Molar Solubility Research Articles

Solubility of Etoricoxib in Aqueous Solutions of 1,4-Butanediol, 1,4-Dioxane, N,N-Dimethylacetamide, N,N-Dimethylformamide, Dimethyl Sulfoxide, and Ethanol at 298.2 K

Models for predicting the solubility of drugs in monosolvents and their mixtures have a practical importance in design and development of new products in pharmaceutical industries. Thus, present investigation pertains to the utility of a correlative model for solubility prediction of etoricoxib (ETR). The molar solubilities of ETR in a number of monosolvents and various mass fractions of their binary aqueous solvent mixtures were determined using the shake-flask method at 298.2 K. Densities of ETR saturated solutions in the monosolvents and their binary solvent mixtures were measured and then correlated using a well-established method proposed by Jouyban and Acree. Overall mean percentage deviations (OMPDs) between experimental and predicted values were 3.4 % for the molar solubilities and 0.1 % for the densities of the saturated solutions.

Abraham model correlations for describing solute transfer into 2-butoxyethanol from both water and the gas phase at 298 K

Infinite dilution activity coefficients (γ∞) were measured at 298K for 12 different aliphatic hydrocarbons (alkanes, cycloalkanes, alkenes), 11 different aromatic compounds (benzene, alkylbenzenes, halobenzenes, naphthalene), and 2-chloro-2-methylpropane dissolved in 2-butoxyethanol at 298K using a headspace gas chromatographic method. As part of the experimental study solubilities of 19 crystalline nonelectrolyte solutes (2-hydroxybenzoic acid, acetylsalicylic acid, 3,5-dinitro-2-methylbenzoic acid, acenaphthene, trans-stilbene, xanthene, phenothiazine, 3,5-dinitrobenzoic acid, 3-chlorobenzoic acid, 2-methylbenzoic acid, 4-chloro-3-nitrobenzoic acid, 2-chloro-5-nitrobenzoic acid, benzoic acid, 4-aminobenzoic acid, benzil, thioxanthen-9-one, 3-nitrobenzoic acid, fluoranthene, and diphenyl sulfone) were determined in 2-butoxyethanol at 298K using a static, spectrophotometric method. The experimental values were converted to gas-to-2-butoxyethanol and water-to-2-butoxyethanol partition coefficients, and molar solubility ratios using standard thermodynamic relationships. Abraham model correlations for solute transfer into 2-butoxyethanol were derived from the calculated partition coefficients and solubility ratios. The derived Abraham model describes the observed partition coefficient and solubility data to within 0.14logunits (or less).

Solubility and diffusivity of liquids for food and pharmaceutical applications in crosslinked polydimethylsiloxane (PDMS) films: I. Experimental data on pure organic components and vegetable oil

The solubility and diffusivity of several liquid species in crosslinked polydimethylsiloxane (PDMS) films were determined with a gravimetric method at 35°C. The series of liquids considered includes alkanes (from n-C5 to n-C18; cyclo-C6), water, acetone, alcohols (ethanol, 1-propanol, 1-butanol, iso-butanol, tert-butanol, 1-pentanol, 1-hexanol), terpenes (squalene, limonene, linalool, geraniol) and edible oils with different oleic acid contents. The effect of size, structure and solubility parameter of the different molecules on the sorption and transport properties in PDMS was discussed. The diffusivity values of the different penetrants inspected span over one decade while the molar solubility spans over four decades, indicating that the membrane selective behavior is a strong function of liquid solubility. In particular, the solubility of hydrocarbons (alkanes, hydrocarbon terpenes) that have favorable energetic interactions with the polymer is entropy-driven, i.e. decreases with molecule size. The solubility of substances bearing one alcoholic group is also strongly affected by the energetic interactions with the polymer, especially if their alkyl chain length is small. The trends are due to the dual entropic/enthalpic nature of solubility, which obeys a nice exponential decreasing trend when reported versus the product MW0.75 (δ−δPDMS)2 which accounts for both entropic and energetic nonideality of the polymer–penetrant mixture. The diffusivity decreases roughly monotonically with the molecular size of the penetrant within a series of homologous penetrants, unless the penetrants have very high solubility differences and induce different swelling in the polymer matrix. Solubility data are well represented by the Flory−Rehner model, that also allows to explain differences between experimental sources based on the crosslinking degree.

