoff equations were employed to establish the thermodynamic features of CXB dissolution.

Screening of ionic liquids for the solubility enhancement of quinine using COSMO-RS

Quinine has traditionally been used in medicine to treat parasitic disease malaria due to its antimalarial activities. It is sparingly soluble in water and highly soluble in organic solvents. However, these solvents are not environmentally friendly, so greener solvents need to be explored and designed. Ionic liquids (ILs) were successfully observed to be greener and capable of dissolving biologically active compounds. However, finding a potential IL from millions of possible IL combinations is challenging. This work utilizes the conductor-like screening model for real solvents (COSMO-RS) to address this issue. This study aims to determine the dissolution behavior of quinine in ILs employing the COSMO-RS. A total of 540 IL combinations of 9 cations and 60 anions were investigated. The efficacy of each IL was evaluated by predicting the activity coefficients at infinite dilution, solvation-free energy, selectivity, capacity, and performance index (P.I.). This study reveals that ILs with shorter alkyl chains, polar and non-aromatic characteristics, and smaller anions are advantageous for the solubility enhancement ofquinine.The most effective ILs, choline acetate, choline glycinate, and choline threoninate, displayed the highest selectivity, capacity, P.I., and lowest activity coefficient and solvation-free energies. The findings of the current study unlock key insights into the solubility behaviour of quinine in an aqueous solution employing ILs.

Solubility Behavior and Data Correlation of N-Acetyl-l-valine in 12 Individual Solvents at Multiple Temperatures

Solubility Behavior and Data Correlation of <i>N-</i>Acetyl-<scp>l</scp>-valine in 12 Individual Solvents at Multiple Temperatures

In Silico and In Vitro Alpha-amylase Activities of Previously Synthesized Pyridazine Derivatives

Diabetes mellitus is one of the fastest-growing metabolic disorders. Worldwide, one out of 10 people suffer from diabetes mellitus. In this manuscript, we establish the antidiabetic potential of previously synthesized pyridazine derivatives using in silico and in vitro experiments. Molecular docking studies of pyridazine derivatives with pullulanase Amy12, isomaltase, and alpha-amylase receptors revealed that Molecules 45, 46, and 29 showed good docking interaction scores. ADMET analysis of the top three docked pyridazine derivatives (45, 46, and 29) showed lesser solubility and poor distribution behavior. Molecules 45, 46, and 29 maintained drug-like properties with good oral bioavailability. Molecules 45 and 29 showed reproductive toxicity without any sign of mutagenicity, tumorigenicity, or other irritancy. Molecule 46 emerged as a nontoxic molecule in all aspects. In vitro alpha-amylase inhibition data of molecules 45, 46, 29, and acarbose showed IC50 values of 8.67, 8.46, 8.83, and 66.65 μg/mL, respectively. The antidiabetic activity of pyridazine derivatives is increased with the presence of phenothiazine coupled with a biphenyl group, indole with a biphenyl group, and phenothiazine with an ethylphenyl group. Establishing these pyridazine derivatives using in vivo experiments could be beneficial in managing diabetes.

Improved Rigidin-Inspired Antiproliferative Agents with Modifications on the 7-Deazahypoxanthine C7/C8 Ring Systems.

To improve their aqueous solubility characteristics, water-solubilizing groups were added to some antiproliferative, rigidin-inspired 7-deazahypoxanthine frameworks after molecular modeling seemed to indicate that structural modifications on the C7 and/or C8 phenyl groups would be beneficial. To this end, two sets of 7-deazahypoxanthines were synthesized by way of a multicomponent reaction approach. It was subsequently determined that their antiproliferative activity against HeLa cells was retained for those derivatives with a glycol ether at the 4'-position of the C8 aryl ring system, while also significantly improving their solubility behavior. The best of these compounds were the equipotent 6-[4-(2-ethoxyethoxy)benzoyl]-2-(pent-4-yn-1-yl)-5-phenyl-1,7-dihydro-4H-pyrrolo[2,3-d]pyrimidin-4-one 33 and 6-[4-(2-ethoxyethoxy)benzoyl]-5-(3-fluorophenyl)-2-(pent-4-yn-1-yl)-1,7-dihydro-4H-pyrrolo[2,3-d]pyrimidin-4-one 59. Similarly to the parent 1, the new derivatives were also potent inhibitors of tubulin assembly. In treated HeLa cells, live cell confocal microscopy demonstrated their impact on microtubulin dynamics and spindle morphology, which is the upstream trigger of mitotic delay and cell death.

Highly Soluble Dacarbazine Multicomponent Crystals Less Prone to Photodegradation.

