Models to predict solubility in ternary solvents based on sub-binary experimental data

The capability of the extended forms, of two well established cosolvency models, i.e. the combined nearly ideal binary solvent/Redlich-Kister equation and the modified Wilson model, used to predict the solute solubility in non-aqueous ternary solvent mixtures is presented. These predictions are based on the measured solubilities of anthracene in binary solvent mixtures. As a result the values of average percent deviations were less than 2% for the anthracene solubility in ternary mixtures. This work was also extended to other cosolvency models, ie. the extended Hildebrand solubility approach and the mixture response surface method, which are also commonly used for correlating solubility data in ternary solvents. The accuracy of the models is compared with each other and also with a published solubility model for ternary mixtures. The results illustrate that all models produced comparable accuracy.     

Solubility of celecoxib in carbitol + water mixtures at various temperatures: experimental data and mathematical modelling

ABSTRACT

A brief review on various solubilisation techniques of coxibs is provided and the solubility of celecoxib (CXB) in binary solvent mixtures of {carbitol (1) + water (2)} is reported at temperatures ranging from 298.2 to 313.2 K. Three cosolvency models, i.e. Yalkowsky model, Jouyban–Acree model and the Jouyban–Acree–van’t Hoff model, have been used for correlating the reported data, and the mean relative deviations are employed to evaluate the accuracy of the fitness. Solubilities are also predicted by the generally trained version of the Jouyban–Acree model and its combined model with Abraham solute parameters previously proposed for {carbitol (1) + water (2)} binary mixtures. Furthermore, the apparent thermodynamic properties of dissolution process of CXB in all -investigated solvents were calculated according to van’t Hoff and Gibbs equations.     

Determination and mathematical modelling of budesonide solubility in N-methyl-2-pyrrolidone + water mixtures from T = 293.2 to 313.2 K

The solubilities of budesonide (BDS) in binary aqueous mixtures of N-methyl-2-pyrrolidone at temperatures ranging from 293.2 to 313.2 K were determined and mathematically correlated by three cosolvency models, i.e. Jouyban–Acree model, Jouyban–Acree–van’t Hoff model and modified Wilson model. The solubilities were measured using the shake-flask method and the models wereused to fit the solubility data of BDS in the solvent mixtures. The obtained mean relative deviations (MRDs %) for cosolvency models trained using whole data points varied between 5.0% and 31.0%. Solubilities were also predicted by the generally trained version of the Jouyban–Acree model with the MRD of 37.0%. Furthermore, the apparent thermodynamic properties of dissolution process of BDS in all the mixed solvents were calculated according to van’t Hoff and Gibbs equations. Dissolution of BDS in these mixed solvents is an endothermic process.     

Solvatochromic Linear Solvation Energy Relationships (LSER) for Solubility of Gases in Various Solvents by Target Factor Analysis

A linear solvation free energy relationship has been conducted to study the effects of solvent and solute properties on the free energy of solvation of inert gases and normal alkanes in different solvents. Factor analysis combined with target factor analysis was used to identify and quantify the factors controlling the variation of free energies of solvation, without the need to postulate any priori hypothetical method. Factor analysis of the solvation data revealed that there are two factors affecting the solubility of both types of gases in non‐polar as well as polar solvents. Target testing of the solvent parameters indicated that the Hildebrand solubility parameter of solvents is the major factor controlling the solubility of gases. Moreover, it was found that the coefficient of the Hildebrand solubility parameter in the linear solvation free energy equations has linear correlation with energy of vaporization and Lennard‐Jones force parameter of inert gases and number of carbon atoms and energy of vaporization of normal alkanes.     

