Partial Molar Volumes Of Transfer Research Articles

Effect of ethylene glycol/diethylene glycol/triethylene glycol on the thermodynamics of the aqueous biotin solutions at various temperatures

Acoustic and volumetric parameters for the liquid mixture (water + Biotin + ethylene glycol/diethylene glycol/triethylene glycol) are evaluated at different temperatures (288.15 K, 298.15 K, 308.15 K, and 318.15 K) and constant pressure of 0.1 MPa over the range of biotin concentrations (0.0000, 0.0015, 0.0025, and 0.0035) mol·Kg-1. The experimental work was carried out by Anton Paar DSA 5000 M, where the density (ρ) and the speed of sound (c) are measured, which are later used to determine the various derived thermodynamic properties, such as, apparent molar properties (apparent molar volume, Vϕ; apparent molar isentropic compression,Kϕ,S), the partial molar properties (partial molar volume, Vϕ0; partial molar isentropic compression, Kϕ,S0), the partial molar transfer properties (partial molar volume of transfer, ΔVϕ0; partial molar isentropic compression of transfer, ΔKϕ,S0) and the partial molar expansibility (Eϕ0) along with its first derivative ∂Eϕ0/∂TP. The obtained results are explained in terms of the kind of intermolecular interactions developed in the mixture using the co-sphere overlap model. Further, with the partial molar properties, the pair and triplet interaction coefficients (VAB,KAB; VABB, KABB) are calculated.

Volumetric Properties of aqueous solutions of Arabinose, Xylose and Galactose in presence / absence of Sodium Cyclamate

Sugars can affect our blood glucose (sugar), weight and blood fats. Synthetic sugars (artificial sweetener) provide little or no calories or carbohydrate or do not increase blood sugar. In food and pharmaceutical industries, blends of sweeteners are commonly used to design the food products and pharmaceutical doses, the information regarding type and extent of sweetener-sweetener and sweetener -water interactions and taste quality of the solution required. The aqueous solutions of arabinose, xylose and galactose with and without cyclamate are studied. Densities of solutions of arabinose, xylose and galactose in presence of 0.05, 0.15 and 0.3 m sodium cyclamate have been measured at 298.15K. Partial molar volumes, apparent specific volumes, partial molar volumes of transfer and doublet and triplet interaction parameters have been calculated. The information obtained from these parameters has been used to understand type and extent of sweetener-sweetener and sweetener -water interactions and taste quality of the solution.

Molecular complexes of polar basic amino acids (l-lysine, l-histidine) with nicotinic acid in water and buffer solution: A thermodynamic aspects

Interactions of the polar basic amino acids, l-lysine (Lys) and l-histidine (His), with heterocyclic ligand, nicotinic acid (NA), in pure water and in phosphate buffer solution (pH 7.4) were studied by calorimetry and densimetry. Under the experimental conditions chosen, thermodynamic parameters of complex formation (lgKc, ΔcG, ΔcH, ΔcS) as well as the hydration enthalpies of different ionized forms of amino acids have been calculated at 298.15 K. The stoichiometry of complexes between Lys/His and NA was determined. The affinity of Lys to binding with NA decreases with increasing pH, the association process being less favorable. The more efficient stabilization of complexes between His and NA was exhibited in buffer media than in water. The apparent molar volumes, partial molar volumes and partial molar volume of transfer of NA from pure solvent (water/buffer) to mixed amino acid solution at infinite dilution have been evaluated. Their values obtained are lower for aqueous solutions than buffer systems. The dependence of thermodynamic characteristics obtained on molecular structure, ionization and hydration state of the solutes was analyzed. The dominant types of driving forces in the complex formation process of polar basic amino acids (Lys, His) with nicotinic acid were found for water and buffer solution.

Temperature-dependent thermodynamic and physicochemical studies of glycols in aqueous biotin solutions

