Binary Mixtures Of Propylene Glycol Research Articles

Solubility of atenolol in aqueous propylene glycol mixtures revisited: IKBI preferential solvation analysis

ABSTRACT The preferential solvation parameters of atenolol in aqueous binary mixtures of propylene glycol (PG) were derived from reported molar solubility values after conversion to mole fractions by using the inverse Kirkwood–Buff integrals method. This drug is sensitive to preferential solvation effects in this binary system. The preferential solvation parameter by PG (δx 1,3) is negative in water-rich mixtures but positive in mixtures of 0.20 < x 1 < 1.00. It is conjecturable that hydrophobic hydration around the non-polar methyl and phenylene groups of this drug observable in water-rich mixtures could play a relevant role in drug solvation. Otherwise, in mixtures of 0.20 < x 1 < 1.00, the preferential solvation by PG could be due to the acidic behaviour of atenolol.

MOLECULAR INTERACTION PARAMETERS THROUGH FTIR SPECTRAL ANALYSIS

Ponte Academic JournalNov 2020, Volume 76, Issue 11 MOLECULAR INTERACTION PARAMETERS THROUGH FTIR SPECTRAL ANALYSISAuthor(s): K. Srisanthi ,Sk. Suriya Shihab, K. Mallika, S. Sreehari SastrymJ. Ponte - Nov 2020 - Volume 76 - Issue 11 doi: 10.21506/j.ponte.2020.11.11 Abstract:Molecular interaction parameters and the strength of molecular interactions in the binary mixtures of Propylene glycol and Heptanol for different molar ratios are investigated through FTIR spectral data analysis. The intermolecular interaction parameters: Force constant, bond length, infrared intensity enhancement and molecular polarizability are considered in the computation. These parameters are very sensitive to the shifts in the vibrational frequencies that are caused by molecular interactions of functional groups. Propylene glycol (PG) and Heptanol for different molar ratios (PG + Heptanol: 0.1 + 0.9 to 0.9 + 0.1) that are taken for determining hydrogen bonded liquid complex systems. The results confirmed showing that the intermolecular hydrogen bond formation for molar ratio of the liquid complex 0.2 + 0.8 is stronger compared to other molar systems. Further, the observed results are correlated by the statistical analysis of FTIR data. Such statistical analysis includes the computation of variance � covariance values and eigen values using MATALAB computational tool. Download full text:Check if you have access through your login credentials or your institution Username Password

STUDY OF INTERMOLECULAR INTERACTIONS THROUGH EXCESS THERMOACOUSTIC PARAMETERS IN BINARY MIXTURES OF PROPYLENE GLYCOL AND HEXANOL FOR HEAT TRANSFER APPLICATIONS

Ponte Academic JournalMay 2020, Volume 76, Issue 5 STUDY OF INTERMOLECULAR INTERACTIONS THROUGH EXCESS THERMOACOUSTIC PARAMETERS IN BINARY MIXTURES OF PROPYLENE GLYCOL AND HEXANOL FOR HEAT TRANSFER APPLICATIONSAuthor(s): K. Srisanthi ,Sk. Suriya Shibab, S. Sreehari SastryJ. Ponte - May 2020 - Volume 76 - Issue 5 doi: 10.21506/j.ponte.2020.5.4 Abstract:The investigation on relative strength and the nature of the intermolecular interaction have been done using Ultrasonic method. In our study Density, viscosity, Ultrasonic sound velocities are estimated, further thermo acoustical parameters and their excess values such as, excess adiabatic compressibility (KsE), excess intermolecular free length (LfE),excess free volume (VfE), excess Gibb’s free energy (GE), excess enthalpy (HE) and excess internal pressure (πE) have been measured for propylene glycol in Hexanol for various mole fractions. These results have been explained on the basis of intermolecular interactions between the components in the liquid mixture and correlations among the parameters are discussed. The study indicated that intermolecular hydrogen bond formation is stronger for (0.8 PG+0.2 Hexanol) molar ratio of the binary mixture liquid complex compare to that of other concentrations and hence this mixture is strongly recommended in therapeutical drugs, pharmaceutical industry and for the high heat transferability applications. Download full text:Check if you have access through your login credentials or your institution Username Password

Mesalazine solubility in propylene glycol and water mixtures at various temperatures using a laser monitoring technique

An updated lab-made setup is used to study mesalazine solubilization behavior in the binary mixtures of propylene glycol and water at the temperature range of 293.2–313.2 K. The solubility data are correlated with some linear and non-linear cosolvency models including the van't Hoff, the mixture response surface, the Yalkowsky, the Jouyban-Acree, the Jouyban-Acree-van't Hoff, and the modified Wilson models, and the mean relative deviations (MRD%) of the predicted solubility data by the investigated models are computed. Furthermore, the apparent thermodynamics of mesalazine dissolution process is calculated by using the van't Hoff and Gibbs equations. Moreover, by using the inverse Kirkwood-Buff integrals it is apparently observed that no preferential solvation of mesalazine is present in these mixtures.