Abraham model correlations for solute transfer into 2-ethoxyethanol from water and from the gas phase

Infinite dilution activity coefficients (γ∞) were measured at 298K for 13 different aliphatic hydrocarbons (alkanes, cycloalkanes, alkenes), 12 different aromatic compounds (benzene, alkylbenzenes, halobenzenes, naphthalene), and 2-chloro-2-methylpropane dissolved in 2-ethoxyethanol, along with solubilities for 11 crystalline organic compounds (xanthene, phenothiazine, acenaphthene, diphenyl sulfone, 3,5-dinitro-2-methylbenzoic acid, 3-chlorobenzoic acid, 2-methylbenzoic acid, 4-chloro-3-nitrobenzoic acid, 3,5-dinitrobenzoic acid, benzil, and thioxanthen-9-one) dissolved in 2-ethoxyethanol at 298K. The experimental values were converted to gas-to-2-ethoxyethanol partition coefficients, water-to-2-ethoxyethanol partition coefficients, and molar solubility ratios using standard thermodynamic relationships. The calculated partition coefficient data and molar solubility ratios, combined with published literature values, were used to derive Abraham model correlations for solute transfer into 2-ethoxyethanol from both water and the gas phase. The derived Abraham model correlations predicted the observed values to within 0.15 log units (or less).

過渡応答法による超臨界流体中の化合物の拡散係数の測定および溶解度と部分モル体積の推算

過渡応答法による超臨界流体中の化合物の拡散係数の測定および溶解度と部分モル体積の推算

Molecular dynamics simulation of the molar volumes and solubility parameters of straight alkanes

The straight chain n-alkanes used as core materials to fabricate nanoencapsulated and microencapsulated phase change of materials (PCM) have received much attention in recent years. The dissipative particle dynamics (DPD) simulation method has been emerged to investigate the encapsulated PCM from the perspective of mesoscopic. To obtain the Flory–Huggins and repulsion parameters, which is essential for the DPD study, the molar volume and solubility parameter of straight alkanes are investigated by using molecular dynamics (MD) simulation. The results showed that a linear relationship of molar volume (V) with carbon atom number (n) and simulation temperature (T) can be obtained as: V = -31.73 + 0.26T + 14.82n. A nonlinear relationship of solubility parameter (δ) with carbon atom number and simulation temperature can be described as: δ = 18.45-3.66 ×10-2n + 1.07T - 1.20 ×10-5n2- 9.60 ×10-2T2- 2.49 ×10-3nT. The equations can be used as a reference for the further DPD simulation in n-alkanes based PCM system.

Hydrocarbon molar water solubility predicts NMDA vs. GABAA receptor modulation.

BackgroundMany anesthetics modulate 3-transmembrane (such as NMDA) and 4-transmembrane (such as GABAA) receptors. Clinical and experimental anesthetics exhibiting receptor family specificity often have low water solubility. We hypothesized that the molar water solubility of a hydrocarbon could be used to predict receptor modulation in vitro.MethodsGABAA (α1β2γ2s) or NMDA (NR1/NR2A) receptors were expressed in oocytes and studied using standard two-electrode voltage clamp techniques. Hydrocarbons from 14 different organic functional groups were studied at saturated concentrations, and compounds within each group differed only by the carbon number at the ω-position or within a saturated ring. An effect on GABAA or NMDA receptors was defined as a 10% or greater reversible current change from baseline that was statistically different from zero.ResultsHydrocarbon moieties potentiated GABAA and inhibited NMDA receptor currents with at least some members from each functional group modulating both receptor types. A water solubility cut-off for NMDA receptors occurred at 1.1 mM with a 95% CI = 0.45 to 2.8 mM. NMDA receptor cut-off effects were not well correlated with hydrocarbon chain length or molecular volume. No cut-off was observed for GABAA receptors within the solubility range of hydrocarbons studied.ConclusionsHydrocarbon modulation of NMDA receptor function exhibits a molar water solubility cut-off. Differences between unrelated receptor cut-off values suggest that the number, affinity, or efficacy of protein-hydrocarbon interactions at these sites likely differ.