The current study deals with the analysis of the molecular interactions among the glycols (propylene glycol, PG and hexylene glycol, HG) molecules in (0.000, 0.001, 0.002 and 0.003) mol·Kg-1 aqueous solutions of biotin at constant experimental pressure 0.1 MPa and temperature range (288.15 K, 298.15 K, 308.15 K and 318.15 K). The speed of sound and the density for the liquid mixtures is measured with Anton Paar DSA 5000 M. Numerous thermodynamic and acoustic parameters are determined using these experimental data. The apparent molar volume (Vϕ), partial molar volume (Vϕ0), partial molar volume of transfer (ΔVϕ0), apparent molar isentropic compression (Kϕ,S), partial molar isentropic compression (Kϕ,S0), partial molar isentropic compression of transfer (ΔKϕ,S0) were estimated using the experimentally obtained density and speed of sound respectively along with the partial molar expansibility(Eϕ0), its first-order derivative ∂Eϕ0/∂TP and pair-triplet interaction coefficients (VAB,KAB,VABB; KABB). The apparent molar properties recommend the existence of strong (solute and solvent) interactions in the ternary mixture which is also justified by the positive partial molar expansibility values, while the partial molar properties suggest the formation of the hydrogen bond in the mixture. With Passynski's equation the hydration number (nh) for PG/HG in aqueous solutions of biotin is calculated utilizing the compressibility data and the obtained results are explained in terms of combined hydration effects and hydrophobic effect.

Elucidation of molecular interactions between amino acid and imidazolium based ionic liquid in an aqueous system: Volumetric and acoustic studies

Some of the most active academic and scientific research faces of the past decade are on ionic liquids and their behavior for industrial purposes. In the present work, the densities and sound velocities of an amino acid (glycine) in pharmaceutically active ionic liquid 1-Butyl-3-methylimidazolium hexafluorophosphate [BMIm][PF6] solutions were measured at different temperatures ranging from 293.15 K to 318.15 K under atmospheric pressure. The experimental data has been further used to calculate volumetric and acoustic parameters such as apparent molar volumes, VΦ and apparent molar isentropic compression, KΦ partial molar expansion, EΦ0 partial molar volume, VΦ0 and partial molar isentropic compression KΦ0 and corresponding empirical constants, Sv and Sk. The negative values are obtained for partial molar volume of transfer, ΔtVΦo at all temperatures and become more negative by increasing the concentration of the ionic liquid. The positive values of partial molar expansibilities, EΦo are decreasing with an increase in temperature predict increasing electrostriction. The obtained values of expansibilities show the structure-making/breaking ability of glycine in investigated solutions.

Understanding the interactions between protein stabilizers and the peptide bond through the analysis of the volumetric and compressibility properties for the model systems

This work confirms our earlier supposition, that volumetric and acoustic parameters for simple model proposed by us are directly related to stabilizing/destabilizing effect of osmolytes on proteins structure. The apparent molar volumes, VΦ, and the apparent molar isentropic compressions, KS, Φ, of glycine and N,N,N –trimethylglycine (betaine) were determined from densities and speed of sound measurements in aqueous solution of N-methylacetamide (as a model of peptide bond of protein). The standard molar parameters for osmolytes were obtained from concentration dependence of the calculated quantities at NMA concentration equal 2, 4, 6 and 8 (mol/kg) and at temperature T = (288.15, 298.15 and 308.15) K. The standard values were combined with volumetric and compressibility data for amino acids in pure water to obtain transfer properties from water to aqueous N-methylacetamide solutions. The standard partial molar volume of transfer of studied osmolytes, ΔtVΦ0, seems to be related mainly to hydrophilic/hydrophobic features of molecules. The stabilizing/destabilizing effect of solute on protein structure is reflected in temperature influence on the limiting partial molar quantities.

Volumetric and ultrasonic studies of molecular interactions of glycols in aqueous Niacin (vitamin B3) at different temperatures

At the temperature range of (293.15, 298.15, 303.15 and 308.15) K, the speed of sound and density values for ternary solution (Niacin+ water + Ethylene glycol (EG)/Diethylene glycol (DEG)/Triethylene glycol (TEG)) were measured at atmospheric pressure and (0.02, 0.04 and 0.06) mol·kg−1 niacin concentrations. The acoustic and volumetric properties of the mixture are analyzed though the calculated parameters i.e. Apparent Molar Volume (Vϕ), Partial Molar Volume (Vϕ0) and Partial Molar Volume of transfer (ΔVϕ0), which are determined from the experimental density values and Apparent Molar Isentropic compression (Kϕ, S), Partial Molar Isentropic compression (Kϕ, S0) and Partial Molar Isentropic compression of transfer (ΔKϕ0) are calculated using the speed of sound. The pair and triplet coefficients (VAB, VABB, KAB, KABB) are calculated, using which the significant details regarding the ternary mixture from these thermodynamical parameters are reviewed in terms of (solute-solvent) and (solute-solute) interactions.

