Experimental Mole Fraction Research Articles

Measurement and correlation of solubility data for sodium picosulphate in selected pure solvents and mixed-solvent systems from 298.15 K to 328.15 K

An investigation was carried out to determine the solubility of the stimulant laxative drug Sodium Picosulphate (SP). A wide range of pure solvents were studied, including methanol, ethanol, 1-propanol, 1-butanol, dimethyl formamide, dimethyl sulfoxide, acetonitrile, 1,4-dioxane, acetic acid, and water. More to the point, the solubility of the compound was determined using mixed solvent systems; methanol + acetonitrile and water + acetonitrile. Experimental mole fraction solubility of SP was determined by the gravimetric method over a range of temperatures (298.15 K to 328.15 K) under atmospheric pressure (p=0.1MPa). According to experimental results, a temperature-dependent relationship exists between solubility and temperature. Further, we correlated the experimental mole fraction solubility data with theoretical models including Apelblat, Yaws, Van't Hoff, Modified Jouyban-Acree, CNIBS/R-K models. It appears that the results are well in agreement with the experimental results due to the small values of relative average deviation (RAD) and root mean square deviation (RMSD).The solubility data might be useful in the various areas such as modification, production, crystallization, and separation of SP.

HSPiP, Computational, and Thermodynamic Model-Based Optimized Solvents for Subcutaneous Delivery of Tolterodine Tartrate and GastroPlus-Based In Vivo Prediction in Humans: Part I.

Tolterodine tartrate (TOTA) is associated with adverse effect, high hepatic access, varied bioavailability, slight aqueous solubility, and short half-life after oral delivery. Hansen solubility parameters (HSP, HSPiP program), experimental solubility (T = 298.2 to 318.2K and p = 0.1MPa), computational (van't Hoff and Apelblat models), and thermodynamic models were used to the select solvent(s). HSPiP predicted PEG400 as the most suitable co-solvent based on HSP values (δd = 17.88, δp = 4.0, and δh = 8.8 of PEG400) and comparable to the drug (δd = 17.6, δp = 2.4, and δh = 4.6 of TOTA). The experimental mole fraction solubility of TOTA was maximum (xe = 0.0852) in PEG400 confirming the best fit of the prediction. The observed highest solubility was attributed to the δp and δh interacting forces. The activity coefficient (ϒi) was found to be increased with temperature. The higher values of r2 (linear regression coefficient) and low RMSD (root mean square deviation) indicated a good correlation between the generated "xe" data for crystalline TOTA and the explored models (modified Apelblat and van't Hoff models). TOTA solubility in "PEG400 + water mixture" was endothermic and entropy-driven. IR (immediate release product) formulation can be tailored using 60% PEG400 in buffer solution for 2mg of TOTA in 0.25mL (dosing volume). The isotonic binary solution was associated with a pH of 7.2 suitable for sub-Q delivery. The approach would be a promising alternative with ease of delivery to children and aged patients.

Determination of solubility of sildenafil citrate in propylene glycol + 2-propanol and N-methyl pyrrolidone + water: Comparing solubilization power of aqueous or non-aqueous mixtures

For identifying the solubilization power of aqueous and non-aqueous solvent mixtures for sildenafil citrate (SLC), its solubility was determined in four mono-solvents of propylene glycol, 2-propanol, N-methyl pyrrolidone and water along with the binary solvent mixtures of propylene glycol + 2-propanol and N-methyl pyrrolidone + water at 293.2 to 313.2 K and at pressure of 85 kPa. Among the neat organic solvents and also water, N-methyl pyrrolidone presented a high solubilization power for SLC (8.66 × 10-2 at 313.2 K) and its aqueous binary mixtures had also a more ability to solubilize the drug in compared with the binary (propylene glycol + 2-propanol) mixtures (with the highest value of 4.96 × 10–4 at 313.2 K). Besides, increasing the solubility of SLC with raising temperature illustrated that its dissolution in the aforementioned mixtures was endothermic. The equilibrium solid phase crystal of SLC was also characterized with X-ray powder diffraction analysis to identify no polymorphic transformation, solvate formation or crystal transition during the whole solvent crystallization process. Moreover, the experimental mole fractions were modelled by used commonly cosolvency models and regressed the model parameters. The back-calculated mole fractions of SLC by cosolvency models shown a better agreement with the experimental data (overall mean percentage deviation (OMPD) ≤ 7.6 %) and Jouyban-Acree model as a function of temperature and solvent compositions had the best performance (MPD of 3.2 %). Furthermore, the solubility data sets of SLC in 7 binary solvent mixtures were collected from the literature and correlated with the Jouyban-Acree model and its derivates, the OMPDs for the back-computed solubility indicating the generally trained models, especially Jouyban-Acree-Abraham model (MPD of 24.2 %), had an acceptable ability in the prediction of SLC solubility and can be useful in the pharmaceutical industry. Finally, apparent thermodynamic properties of Gibbs free energy, standard enthalpy and entropy of the dissolution processes were also investigated.