Nitric acid adduct formation during crystallization of barium and strontium nitrates and their co-precipitation from nitric acid media

The molar solubilities of Ba, Sr and Pb nitrates in nitric acid as a function of total nitrate concentration is presented and described by the mass action law, indicating on formation of the adducts with nitric acid. Precipitates of Ba(NO3)2 and Sr(NO3)2 crystallized from nitric acid were studied by ISP OES and IR spectroscopy. The data obtained confirmed formation of metastable adducts with nitric acid. IR and X-ray diffraction studies of the mixed salt systems indicated conversion of the mixed salts into (Ba,Sr)(NO3)2 solid solution of discrete structure in range of total nitrate ion concentration ~6 mol/L.

Abraham model correlations for solute transfer into tributyl phosphate from both water and the gas phase

Solubilities are reported for acenaphthene, fluoranthene, benzil, 9-fluorenone, trans-stilbene, phenothiazine, 2-methylbenzoic acid, 3-methylbenzoic acid, 4-chlorobenzoic acid, 3-nitrobenzoic acid, 4-nitrobenzoic acid, 3,4-dichlorobenzoic acid, 3,5-dinitrobenzoic acid, 2-chloro-5-nitrobenzoic acid, and 4-chloro-3-nitrobenzoic acid dissolved in tributyl phosphate at 298 K. The experimental solubility data, combined with published infinite dilution activity coefficients and Henry’s law constants, are used to derive Abraham model correlations for predicting molar solubility ratios, gas-to-liquid partition coefficients, and water-to-liquid partition coefficients of organic solutes and inorganic gases dissolved in tributyl phosphate. The derived Abraham model equations describe the measured experimental values to within 0.15 log units or less.

Solubility and solution thermodynamics of flofenicol in binary PEG 400 + water systems

The solubility of florfenicol in PEG 400+water solvent mixture was measured at seven temperatures from 293.15K to 316.25K. The modified Apelblat equation the General Single model and the Hybrid model were used to fit the experimental solubility data. The thermodynamic functions were obtained from the combination of the modified van’t Hoff equation with the modified Apelblat model, including standard enthalpy, entropy and Gibbs energy change of solution. Results showed that: the mole solubility of florfenicol in binary PEG 400+water solvent mixture increased with the increasing temperature and the mole fraction of PEG 400; the overall mean percentage deviation (OMPD) obtained from the modified Apelblat equation, the General Single model and the Hybrid model were 3.22, 3.73, 6.52, respectively. Thus, the modified Apelblat equation can give further accuracy and reliability of the solubility of florfenicol in the selected solvent systems than the other two fitted models. The solution process for florfenicol was always endothermic and the driving mechanism was mainly classified as the following three kinds in the temperature range from 293.15K to 316.25K: entropy-driving (from 0.0000 to 0.0064 in mole fraction of PEG 400), enthalpy and entropy driving (from 0.0064 to 0.0138 in mole fraction of PEG 400), enthalpy driving (from 0.0138 to 0.0458 in mole fraction of PEG 400).

Effects of fluorine on the solubilities of Nb, Ta, Zr and Hf minerals in highly fluxed water-saturated haplogranitic melts

The effect of fluorine on the solubilities of Mn-columbite (MnNb2O6), Mn-tantalite (MnTa2O6), zircon (ZrSiO4) and hafnon (HfSiO4) were determined in highly fluxed, water-saturated haplogranitic melts at 800 to 1000°C and 2kbar. The melt composition corresponds to the intersection of the granite minimum with the albite–orthoclase tieline (Ab72Or28) in the quartz–albite–orthoclase system (Q–Ab–Or), which is representative of a highly fluxed melt, from which high field strength element minerals may crystallize. The melt contains 1.7wt.% P2O5, 1.05wt.% Li2O and 1.83wt.% B2O3. The main purpose of this study is to examine the effect of F on columbite, tantalite, zircon and hafnon solubility for a melt with this composition. Up to 6wt.% fluorine was added as AgF in order to keep the aluminum saturation index (ASI, molar Al/[Na+K]) of the melt constant. In an additional experiment F was added as AlF3 to make a glass peraluminous. The nominal ASI of the melts are close to 1 for the minimum composition and approximately 1.32 in peraluminous glasses, but if Li is considered as an alkali, the molar ratio Al/[Na+K+Li] of the melts are alkaline (0.87) and subaluminous (1.09), respectively.The molar solubility products [MnO]∗[Nb2O5] and [MnO]∗[Ta2O5] are nearly independent of the F content of the melt, at approximately 18.19±1.2 and 43.65±2.5×10−4 (mol2/kg2), respectively for the minimum composition. By contrast, there is a positive dependence of zircon and hafnon solubilities on the fluorine content in the minimum composition, which increases from 2.03±0.03×10−4 (mol/kg) ZrO2 and 4.04±0.2×10−4 (mol/kg) HfO2 for melts with 0wt.%F to 3.81±0.3×10−4 (mol/kg) ZrO2 and 6.18±0.04×10−4 (mol/kg) HfO2 for melts with 8wt.%F. Comparison of the data from this work and previous studies indicates that ASI of the melt seems to have a stronger effect than the contents of fluxing elements in the melt and the overall conclusion is that fluorine is less important (relative to melt compositions) than previously thought for the control on the behavior of high field strength elements in highly evolved granitic melts. Moreover, this study confirms that although Nb, Ta, Zr and Hf are all high field strength elements, Nb–Ta and Zr–Hf are complexed differently in the melt.