Effect of α–amino acids (glycine, l-alanine, l-valine and l-leucine) on volumetric and acoustic properties of aqueous 1-Butyl-3-propylimidazolium bromide at T = (288.15, 298.15, 308.15, 318.15) K

In this experimental work, values of density and speed of sound of some α–amino acids viz.; glycine, l-alanine, l-valine and l-leucine with different molal concentrations of IL; 1-Butyl-3-propylimidazolium bromide ([BPim][Br]) at four working temperatures and experimental pressure p = 0.1 MPa have been determined. Using the corresponding data, different thermo physical parameters like apparent molar volume Vϕ, partial molar volume (Vϕ0), standard partial molar volume of transfer (ΔVϕ0), apparent molar isentropic compression (Kϕ,s), partial molar isentropic compression (Kϕ,s0) and partial molar isentropic compression of transfer (ΔKϕ,s0) have been calculated. Interaction coefficients have been determined using McMillan–Mayer theory and IR spectral studies have also been performed to validate the results obtained. The structural behaviour of all the α–amino acids (α-AAs) under consideration in ([BPim][Br]) and various types of interactions occurring in the ternary systems have been predicted from the results of various parameters.

Physicochemical studies on vitamins B1, B3, B6 and C in aqueous magnesium chloride solutions at different temperatures (288.15–318.15) K and at pressure (101.3) kPa

Vitamins are the precursors of many coenzymes essential for biocatalysts and their deficiency leads to diseases in masses. The vitamins are very fragile and can easily be destroyed with change external atmosphere. Electrolytes are inherent constituents of cytoplasm and are required in variety of biochemical functions. The interactions occurring between, solute-cosolute and solvent can be inferenced and interpreted from thermodynamic and transport studies effectively which will help in interpreting the mechanism of vitamins in solution phase. In the present study apparent molar volume ϕV, and viscosity B-coefficient B, have been determined for l-ascorbic acid (Vit.C), nicotinic acid (Vit.B3), thiamine hydrochloride (HCl salt of Vit. B1) and pyridoxine hydrochloride (HCl salt of Vit. B6) in aqueous magnesium chloride solutions (mB = 0.1 to 0.5 mol∙kg−1) over the temperature range (288.15–318.15) K at pressure (101.3) kPa. The partial molar volume of transfer, ∆trϕVo, and viscosity B-coefficient of transfer, ∆trB, for these compounds from water to aqueous solutions of magnesium chloride have been determined from the corresponding data. First (∂ϕVo/ ∂T) P and second (∂2ϕVo/ ∂T2)P, derivative of ϕVo and dB/dT, values have been calculated. B/ϕVo ratio, activation free energy of viscous flow of vitamins ∆μ2o#, and other parameters have also been calculated. Both volumetric and viscometric studies suggest the presence of complex interactions at lower concentrations, but the role of cosolute becomes decisive at higher concentrations. The dB/dT values and activation parameters (∆S2o#, ∆H2o#) values suggest that l-ascorbic acid, thiamine hydrochloride and pyridoxine hydrochloride show bond making tendencies with magnesium chloride while nicotinic acid shows comparatively less affinity with magnesium chloride.

Molecular interaction studies of antidepressant drug with aqueous caffeine using volumetric and acoustic methods

Knowledge of drug interactions and the factors controlling these interactions could be useful to overcome their adverse effects on human health. In this study, the effect of caffeine on the antidepressant action of escitalopram oxalate was investigated to explore the behavior of escitalopram oxalate in the presence of caffeine in terms of molecular interactions in an aqueous system at temperature range 293.15 to 313.15 K and atmospheric pressure. Density (ρ) and ultrasonic velocity (u) of escitalopram oxalate in different concentrations of caffeine solutions were measured at the selected range of temperatures. Experimental data has been used to calculate apparent molar volume (Φv) and apparent molar isentropic compressibility (Φv) and fitted to the Redlich–Mayer equation to obtain limiting parameters. Negative deviations from Debye–Huckel limiting law of apparent molar volume for the drug in the presence of caffeine were observed which can be used as a direct measure of the ion-ion and ion–solvent interactions. Partial molar volumes of transfer (ΔtΦvο) were found to be negative for the studied mixture. The partial molar expansibilities and Hepler's constant (∂2∅V0/∂T2) were found to be positive for the mixture (escitalopram oxalate+ caffeine) in water. Intermolecular free length (Lf) and compressibility hydration number (nH) were also analyzed. Obtained results were explored in terms of molecular interactions prevailing among escitalopram oxalate and caffeine molecules in aqueous solutions.