Equilibrium solubility, solvent effect, and equation correlations of cyclosporine in twenty mono solvents and four binary mixtures

In this study, the solid–liquid equilibrium solubility of cyclosporine in 20 pure solvents and four binary mixtures at 298.15 K were determined using shake-flask technique. Solid-state characterization exhibited that no solvate formation or polymorphic transformation occurred during the dissolution of cyclosporine in any of the solvent systems investigated. The experimental solubilities of cyclosporine in 20 pure mono solvents were ranked as follows: DEGME (2.21 × 10−1) > ethanol (1.22 × 10−1) > NMP (1.15 × 10−1) = 1-butanol (1.15 × 10−1) > dichloromethane (1.07 × 10−1) > acetonitrile (1.02 × 10−1) > PEG 200 (9.78 × 10−2) > PEG 300 (9.12 × 10−2) > chloroform (8.98 × 10−2) > PEG 400 (8.11 × 10−2) > DMF (7.65 × 10−2) > 2-propanol (7.09 × 10−2) > 1-propanol (6.57 × 10−2) > methanol (6.14 × 10−2) > propylene glycol (6.08 × 10−2) > tetrahydrofuran (4.69 × 10−2) > DMSO (2.64 × 10−2) > acetone (1.28 × 10−2) > glycerol (1.35 × 10−5) > water (4.29 × 10−7). In the four binary solvents (DEGME + water, PEG 200 + water, PEG 300 + water, and PEG 400 + water), the mole fraction solubility of cyclosporine increased with increasing mass fractions of the four different organic solvents. Based on the Kamlet-Taft linear solvation energy relationship (KAT-LSER) model, the solubility of cyclosporine was mainly affected by the self-cohesiveness of the solvent, which is related to the interaction between the solvent and the solvent. Additionally, the solubility parameter was used to explain and understand the solubility of cyclosporine in four different binary solvents. To correlate the solubility data of cyclosporine, two models (the Yalkowsky Log-Linear and simplified CNIBS/R–K models) were applied. The calculated data based on two mathematical models and experimental mole fraction solubility data for cyclosporine could provide information for the separation, extraction, purification, crystallization, and selection of suitable a solvent system.

Impact of polyethylene glycol molar mass and structural isomer of alcohol on the solubility and dissolution enhancement of mesalazine

This work reports the solubility of mesalazine (5-ASA) in mole fraction terms (x1,T) in mono-solvents of polyethylene glycol (PEG) 400, 1-propanol and 2-propanol along with their binary mixtures in different mass fractions of PEG 400 at 293.15–313.15 K and atmospheric pressure which measured experimentally by a shake-flask technique. The solubility of 5-ASA in these mixtures not only enhances with enhancing temperature, but also raises with raising PEG's mass fraction. Effect of PEG molar mass on the solubility of 5-ASA was also estimated by measuring its solubility in PEG 200 or 600 + 1- or 2-propanol mixtures at 298.15 K. Upon the same temperature and mass fraction of PEGs, the upward trend of 5-ASA mole fractions was: PEG 600 + 1-propanol > PEG 600 + 2-propanol > PEG 400 + 1-propanol > PEG 400 + 2-propanol > PEG 200 + 1-propanol > PEG 200 + 2-propanol indicating, the binary mixtures containing a high molar mass of PEG and 1-propanol with a hydroxyl group attached to carbon number 1 had a more solubilization power. Then, the experimental mole fractions were modelled by some cosolvency and activity coefficient models, and the model parameters were regressed. The back-computed mole fractions of 5-ASA by cosolvency models presented a better agreement with the experimental data than that of activity models and Jouyban-Acree model had the best performance (low overall average percentage deviation of 6.1 %). By means of enthalpy-entropy compensation analysis, non-linear ΔsolH° against ΔsolG° compensation plots with positive and negative slopes were achieved as a consequent of increasing 5-ASA solvation by PEG molecules and the solvent-structure loosing, respectively.