Measurement and mathematical modeling of ketoconazole solubility in propylene glycol + water mixtures at various temperatures

The aim of this work was to study the solubilization behavior and thermodynamics of ketoconazole solubility in the binary mixtures of propylene glycol (PG) and water at five different temperatures ranging T = 293.2–313.2 K. Some cosolvency mathematical models including van't Hoff equation, Yalkowsky model, Jouyban-Acree model, Jouyban-Acree-van't Hoff model, modified Jouyban-Acree-van't Hoff model, the modified Wilson model, the double log-log model and the mixture response surface model were fitted to the experimental results, and the mean relative deviations (MRD%) of the back-calculated solubilities were calculated. Density of the solutions saturated with ketoconazole over the entire solvent composition and temperature range was also determined and the obtained density values were correlated/back-calculated with the Jouyban–Acree model, resulting in a very accurate calculation of the densities with MRD% of 0.1%. Moreover, apparent thermodynamic properties of ketoconazole dissolution process in the investigated mixed solvents including entropy, enthalpy and Gibbs free energy were computed using van't Hoff and Gibbs equations. Furthermore, preferential solvation analysis demonstrates that ketoconazole is preferentially solvated by water in water-rich mixtures but preferentially solvated by PG in the other mixtures.

Experimental and computational approaches for measuring minoxidil solubility in propylene glycol + water mixtures at different temperatures

Minoxidil solubility in binary mixtures of propylene glycol + water at different temperatures has been performed by shake-flask method followed by spectrophotometry method. Four cosolvency models including the modified Wilson model, the Yalkowsky model, Jouyban-Acree model and Jouyban-Acree-van't Hoff model were used to correlate the measured solubility data. The correlation and prediction abilities of these models were compared by computing mean relative deviations (MRD%). Apparent thermodynamic properties of minoxidil dissolution such as enthalpy, entropy and Gibbs free energy were investigated through van't Hoff and Gibbs equations. Furthermore, preferential solvation parameters of minoxidil were calculated by means of the inverse Kirkwood-Buff integrals.

Solubility of bosentan in {propylene glycol + water} mixtures at various temperatures: experimental data and mathematical modelling

ABSTRACTSolubility measurements were performed for bosentan (BST) in binary mixtures of propylene glycol (PG) and water at atmospheric pressure within the temperature range, T = 293.2 – 313.2 K by employing a shake-flask method. Generated solubility data were correlated with Jouyban-Acree-van’t Hoff model and the accuracies of the predicted solubilities and model performance were illustrated by mean relative deviations (MRD). Furthermore, the apparent thermodynamic properties of BST dissolving in all the mixed solvents were calculated, and the obtained results show that the dissolution process is endothermic. By using the inverse Kirkwood–Buff integrals, it was observed that BST is preferentially solvated by water in water-rich solvent mixtures and preferentially solvated by PG (as a cosolvent) in the composition range of 0.20 < x1 < 1.00 at 298.2 K.

Flow behaviour of suspensions of functionalized graphene nanoplatelets in propylene glycol–water mixtures