Interactional Behavior and Hydration Characteristics of Polyhydroxysolutes (d(+)-Xylose and d(−)-Ribose) in Aqueous Solutions of Dipotassium Oxalate at Different Temperatures

Thermodynamic properties revealing the hydration characteristics and structural effects of saccharides in mixed aqueous solutions generate considerable information for the growth of pharmaceutical and food industries. In this study, the apparent molar volumes, Vϕ, and the apparent molar isentropic compression, Kϕ,s, for monosaccharides (d(+)-xylose and d(−)-ribose) within the concentration range 0.1–1.0 mol·kg–1 in 0.0, 0.2, 0.4, and 0.6 mol·kg–1 aqueous solutions of dipotassium oxalate (K2C2O4) have been calculated from densities and speeds of sound measured at temperatures T = 288.15, 298.15, 308.15, and 318.15 K and experimental pressure p = 0.1 MPa. Thermodynamic parameters, partial molar volumes, Vϕo, partial molar volumes of transfer, ΔVϕo, partial molar isentropic compression, Kϕ,so, and partial molar isentropic compression of transfer, ΔKϕ,so, and hydration numbers, Nw, are also derived for the said monosaccharides. The effect of temperature on these parameters is studied, and further the expansion coefficients, (∂Vϕ0/∂T)p, (∂2Vϕ0/∂2T)p, and pair (VAB, KAB) and triplet (VABB, KABB) interaction coefficients are determined for monosaccharides. The results indicate the occurrence of strong solute–cosolute (hydrophilic–ionic and hydrophilic–hydrophilic type) interactions in these systems, which increase with the increasing concentration of saccharides and dipotassium oxalate.

Volumetric and Viscometric Properties of Maltitol in Glycylglycine Aqueous Solutions at T = 293.15–333.15 K

The densities and viscosities of maltitol in glycylglycine aqueous solutions were measured at T = 293.15, 303.15, 313.15, 323.15, and 333.15 K and at atmospheric pressure. Furthermore, the apparent molar volume (Vφ), the limiting partial molar volume (Vφ0), the limiting partial molar volume of transfer (ΔtrVφ0), the viscosity B coefficient, and the active free energies per mole of the solvent and solute (Δμ10≠ and Δμ20≠) were obtained from the experimental densities and viscosities. Moreover, the limiting partial molar volume of transfer was analyzed based on the cosphere overlap model, and the active free energies were also discussed according to the transition-state theory. The results indicate that the ion–hydrophilic interaction between the maltitol and glycylglycine molecules occupies a dominant position in the solution, and maltitol tends to act as a structural maker in the glycylglycine aqueous solution.

Molecular interactions studies of doxycycline hyclate in water, aqueous L-phenylalanine and glycyl glycine at different temperatures by using volumetric, ultrasonic and viscometric parameters

The density, sound velocity and viscosity of doxycycline hyclate in water, aqueous solution of L-phenylalanine and aqueous solution of glycyl glycine have been determined at different temperatures (305.15, 310.15, 315.15 and 320.15) K. The calculated values of partial molar volume (V_ϕ^o), standard partial molar volume of transfer (〖Δ_tr V〗_ϕ^o), partial molar adiabatic compressibility (κ_(ϕ,s)^o) and partial molar adiabatic compressibility of transfer (〖Δ_tr κ〗_(ϕ,s)^o) for doxycycline hyclate in water, aqueous solution of L-phenylalanine and aqueous solution of glycyl glycine infer the dominance of ion-hydrophilic interactions over hydrophobic-hydrophobic interactions. The Jones-Dole viscosity B-coefficient, viscosity B-coefficient of transfer (ΔtrB), free energy of activation of viscous flow per mole of pure solvent (〖Δμ〗_1^(o*)) and solute (〖Δμ〗_2^(o*) ), respectively, activation entropy (〖ΔS〗_2^(o*)) and activation enthalpy (〖ΔH〗_2^(o*)) of doxycycline hyclate in water, aqueous solution of L-phenylalanine and aqueous solution of glycyl glycine also have been calculated using viscosity data. The structure making and breaking behaviour of doxycycline hyclate in water, aqueous solution of L-phenylalanine and aqueous solution of glycyl glycine are obtained from the values of Hepler’s constant i.e.((δ^2 V_ϕ^o)/(δT^2 )) and (dB/dT). The presence and absence of caging effect has been studied with the help of partial molar adiabatic expansibility (E_ϕ^o). The isobaric thermal expansion coefficient (α^o= (E_ϕ^o)/(V_ϕ^o )), intermolecular free length and acoustic impedance for doxycycline hyclate in water, aqueous solution of L-phenylalanine and aqueous solution of glycyl glycine also have been determined.