Comments on “Study on 2-amino-4-chloro-6-methoxypyrimidine in four binary solvent mixtures: Solubility measurement, calculation, preferential solvation and extended Hildebrand solubility parameter approach analysis”

A polemic is given regarding the apparent Gibbs energies of dissolution reported by Huang and Yao for 2-amino-4-chloro-6-methoxypyrimidine dissolved in four binary aqueous-organic solvent mixtures at the harmonic mean temperature. Our reanalysis of the authors’ experimental mole fraction solubility data yielded positive values, rather than negative values, for the apparent Gibbs energies of dissolution.

Characterization and gasification of end-of-life banknotes rich in cotton content

Many central banks are reviewing their environmentally sustainable activities, including the disposal of end-of-life banknotes, within the scope of green finance policies aimed at reducing environmental impacts. The total amount of banknote production waste and end-of-life (non-reusable) banknotes is estimated to exceed 185.000 tons per year worldwide. End-of-life banknotes are commonly disposed of as combustion, incineration for energy recovery, and landfill. In this study, the characterization and gasification of end-of-life banknotes rich in cotton content, which are classified as lignocellulosic waste, were investigated to bring them into the economy more effectively. The proximate, calorific value, lignocellulosic, elemental, and metal analyses were performed as characterization tests. Thermogravimetric analysis was performed at six different heating rates from 5 to 30 °C. The gasification experiments were carried out in a laboratory-scale fluidized bed reactor. With the gas analyzer, CO, CO2, CH4, H2, and O2 compositions as the mole fraction were determined simultaneously. The effects of temperature, particle size, and H2O/O2 ratio at the inlet intake on the experimental mole fractions were examined. The gasification main reactions that could be effective in gas composition were examined. The cotton-based banknote sample presented high levels of calorific value, C, O, H, cellulose, and lignin concentrations. The sample contained various transition metals such as Fe, Cu, Co, and Cr, which can be used as catalysts in gasification. The activation energy was calculated as 171.13 kJ/mol according to Kissinger method. In gasification experiments, the production of CO (12.11 %) and H2 (8.77 %) in a high composition was carried out.

Synergistic solvation effect and modeling of itraconazole solubility in eight binary mixtures (dichloromethane and chloroform + primary alcohol) at the range of 288.15 K to 308.15 K

In this study, the solubility and apparent thermodynamic parameters of itraconazole in chlorinated methane (dichloromethane and chloroform) + primary alcohol (methanol, ethanol, n-propanol, and n-butanol) mixtures were determined at 288.15–308.15 K utilizing the well-established shake-flask technique. The experimental mole fraction solubility of itraconazole in all studied binary solvent mixtures gradually increased as the temperature rises. Because of the synergy effect between chlorinated methane and primary alcohol mixtures, the solubility of itraconazole was maximal in chlorinated methane + primary alcohol mixtures with a 0.9 mass fraction of chlorinated methane at all tested temperatures. The solubility profile of itraconazole in chlorinated methane + primary alcohol mixtures can be explained by the synergistic effect and solubility parameters. Additionally, thermal and crystal analyses confirmed that no polymorphic transformation occurred during the dissolution processes of itraconazole. The experimental solubility of itraconazole in chlorinated methane + primary alcohol mixtures were adequately fitted and correlated with eight well-known correlation models. The modified van’t Hoff and Gibbs equations were applied to better understand and calculate the thermodynamics of itraconazole dissolved in chlorinated methane + primary alcohol mixtures. The experimental solubility and calculated solubility of itraconazole in eight binary mixtures can be helpful for drug development, such as pre-formulation study, separation, crystallization, extraction, purification, and solubilized drug formulation.