Thermodynamic Parameters for Solvation of Nano ZNO and Its Dopes In 50% DMSO - 50% DMF (V/V) Solutions at Different Temperatures

The molal solubility for nano zinc oxide (ZnO) , copper (2%) doped ZnO , Fe(2%) doped ZnO , Ti(2%) doped ZnO , Ag (25) doped ZnO in 50%DMF and 50% DMSO, (v/v), volume to volume were measured at 293.15, 303.15 , 313.15, 323.15K . The thermodynamic parameters, Gibbs free energy of solvation, enthalpies and entropies of solvation were evaluated for nano zinc oxide and nano zinc oxide doped from the solubility measurements. These thermodynamic parameters explain the effect of doping elements on the thermodynamic behviours of nano zinc oxide in solvation process.

Solubility of clonazepam and diazepam in binary and ternary mixtures of polyethylene glycols 400 or 600, propylene glycol and water at 298.2K - experimental data and modeling

Experimental molar solubilities of clonazepam and diazepam in binary and ternary mixtures of polyethylene glycols (PEGs) 400 or 600, propylene glycol (PG) and water (138 data points) along with the density of the saturated solutions at 298.2K were reported. The Jouyban-Acree model was used to fit to the measurements for providing a computational method. Employing the solubilities in the mono-solvents, the measured solubilities in mixed solvents were back-calculated and the overall mean percentage deviations (OMPDs) of the model were 16.0 % and 19.2% for diazepam and clonazepam, respectively. Addition of the Hansen solubility parameters to the model helps us to train all the data sets (clonazepam and diazepam) at once and the back-calculated OMPD for this analysis was 19.3%.

Solubility of Sodium Acetate in Binary Mixtures of Methanol, 1-Propanol, Acetonitrile, and Water at 298.2 K

The molar solubility of sodium acetate was measured in binary mixtures of methanol, 1-propanol, acetonitrile, and water along with the density of their saturated solutions at 298.2 K. The molar solubilities span a range of nearly 4 orders of magnitude from 5.53 mol·L–1 in water to 0.0014 mol·L–1 in acetonitrile, the according values for the mole fraction solubilities are 0.119 and 0.00007. For the calculation of the solubility and the density at any composition of the binary solvent mixture, a computational method is provided, based on the Jouyban–Acree model. The method uses the solubility data in the monosolvents and their density and model constants; the latter are derived by fitting the experimental data to the Jouyban–Acree model. Solubilities and densities were back-calculated, and the overall mean percentage deviations between experimental and calculated values were 9.8 % for the solubilities and 0.4 % for the densities of the saturated solutions.

Models for the Biodegradation Kinetics of Naphthalene by Ralstonia Eutropha

Biodegradation of naphthalene (naph.) by a pure culture of Ralstonia eutropha was studied. Dissolution of naph. in aqueous solution was provided by using Tween-80 nonionic surfactant. By developing the solubility curve, the molar solubility ratio (MSR) was determined (0.8081). The effects of Tween-80, initial-pH, and naph. concentration on the R. eutropha growth and its naph. degradation capability were investigated. Degradation of naph. at 50 mg/L was complete within 52 h in the presence of 1.6 mM Tween-80 at pH 7. Haldane, Webb, Aiba, and Edwards, as the growth inhibitory kinetic models, were used to mathematically describe the inhibitory characteristic of naphthalene and the results were evaluated using nonlinear regression technique. The values of root mean square error (RMSE) and the correlation coefficient (R2) showed appropriateness of approach taken in the present study (RMSE≈ 3×10−3, R2≈ 0.99). Importance of the mechanistic view of these types of mathematical models has been emphasized.