Dacarbazine (DTIC) is a widely prescribed oncolytic agent to treat advanced malignant melanomas. Nevertheless, the drug is known for exhibiting low and pH-dependent solubility, in addition to being photosensitive. These features imply the formation of the inactive photodegradation product 2-azahypoxanthine (2-AZA) during pharmaceutical manufacturing and even drug administration. We have focused on developing novel DTIC salt/cocrystal forms with enhanced solubility and dissolution behaviors to overcome or minimize this undesirable biopharmaceutical profile. By cocrystallization techniques, two salts, two cocrystals, and one salt-cocrystal have been successfully prepared through reactions with aliphatic carboxylic acids. A detailed structural study of these new multicomponent crystals was conducted using X-ray diffraction (SCXRD, PXRD), spectroscopic (FT-IR and 1H NMR), and thermal (TG and DSC) analyses. Most DTIC crystal forms reported display substantial enhancements in solubility (up to 19-fold), with faster intrinsic dissolution rates (from 1.3 to 22-fold), contributing positively to reducing the photodegradation of DTIC in solution. These findings reinforce the potential of these new solid forms to enhance the limited DTIC biopharmaceutical profile.

Fabricating supramolecular lyotropic crystals at subzero temperatures: The pivotal role of antifreeze and nanostructures

The classical lyotropic liquid crystals (LLCs) prepared in pure water are not adapted to subzero temperatures. However, the fabrication of cryogenic LLCs is highly significant for gaining profound insights into self-assembly at extremely low temperatures. A proficient solution strategy, namely introducing alcohol antifreeze to water, faces a challenge in balancing frozen resistance and efficient self-assembly. Herein, we address this unmet challenge by selecting four alcohols with comparable structure to fabricate cryogenic LLCs system through the supramolecular self-assembly of a long-chain non-ionic surfactant. The freezing point, surfactant solubility, and self-assembly behavior at subzero temperatures were investigated. The alcohol antifreeze plays a significant role in depressing water freezing point and governing assembled microstructures. Both experimental and computational results revealed that alcohols bearing more hydroxyl groups are efficient to lower water freezing point while remain the capability to induce surfactant self-assembly. They can realize solvophobic balance and strong hydrogen-bond interactions. A simple approach based on Gordon parameter was established to evaluate the suitability as an anti-freezing medium for amphiphile self-assembly. Strikingly, a new LLCs system capable of withstanding the extremely low temperature of −80 °C was developed, which shows interestingly continuous phase transitions as temperature lowers to subzero. Overall, this study provides valuable insights into cryogenic supramolecular self-assembly, and offers a significant foundation and evaluation method for the selection of appropriate alcohol antifreeze for cryogenic self-assembly.

Supercritical CO2 extraction of Walnut (Juglans regia L.) oil: Extraction kinetics and solubility determination

Experimental and modelling investigations of supercritical CO2 extraction of oil from Juglans regia L. kernels were conducted at 200 and 400 bar, 313 and 333 K at a CO2 flow rate of 0.1 kg/h. Regardless of the pressure and the temperature, the highest achievable yield was estimated at about 0.7 kgoil / kgbiomass. The extraction kinetics were modeled with Sovová’s broken and intact cells model. Walnut oil apparent solubility in supercritical CO2 was determined and modelled with the Chrastil equation. A retrograde solubility behaviour was observed at 200 bar, the faster extraction kinetics were found at 400 bar and 333 K. The fatty acid composition of the supercritical CO2 extracted oil was compared to the quality of the oil extracted by press and n-hexane Soxhlet extraction.

Effect of novel surfactant protic ethanolamine based ionic liquids on the aqueous solubility and thermodynamic properties of acetaminophen

The solubility of poorly soluble drugs in aqueous media remains an obstacle in the pharmaceutical development process. Ionic liquids (ILs), with their remarkable solvent properties, have gained considerable attention as potential solubility enhancers for such drugs. In this context, surfactant protic ethanolamine-based ILs have emerged as a particularly promising class of compounds due to their unique dual functionality. This study explores the significant role of these novel solvents in improving drug solubility, focusing on their potential applications in pharmaceutical formulations. Acetaminophen (ACP), a widely used analgesic and antipyretic drug, often encounters solubility limitations that hinder its effective pharmaceutical applications. In the past few years, there has been a growing recognition of the potential of ILs (ionic liquids) as effective solvents. They offer promising prospects for enhancing the solubility of pharmaceutical substances in water-based solutions. This study investigates the enhancement of ACP solubility through the utilization of ILs. The solubilization behavior of ACP in the attendance of mono, bis and tris-(2-hydroxyethylammonium) octanoate systems is explored, highlighting the significant impact of different number of hydroxyethyl groups combinations on its solubility profile. Experimental results reveal that these ILs exhibit a remarkable ability to improve the solubility of ACP, making them attractive candidates for pharmaceutical formulations. The mechanisms underlying this enhancement are discussed, encompassing factors such as the ion-specific interactions, polarity, and hydrogen bonding capabilities of ionic liquids. Furthermore, the potential implications of utilizing ILs for enhancing the bioavailability and formulation versatility of ACP are considered. To accurately correlate the solubility data, various thermodynamic models were employed. Furthermore, to examine the observable thermodynamic characteristics of dissolution in the studied systems Van't Hoff and Gibbs equations were used. The findings indicated that the dissolution process in all co-solvents used was characterized by an endothermic nature and driven by enthalpy.