The role of water-soluble polymers on the solubility of isophthalic acid in aqueous medium: Measurements, data correlation and thermodynamic analysis

The mole fraction solubility of isophthalic acid (IPA) was measured in water and four water-soluble polymers including polyethylene glycol dimethyl ether 250 (PEGDME 250) and polyethylene glycols (PEGs) 200, 400 or PEG 600 at 293.15 K to 313.15 K along with determining the solubility of IPA in PEGDME 250 + water at the same range temperatures and also in PEGs 200, 400 or 600 + water at 298.15 K. The solubility measurements were made with the common shake-flask method under atmospheric pressure (≈ 85 kPa) in where the mass fraction of each polymer (wp) in binary mixtures was 0.0 to 1.0. At the same temperature and mass fraction of PEGDME 250, PEGs 200, 400 and 600, the upward trend for mole fraction solubility of IPA in binary mixtures was: PEG 600 + water > PEG 400 + water ≥ PEGDME 250 + water > PEG 200 + water. The experimental mole fractions of IPA were then validated and correlated using three versions of Jouyban-Acree model (Jouyban-Acree, Jouyban-Acree-van't Hoff and the modified Jouyban-Acree-van't Hoff), the modified Wilson and its combined version with the van't Hoff equation, NRTL and Wilson attaining the overall average percentage deviations (OARD) ≤ 12.7%. According to the lower value of OARD obtained from the back-correlated solubility data with the Jouyban-Acree model (6.4%) than the others, its ability in prediction of IPA solubility in the untested binary mixtures, i.e. wp = 0.1 to 0.9 with an interval 0.1 at 293.15 K, 303.15 K, 308.15 K and 313.15 K was tested and observed a good agreement between the predicted and experimental data. Finally, an endothermic and entropy-driven dissolution processes of IPA in PEGDME 250 + water was observed, in where it was only entropy-driven in wp ≥ 0.6 for PEG-based binary mixtures.

Solubility Modeling of a Bupivacaine Hydrochloride in Various Solvents over a Wide Temperature Range

In the present work, the solubility parameters of the local anesthetic drug bupivacaine hydrochloride (BH) were measured. The pure solvents under study were methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, dimethylformamide (DMF), acetic acid, and water. Two binary solvent systems, namely, methanol + water and ethanol + water, were also used to determine the solubility. The experimental solubility of the BH was obtained by the gravimetric method over a series of temperatures (293.15–333.15 K) in different mono and binary solvents under atmospheric pressure. Experimental results reveal the dependence of solubility on temperature. The experimental mole fraction solubility was further correlated with theoretical models such as the Apelblat, λh, Van’t Hoff, modified Jouyban–Acree, and CNIBS/R–K models. The small values of RAD and RMSD indicated that the data are in good agreement with experimental data. The data of solubility can be applied in the fields of production, purification, crystallization, and separation of BH.

Assessment of solid–liquid equilibrium behavior and thermodynamic analysis of natural plant extracts artemisinin (Form I) in twelve mono-solvents