The low thermal conductivity of the fluids usually used in heat exchange processes (water, oils, glycols…) has proved to be one of the limiting factors in improving their heat transfer performance. These traditional fluids enhance their thermal capabilities by dispersing nano-sized particles with high thermal conductivity, as many researches have revealed in the last decades. Although the thermal conductivity of nanofluids has centred the interest of the heat transfer community, the rheological behaviour of the resulting dispersions is very influential in the heat transfer process, pressure drops and pumping powers. In this work, different samples of functionalized graphene nanoplatelets dispersed into two different binary mixtures of propylene glycol and water at 10:90wt% and 30:70wt% have been analysed by using a DHR-2 rotational rheometer equipped with concentric cylinder geometry. Firstly, the flow curves for Krytox GPL102 oil, pure propylene glycol, and the two binary mixtures of propylene glycol and water used as base fluids were experimentally obtained. These values were used to check our experimental procedure finding a good agreement between them and those reported and well known in the literature, with an absolute average deviation of 2.0%. Then, the viscosity-shear rate curves in the temperature range from 278.15 to 323.15K were obtained for the different graphene nanofluid sets. Furthermore, a new equation was proposed in this work to describe the viscosity dependence on both the temperature and the nanoparticles volume concentration of graphene nanoplatelet nanofluids with an absolute average deviation with respect to our experimental data lower than 2%. Additionally, oscillatory tests of the samples were performed observing pseudoplastic behaviour for the nanofluids at lower angular frequencies.

Ultrasonic, Density and Viscosity Studies in Binary Mixtures of Propylene Glycol and 1-Pentanol at Room Temperature

Ultrasonic, Density and Viscosity Studies in Binary Mixtures of Propylene Glycol and 1-Pentanol at Room Temperature

Modeling, solubility, and thermodynamic aspects of sodium phenytoin in propylene glycol–water mixtures

The solubility of sodium phenytoin in binary mixtures of propylene glycol and water at 298.2, 303.2, 308.2, and 313.2K was measured. The effect of solvent composition on the thermodynamic properties of the dissolution process, including enthalpy, entropy, and Gibbs energy were studied based on van't Hoff analysis and the Gibbs equation. Experimental solubility was determined using the shake-flask method and the resulting data were correlated with the Jouyban–Acree model and with the Jouyban–Acree model in combination with the van't Hoff equation.

Solubility of Sodium Phenytoin in Propylene Glycol + Water Mixtures in the Presence of B-Cyclodextrin

Poor aqueous solubility of drugs is still a challenging aspect in drug discovery and development. Solubilization techniques such as cosolvency and complexation are used to solubilize poorly soluble drugs. A number of mathematical models presented for predicting the solubility of drugs in water+cosolvent mixtures and the Jouyban-Acree model promises more accuracy when compared with other algorithms. Methods: Solubility of sodium phenytoin in binary mixtures of propylene glycol + water in the presence of beta-cyclodextrin (b-CD) along with the solubility of sodium phenytoin in this solvent mixture in the absence of b-CD using saturating shake flask method were studied. The generated solubility data was fitted to the Jouyban-Acree model and the solubility profile of drug in the presence of b-CD was compared with solubility data in the absence of b-CD. Results: The solubility was increased by addition of propylene glycol and was decreased by addition of beta-cyclodextrin. The measured solubility data were used to evaluate the correlation ability of the Jouyban-Acree model employing the solubility data in monosolvent. These findings are supported by acceptable mean relative deviations values obtained when comparing the estimated and experimental solubilities. Conclusion: The addition of b-CD was decreased the solubilization power of propylene glycol.

Solubility and saturation apparent specific volume of some sodium sulfonamides in propylene glycol + water mixtures at 298.15 K

Equilibrium solubility of sodium sulfadiazine (Na.SDZ), sodium sulfamerazine (Na.SMR), and sodium sulfamethazine (Na.SMT), was determined in aqueous binary mixtures of propylene glycol (PG) at 298.15K. If the solubility values expressed in both concentration scales are considered, i.e. mole fraction and molarity, in water-rich mixtures the solubility decrease as: Na.SDZ>Na.SMT>Na.SMR, whereas, in PG-rich mixtures the observed order is: Na.SMT>Na.SDZ>Na.SMR. In all cases the solubility in neat water is higher than those in neat PG. Correlation of the solubility data obtained was made by means of the Jouyban–Acree model for all the sodium sulfonamides. Otherwise, apparent specific volumes (ϕVsp) of sodium sulfonamides at saturation were also calculated in all the mixtures. The average ϕVsp values are as follows: 0.663cm3g−1 for Na.SDZ, 0.723cm3g−1 for Na.SMR, and 0.740cm3g−1 for Na.SMT, with a variation lower than 5.0% in each case.

Thermodynamic solubility of piroxicam in propylene glycol + water mixtures at 298.2-323.2 K: Data report and modeling

The solubility of piroxicam (66 data points) in binary mixtures of propylene glycol (PG) + water at six different temperatures which ranged from 298.2 K to 323.2 K were reported. Three different cosolvency models; Yalkowsky, Jouyban-Acree and combined version of the Jouyban-Acree model with van?t Hoff approach, have been used for correlating the reported data. All the analyses results show the acceptable range of the error percentages.