Solubility of budesonide in {ethanol + water} mixtures from T = (293.2 to 313.2) K: Experimental measurement and mathematical modelling

The solubility of budesonide (BDS) in binary mixtures of ethanol and water at T = (293.2–313.2) K is determined and mathematically represented using two cosolvency models, i.e. Jouyban–Acree model and Jouyban–Acree–van’t Hoff model. The mean relative deviations for fitting the solubility data of BDS in binary mixtures of ethanol + water are 6.6% and 6.5%, respectively. Furthermore, the apparent thermodynamic properties, dissolution enthalpy, dissolution entropy, and Gibbs free energy change of dissolution process of BDS in all the mixed solvents were calculated according to van’t Hoff and Gibbs equations. Dissolution of BDS in these mixed solvents is an endothermic process.     

Comparative study on the thermodynamic retention models in HPLC

Summary A series of model substances with known solubility parameter were chromatographed and from the temperature dependence of the capacity factor, some of the thermodynamic parameters influencing solute retention were determined. A linear relationship was derived between the enthalpy density and the solute solubility parameter from which a graphical method was introduced for the determination of phase characteristics.Comparing the predicted and measured capacity factor values it has been found that the predicted values are very sensitive to the literature data selected for the computation; however, by using the van der Waals molecular volume in the calculation significantly lower deviation was found from the measured data. Two equations are given for the prediction of selectivity and as the mathematical criteria of the validity of the used thermodynamic models. The results show that the predicted selectivity values are similar to the measured data using given initial parameters in the computation. However, the unreliability of the literature data makes the application of the retention models difficult.Dedicated to Professor J. F. K. Huber on the occasion of his 60th birthday.     

Solubility of Ketoconazole in Binary and Ternary Solvents of Polyethylene Glycols 200, 400 or 600 with Ethanol and Water at 298.2 K. Data Report and Analysis

The solubilities of ketoconazole in binary and ternary mixtures of water, ethanol and polyethylene glycols 200, 400 or 600 (185 data points) were determined at 298.2 K. Williams–Amidon and Jouyban–Acree cosolvency models were used to model the data, with overall mean relative deviations (OMRDs) for the solubility data in binary and ternary solvents of 17.5 and 23.5%, respectively. For predicting the solubility data of ketoconazole the trained versions of the models were used and the OMRD values were 47.7 and 33.0%, respectively.     

Solubility prediction of paracetamol in binary and ternary solvent mixtures using Jouyban-Acree model

The Jouyban-Acree model has been used to predict the solubility of paracetamol in water-ethanol-propylene glycol binary and ternary mixtures based on model constants computed using a minimum number of solubility data of the solute in water-ethanol, water-propylene glycol and ethanol-propylene glycol binary mixtures. Three data points from each binary solvent system and solubilities in neat solvents were used to calculate the binary interaction parameters of the model. Then the solubility at other binary solvent compositions as well as in a number of ternary solvents were predicted, and the mean percentage deviation (+/-S.D.) of predicted values from experimental solubilities was 7.4(+/-6.1)%.     

内压与Henry常数

建立了一个气体溶解度的新模型,它实际上是Pierotti理论的修正,按照这个模型,稀溶液中的溶质被视为虚拟的完全气体,Henry常数则是1mol完全气体的压力与一个Boltzmann因子的乘积,这个因子取决于溶质分子周围溶剂的内压。对若干气体在有机溶剂和聚合物中溶解度数据检验结果表明,这个模型能满意地用来描述Henry常数随温度的变化规律。计算得到的稀溶液形成的偏摩尔热力学函数也与实验值吻合。     

Determination and Correlation of the Solubility of Acetylpyrazine in Pure Solvents and Binary Solvent Mixtures

The solubilities of acetylpyrazine in seven pure solvents and one binary solvent mixture were determined by a dynamic analytic method at temperatures ranging from 268.15 to 308.15 K under atmospheric pressure. For pure solvents, the solubility of acetylpyrazine increases with increasing temperature and solvent polarity. For the binary solvent mixture of ethyl acetate and isopropanol, the solubility increases with increasing temperature and mole fraction of ethyl acetate. The solubility data were correlated with some thermodynamic models, including the modified Apelblat model, λh model, CNIBS/R-K model, and NRTL model. In addition, the relationship between solubility and solvent polarity was investigated by using the Arrhenius equation. All the models or equations gave satisfactory correlation results. The results showed that the solubility of acetylpyrazine generally rises with the increase of solvent polarity at the same temperature. Moreover, the dissolution thermodynamic properties of acetylpyrazine in different solvents were calculated and are discussed based on the NRTL model.     