Solid-liquid equilibrium solubility of artemisinin (ART) Form I in twelve mono-solvents namely N, N-dimethylformamide (DMF), oxolane (THF), n-propanol (NPA), 4-methylpentan-2-one (MIBK), ethyl formate (EF), butyl acetate (BAC), 2-ethoxyethanol (EGEE), 1,4-Dioxane, 2-methoxyethanol (EGME), 2-propoxyethanol (EGPE), propyl acetate (NPAC) and 2-butoxyethanol (EGBE) from 283.15 K to 323.15 K were determined by a laser dynamic method under 0.1 MPa. The minimum solubility of ART (Form I) was found in NPA at 283.15 K (0.004541), the maximum mole fraction solubility of ART (Form I) was observed as 0.2523 in DMF at 323.15 K. At the temperature of 298.15 K, the experimental mole fraction solubility order of ART Form I in the tested solvents was DMF (0.1559) > 1,4-Dioxane (0.09117) > THF (0.08301) > MIBK (0.05054) > EF (0.04902) > NPAC (0.03860) > BAC (0.03658) > EGME (0.02031) > EGEE (0.01859) > EGPE (0.01817) > EGBE (0.01689) > NPA (0.007185). The solubility behavior was computationally correlated by Margules model, Wilson model, NRTL model, NRTL-SAC model, Buchowski-Ksiazczak λh model and UNIQUAC model, the total RMSD was no>0.025 in the selected models. With the help of Hansen solubility parameters (HSPs) analysis, molecular similarities of ART (Form I) in twelve mono-solvents were investigated. Besides, Hirschfeld surface analysis (HSs) was considered to evaluate the intermolecular interaction of artemisinin. Moreover, thermodynamic properties including ΔmixH, ΔmixG, ΔmixS, lnγ1, lnγ1∞ of ART (Form I) in the selected solvents were estimated. All the negative ΔmixG and positive ΔmixS values indicated that the mixing process were spontaneous and entropy-increasing.

A combustion chemistry study of tetramethylethylene in a laminar premixed low-pressure hydrogen flame

The combustion chemistry of tetramethylethylene (TME) was studied in a premixed laminar low-pressure hydrogen flame by combined photoionization molecular-beam mass spectrometry (PI-MBMS) and photoelectron photoion coincidence (PEPICO) spectroscopy at the Swiss Light Source (SLS) of the Paul Scherrer Institute in Villigen, Switzerland. This hexene isomer with the chemical formula C6H12 has a special structure with only allylic CH bonds. Several combustion intermediate species were identified by their photoionization and threshold photoelectron spectra, respectively. The experimental mole fraction profiles were compared to modeling results from a recently published kinetic reaction mechanism that includes a TME sub-mechanism to describe the TME/H2 flame structure. The first stable intermediate species formed early in the flame front during the combustion of TME are 2-methyl-2-butene (C5H10) at a mass-to-charge ratio (m/z) of 70, 2,3-dimethylbutane (C6H14) at m/z 86, and 3-methyl-1,2-butadiene (C5H8) at m/z 68. Isobutene (C4H8) is also a dominant intermediate in the combustion of TME and results from consumption of 2-methyl-2-butene. In addition to these hydrocarbons, some oxygenated species are formed due to low-temperature combustion chemistry in the consumption pathway of TME under the investigated flame conditions.

Experimental Investigation of the Pressure Dependence of Iso-Octane Combustion

Iso-octane is frequently used as a surrogate fuel or as a component in primary reference fuel blends when low-temperature combustion strategies in engines are investigated. To develop control strategies for these engines, the reaction kinetics of iso-octane must be known starting from the low temperatures and intermediate pressures before ignition to the high temperatures and pressures of combustion. This work adds new experimental data sets to the validation data for reaction mechanism development by investigating the oxidation of iso-octane in stoichiometric mixtures in a flow reactor at pressures of p = 1, 10, and 20 bar and 473K ≤ T ≤ 973 K. The experimental data are compared to simulations with recent reaction mechanisms [Atef et al., Combustion and Flame 178, (2017), Bagheri et al., Combustion and Flame 212, (2020), Cai et al., Proceedings of the Combustion Institute 37, (2018), Fang et al., Combustion and Flame 214, (2020)]. The comparison between experimental and simulated mole fractions as function of temperature show reasonable agreement for all investigated pressures. In particular, the experimentally observed onset of low-temperature reactivity above a certain pressure, the shift of the negative temperature coefficient (NTC) regime with increasing pressure to higher temperatures, and the acceleration of the high-temperature chemistry are captured well in the simulations. Deviations between experimental and simulated results are discussed in detail for the reactivity of iso-octane and some key intermediates such as 2,2,4,4-tetramethyl-tetrahydrofuran, iso-butene and acetone at low temperatures.