Measurement and correlation of the solubility of florfenicol in binary 1,2-propanediol + water mixtures from 293.15 K to 316.25 K

The solubility of florfenicol in mixed 1,2-propanediol+water solvents was measured by a static analytical method at the temperature ranging from 293.15K to 316.25K. The experimental solubility data was correlated by the modified Apelblat equation, the General Single model and the Hybrid model. The results show that: the mole solubility of florfenicol in binary 1,2-propanediol+water mixtures increased with increasing temperature and the mole fraction of 1,2-propanediol in the binary solvent system; the values of the solubility calculated by the three models show good agreement with the experimental value; the OMPD from the modified Apelblat equation, the General Single model and the Hybrid model are 2.48, 2.07 and 5.12, respectively. However, compared to the modified Apelblat equation and the Hybrid model, the General Single model can give more accuracy and reliability of the solubility data. In addition, the discussion of the enthalpy and the entropy for florfenicol in different cosolvents indicated that the dissolution process of florfenicol was endothermic and entropy-driven.

Predicting the Octanol Solubility of Organic Compounds

The molar octanol solubility of an organic nonelectrolytes can be reasonably predicted solely from its melting point provided that its liquid (or a hypothetical super-cooled liquid) form is miscible with octanol. The aim of this work is to develop criteria to determine if the real or hypothetical liquid form of a given compound will be miscible with octanol based on its molar volume and solubility parameter. Fortunately, most organic compounds (including most drugs) conform to the criteria for complete liquid miscibility, and therefore have solubilities that are proportional to their melting points. The results show that more than 95% of the octanol solubilities studied are predicted with an error of less than 1 logarithmic unit.

Study on Syntheses and Anticoagulant Action of Rare Earth Ternary Complexes with Tryptophan and Sodium Citrate

Three new rare earth ternary complexes (NdLL'•4H2O, EuLL'•4H2O and LaLL'•4H2O) have been prepared with rare earth nitrates, tryptophan (L) and sodium citrate (NaL'). The characteristics of the complexes were identified by elemental analysis, IR, molar conductivity solubility and TG-DTA. The results showed the complexes have constant composition of RELL'•4H2O. And all of the rare earth ternary complexes have anticoagulant action.

SOLVATION PARAMETERS FOR SODIUM OXALATE IN MIXED ETHANOL-WATER SOLVENTS AT 301.15 K

The molar solubility of sodium oxalate (Na 2 Ox) in mixed ethanol (EtOH) – water solvent mixtures were measured at 301.15 K. From the molar solubilities, the activity coefficients, solubility products, free energies of solvation and the transfer free energies for the interaction of (Na 2 Ox) in mixed (EtOH-H 2 O) solvents were evaluated.

Solubility of Clonazepam and Diazepam in Polyethylene Glycol 200, Propylene Glycol, N-Methyl Pyrrolidone, Ethanol, and Water at (298.2 to 318.2) K and in Binary and Ternary Mixtures of Polyethylene Glycol 200, Propylene Glycol, and Water at 298.2 K

Experimental molar solubility of clonazepam and diazepam in binary and ternary mixtures of polyethylene glycol 200 (PEG 200), propylene glycol (PG), and water (116 data points) along with the density of saturated solutions at 298.2 K were reported. Also, the experimental solubilities of clonazepam and diazepam in the monosolvents of PEG 200, PG, N-methyl pyrrolidone (NMP), ethanol (EtOH), and water at five different temperatures, (298.2, 303.2, 308.2, 313.2, and 318.2) K (50 data points), have been reported. The Jouyban–Acree model was used to fit to the measurements for providing a computational method. Employing the solubilities in the neat solvents, the measured solubilities were back-calculated, and the overall mean percentage deviations (OMPDs) of the model were 21.4 % and 19.5 % for clonazepam and diazepam, respectively. An addition of the Hansen solubility parameters to the model helps us to train all of the data sets (clonazepam and diazepam) at once, and the back-calculated OMPD was 20.7 %.