Predicting solubility of anthracene in non-aqueous solvent mixtures using a combination of Jouyban-Acree and Abraham models

Quantitative structure property relationships were proposed to calculate the binary interaction terms of the Jouyban-Acree model using coefficients of Abraham solvational models. The applicability of the proposed methods for reproducing solubility data of anthracene in binary solvents has been evaluated using 56 solubility data sets collected from the literature. The mean percentage deviation (MPD) of experimental and calculated solubilities, using predicted mole fraction solubility of anthracene in solvents 1 and 2, has been computed as a measure of accuracy and the MPD of the proposed methods were 5.5 and 4.2%. The accuracy of the method was compared with that of a previously reported method where the MPD was 14.4% and the mean differences between proposed and previous methods was statistically significant. To provide a predictive model, solubility of anthracene was computed using Abraham solvational models and employed to predict the solubility in binary solvents using derived model constants of Jouyban-Acree model and the obtained MPDs were 37.9 and 22.2%, respectively.     

Concentration dependence of lumped mass transfer coefficients linear versus non-linear chromatography and isocratic versus gradient operation

The general rate model provides a reliable platform to predict elution bands in both linear and non-linear chromatography provided the required equilibrium functions and the coefficients quantifying the mass transfer in and around the particles are available. If further the variation of the equilibrium functions with changes in the mobile phase composition is known, this model is also able to predict gradient elution chromatography. Significant disadvantages of the model are the need to specify three kinetic coefficients and the amount of computing time required for the numerical solution of the underlying equations. Thus, several simplified models have been suggested lumping mass transfer resistances together. In this work the accuracy of predicting chromatographic bands based on the numerical solution of two lumped models has been analyzed. Elution profiles calculated by (a) the transport-dispersive and (b) the equilibrium-dispersive models were compared between each other and with the solution of the more detailed general rate model. In the analysis performed both linear and non-linear chromatography was considered under isocratic and gradient conditions.     

Solubilities of Hexaphenoxycyclotriphosphazene and Tri(2-cyanoethyl)phosphine in Selected Solvents: Measurement and Correlation

Solubilities of hexaphenoxycyclotriphosphazene and tri(2-cyanoethyl)phosphine in selected solvents were measured in this work using a static analytical method. The solubilities of a series of phosphorus-containing flame retardants in organic solvents and water were recently measured in our laboratory. Based on these data and the solid?Cliquid equilibrium equation for the solute, the activity coefficients of these flame retardants were derived in pure solvents. The Scatchard?CHildebrand activity coefficient model was used to correlate these activity coefficients and the solubility parameters of the solutes were obtained. With the help of the analysis of the solubility parameters for the solute and solvents, solubility enhancement can be achieved due to the occurrence of the synergetic effect of the mixed solvent.     

A state-specific polarizable continuum model time dependent density functional theory method for excited state calculations in solution

An effective state specific (SS) model for the inclusion of solvent effects in time dependent density functional theory (TD-DFT) computations of excited electronic states has been developed and coded in the framework of the so-called polarizable continuum model (PCM). Different relaxation time regimes can be treated thus giving access to a number of different spectroscopic properties together with solvent relaxation energies of paramount relevance in electron transfer processes. SS and conventional linear response (LR) models have been compared for two benchmark systems (coumarin 153 and formaldehyde in different solvents) and in the limiting simple case of a dipolar solute embedded in a spherical cavity. The results point out the complementarity of LR and SS approaches and the advantages of the latter model especially for polar solvents. The favorable scaling properties of PCM-TD-DFT models in both SS and LR variants and their availability in effective quantum mechanical codes pave the route for the computation of reliable spectroscopic properties of large molecules of technological and/or biological interest in their natural environments.