Experimental investigation on the phase behavior of DME/ [P6,6,6,14][Cl] and thermodynamic analysis for absorption refrigeration system

Dimethyl ether (DME), as an environmental-friendly alternative refrigerant, has received broadly attention. Phosphonium-based ionic liquids with good thermophysical properties are regarded as promising absorbents in absorption refrigeration systems. In this work, the measurement of solubility behavior to DME in trihexyltetradecylphosphonium chloride ([P6,6,6,14][Cl]) was carried out from 278.15 K to 348.15 K by means of isochoric saturation method. Non-random two liquid (NRTL) model and Krichevsky-Kasarnovsky (K-K) model were used to correlate the experimental data. The absolute average relative deviation between experimental liquid mole fraction and calculated values was 0.739% and 1.517% for NRTL model and K-K model respectively. Based on the solubility results, the performance of single-effect absorption refrigeration cycle used DME/[P6,6,6,14][Cl] pairs was analyzed, and further compared with other working pairs composed of [P6,6,6,14][Cl].

Solubilities of 2,4-Dinitroanisole in Pure Organic and Mixed Organic Solvents at Temperatures between 283.15 and 313.15 K

The solubility of 2,4-dinitroanisole (DNAN) was measured in nine commonly used pure organic solvents, including ethanol, acetone, ethyl acetate, n-propanol, i-propanol, butyl alcohol, cyclohexanone, toluene, and cyclohexane, and four binary mixed solvents between 283.15 K and 313.15 K at atmosphere pressure by the gravimetric method. The solubility of DNAN showed a temperature dependence in all test solvents. The order of the solubility of DNAN was acetone ≈ cyclohexanone > ethyl acetate > n-propanol + acetone ≈ ethanol + acetone ≈ toluene > ethanol > n-propanol > water + acetone > n-butanol + acetone > n-butanol ≈ i-propanol > cyclohexane. The experimental mole fraction solubility data were correlated with the modified Apelblat equation, Yaws equation, and van’t Hoff equation. The correlation showed good agreement with the experimental results, and the largest value of the root-mean-square deviation was 11.88 × 10–4. All of the obtained results would benefit the purification and crystallization of DNAN, which would extend its applications in the field of explosives.

Phase behavior of water-menthol based deep eutectic solvent-dodecane system

In the current work, two menthol-based hydrophobic deep eutectic solvents (DESs) have been synthesized to extract dodecane from water-dodecane emulsion at 298 K and atmospheric pressure. The equilibrium mixture produces two biphasic liquid-liquid equilibrium systems and one triphasic liquid-liquid-liquid equilibrium system. 1H NMR has been used to calculate the molar composition of each phase. For both the lauric and decanoic acid-based DES, the extract phase of biphasic region-1 is rich in DES; whereas the raffinate phase is predominantly water. However, for the biphasic region-2, the extract phase is the dodecane rich phase and raffinate phase is the mixture of DES and dodecane having a dominant composition of DES. In case of triphasic region, i.e. top phase consists of dodecane and the bottom phase is only water. The middle phase becomes an emulsion where DES is the dominant component. The selectivity analysis in the triphasic region proves that both the DESs have high selectivity to extract dodecane from the water-dodecane microemulsion. The experimental mole fractions are correlated with genetic algorithm (GA) promoted NRTL and UNIQUAC models to predict the phase behavior. An average overall root means square deviation (RMSD, %) of 0.174% is observed for the biphasic region and 0.048% for the triphasic employing GA-NRTL model. GA-UNIQUAC predicts an average overall RMSD of 0.340% for biphasic regions and 0.129% for the triphasic region.