Solubility of three basic drugs in propylene glycol + water mixtures in the presence of β-cyclodextrin

Cosolvency and complex formation are the important methods to increase the solubility of drugs. These methods can be used to change solubility simultaneously. In this study, solubilities of three basic drugs, i.e. atenolol, diazepam and lamotrigine, were studied in binary mixtures of propylene glycol + water in the presence of cyclodextrin (CD) and atenolol in this solvent mixture in the absence of CD using saturating shake flask method. The generated solubility data was fitted to the Jouyban-Acree model and the solubility profile of each drug was compared with solubility data in the absence of CD that the solubility data of diazepam and lamotrigine taken from the literature.

Thermodynamic studies of fluphenazine decanoate solubility in propylene glycol + water mixtures and correlation with the Jouyban–Acree model

Solubilities of fluphenazine decanoate (FD) in binary mixtures of propylene glycol + water (PG + W) at 293.2, 298.2, 303.2, 308.2, and 313.2 K are reported. The combination of Jouyban–Acree model and van’t Hoff equation is used to predict the solubility of FD in a given solvent mixture at different temperatures. The thermodynamic properties (enthalpy, entropy and Gibbs energy standard changes of solutions) for FD in PG + W mixtures are calculated from solubility data using the modified version of van’t Hoff and Gibbs equations. The results show that Jouyban–Acree model can predict the solubility of FD in PG + W mixtures as a function of temperature over the studied temperature range. The study represents the first time that thermodynamic properties of solutes dissolved in binary solvent mixtures have been described by the Jouyban–Acree model. The calculated values are in good agreement with the measured experimental data.

Anomalous Component Dynamics of a Binary Mixture of Associating Glass-Forming Liquids

The binary mixtures of propylene glycol (PG) with 2-ethylhexylamine (EHA) show changes of the dynamics of the higher-T(g) component PG on increasing the concentration of the lower T(g) component EHA very different or even opposite in trend from those found in other associating and nonassociating binary mixtures. For example, the fragility index m increases and the coupling parameter n of the PG component increases on adding EHA, while T(g) of the PG component does not change up to 0.5 molar fraction of EHA. From the features present in the broadband dielectric spectra of the PG component at different compositions, the anomalies are identified to originate from the enhancement of intermolecular coupling in the primary relaxation of the higher-T(g) PG component by the presence of the EHA component. The enhancement can be traced to the fact that neat EHA has larger intermolecular coupling than neat PG, despite the former having a lower T(g) than the latter. The enhancement of intermolecular coupling of the PG component increases on increasing the concentration of EHA in the mixture, as evidenced by the appearance of the JG β-relaxation of the PG component well separated from the α-relaxation when the molar fraction of EHA has been increased to 0.75. In contrast, the JG β-relaxation of neat PG is too close to the α-relaxation and cannot be resolved. The anomalous dynamics of PG in the mixtures is challenging to all theories and models of glass transition to explain. The insight gained on the physical origin of the anomalous dynamics leads to a rationalization in the framework of the coupling model.

Vehicle Composition Influence on the Microneedle-Enhanced Transdermal Flux of Naltrexone Hydrochloride

Transdermal delivery of drugs is often limited by formidable barrier properties of stratum corneum (SC). Microneedles (MN) enable creation of transient microchannels in the SC and bypass this barrier. Many reports have focused on the great effectiveness of MN in improving percutaneous flux values of a variety of drugs over a large molecular size spectrum. The objective of the present study is to evaluate the influence of formulation on MN-enhanced transdermal transport of naltrexone hydrochloride (NTX HCl). A series of in vitro experiments employing binary mixtures of propylene glycol (PG) and water as vehicle were used with either MN-treated or untreated skin. A simple model taking into account two parallel flux values through intact skin and microchannels was used to analyze data. Transdermal permeation of NTX HCl from different donor solutions indicated that PG-rich formulations greatly limited MN-enhanced transport but had a much smaller effect on transport through intact skin. Diffusion through the microchannel pathway seems to be donor viscosity-related and follows the relationship predicted by the Stokes-Einstein equation as shown by linear dependence of flux on diffusivity of NTX in donor solutions.