Drug Solubility and Dissolution Thermodynamic Approach in Various Solvents at Different Temperatures: A Review

In chemical science, pharmaceutical, food science, petrochemicals, and material science, the solubility parameter is one of the most important factors. The studies of solubility and thermodynamics properties are directly used in crystallization-recrystallization, purification of yields, low toxicity of solvent or green solvent, modification, and many more. The experimental mole fraction solubility of compounds may be determined by various methods such as static gravity, laser dynamic, isothermal equilibrium, shake flask, and a number of other ways. The present review is focusing on the shake flask method. Further, the experimental mole fraction solubility was correlated with a theoretical model such as the Appellate and Buchowski equations. With the help of model correlation such as the Relative Average Deviation (RAD), Absolute Relative Deviation (ARD), and Root Mean Square Deviation (RMSD) for prediction of the best model fitting in theoretical approach. The Van't Hoff equation is most effective in the prediction of the dissolution thermodynamic factors such as ∆H°(mixing enthalpy change), ∆G°(mixing Gibbs energy change), and ∆S°(mixing entropy change). It had been given consequence details about endothermic or exothermic and entropy drive, which was directly applied in industrial production and purification of the drug.

Development of Abraham model correlations for solute transfer into cyclopentanol from both water and the gas phase based on measured solubility ratios

ABSTRACT Experimental mole fraction solubilities are reported for acenaphthene, benzoin, salicylamide, o-acetoacetanisidide, benzoic acid, 4-chlorobenzoic acid, 3,4-dichlorobenzoic acid, 4-methoxybenzoic acid, 3,4-dimethoxybenzoic acid, 2-hydroxybenzoic acid, 2-methylbenzoic acid, 3-methylbenzoic acid and 4-nitrobenzoic acid dissolved in cyclopentanol at 298.15 K. Results of experimental measurements, combined with published solubility data and activity coefficient data taken from the published literature, were used to derive Abraham model correlations for solute transfer into anhydrous cyclopentanol solvent from both water and from the gas phase. The derived Abraham model correlations back-calculate the observed experimental data to within 0.11 log units (or less).

Measurement and correlation of solubility of lifitegrast in four mixtures of (diethylene glycol monoethyl ether, glycerol, PEG 400, and propylene glycol + water) from 288.15 K to 308.15 K

In this study, the solubility of lifitegrast was measured at various temperatures ranging from 288.15–308.15 K in four green solvents + water mixtures through a solid-liquid equilibrium via the shake-flask method. The experimental mole fraction solubility of lifitegrast increased with increasing temperature. The mole fraction solubility of lifitegrast increased as the mass fraction of green solvents increased at a constant temperature, except in diethylene glycol monoethyl ether (DEGME) + water mixtures. The mole fraction solubility of lifitegrast in neat polyethylene glycol 400 (PEG 400), which was approximately 33,600 times higher than in neat water at 298.15 K, was the highest solubility overall binary composition. Five models, including the van’t Hoff model, modified Apelblat model, simplified CNIBS/R-K model, Sun model, and Ma model were used to correlate and fit the experimental solubility data of lifitegrast in four green solvents + water mixtures. The thermodynamic parameters during the dissolution process of lifitegrast in four green solvents + water mixtures, such as enthalpy (ΔH°), Gibbs free energy (ΔG°), and entropy (ΔS°), were estimated using the modified van’t Hoff equation. The solubility data and correlation models could be useful for developing formulations during drug product development, such as eye drops based on these results.

Representation of Vapor-Liquid Equilibria Properties for Binary Mixtures Containing R1234ze(E) using Machine Learning Models

It is necessary to develop general and efficient models for the representation of vapor-liquid equilibria (VLE) for the binary mixtures containing R1234ze(E) which will be new alternatives to conventional refrigerants. This work investigates the applicability of four machine learning models, including K-nearest neighbor (KNN), support vector regression (SVR), random forests (RF), and multi-layer perceptron (MLP), in representing VLE for 10 binary mixtures. The accuracy, stability, computational complexity and extrapolation ability of these machine learning models are analyzed and compared with two thermodynamic models including Soave–Redlich–Kwong (SRK) and Peng–Robinson (PR). The results show the KNN, RF and MLP models are not suitable to accurately represent the experimental pressure and vapor-phase mole fraction. The SVR model is the most accurate machine learning model in representing the experimental pressure with a mean absolute relative error of 0.71%, basically as accurate as the PR and SVR models. Meanwhile, the SVR model describes the experimental vapor-phase mole fraction more accurately with a mean absolute error of 0.0049 compared to the PR and SVR models. In addition, the SVR model has a low running-time cost and a certain extent of extrapolation ability.