Temperature-dependent physicochemical studies of some glycols in aqueous d-mannitol solution

The interlinkage of ethylene glycol, diethylene glycol and triethylene glycol with d-mannitol at different values of temperature has been analysed by the combination of volumetric and acoustic process. Different values of speed of sound and the density of EG, DEG and TEG in the molalities of (0.01, 0.03 and 0.05) mol kg−1 in aqueous solutions of d-mannitol at T = (293.15, 298.15, 303.15 and 308.15) K have been considered. From the values of speed of sound, the partial molar isentropic compression (Kϕ,s) and the partial molar isentropic compression of transfer $$(\Delta {\rm K}_{{\phi ,{\text{s}}}}^{0}$$ ), have been determined. The pair and triplet interaction coefficient have also been estimated. From the density data, the apparent molar volume $$(V_{\phi }^{0}$$ ) and standard partial molar volume of transfer $$(\Delta V_{\phi }^{0} )$$ for EG, DEG and TEG in aqueous d-mannitol solutions have been examined. Using the values of partial molar volume and partial molar isentropic compression of transfer, the pair and triplet coefficients are determined. These noteworthy parameters are helpful to examine the interactions between sugar alcohol + glycols + water solutions.

Exploration of the solvation behavior of the synthesized 1-hexyl-3-methylimidazolium bromide [C6mim][Br] ionic liquid with L-cysteine and N-acetyl L-cysteine) in aqueous medium at different temperatures

The interactions of L-cysteine and N-acetyl L-cysteine with imidazolium-based ionic liquid 1-hexyl-3-methylimidazolium bromide [C6mim] [Br] as a function of temperature have been studied by a combination of volumetric and acoustic properties. Densities and speeds of the sound of L-cysteine and N-acetyl L-cysteine in (0.00, 0.005, 0.01, 0.03 and 0.05) mol.kg−1 aqueous solutions of 1-hexyl-3-methylimidazolium bromide have been measured at T = (288.15, 298.15, 308.15 and 318.15) K. From density data, the apparent molar volume (Vϕ) the partial molar volume (Vϕ0) and standard partial molar volumes of transfer (ΔVϕ0) for L-cysteine and N-acetyl L-cysteine from water to aqueous 1-hexyl-3-methylimidazolium bromide solutions have been calculated. Partial molar isentropic compression (Kϕ,s) and partial molar isentropic compression of transfer (ΔKϕ, S0) have been calculated from the speed of sound data. The pair and triplet interaction coefficient have been calculated from both these properties. The parameters obtained have been used to describe the results in terms of (solute-solute), (solute-solvent) interactions, structure building and structure floating behavior of amino acids in aqueous 1-hexyl-3-methylimidazolium bromide solutions.

Solvation properties of glycine and glycylglycine in aqueous 1-hexyl-3-methylimidazolium bromide solution at different temperatures

Densities ρ, Speed of sound u and FTIR spectral studies for ternary mixture including ionic liquid 1-hexyl-3-methylimidazolium bromide, water and amino acids were measured over the entire composition range and at five temperatures from 288.15 K to 308.15 K and atmospheric pressure by means of vibrating tube densitometer DSA 5000. Different parameters have been calculated by utilizing the experimental data of density and speed of sound. The transfer parameter such as the partial molar volume of transfer (ΔVϕ0) and partial molar isentropic compression of transfer (ΔKϕ,S0) have been determined by using the limiting apparent molar volume (Vϕ0) and limiting apparent molar isentropic compression (Kϕ,s0) data respectively. The result has been used to discuss the nature and strength of intermolecular interactions in these mixtures. Apparent molar and partial molar parameters concerning volumetric calculate that the solute-solvent interactions are dominating in the ternary system. The pair and triplet interaction coefficients found from partial molar volumes of transfer and partial molar isentropic compression of transfer explain the dominance of pairwise interactions. FT-IR spectra have been noted down for the mixture of amino acids and ionic liquid (1-hexyl-3-methylimidazolium bromide). The aim of this work is to study the solute-solvent interactions prevailing in the ternary mixture.

Insight into intermolecular interactions and hydration properties of biologically active amino acids in aqueous solutions of cefepime: volumetric, compressibility and viscometric studies

The measurement of density, speed of sound and viscosity of an amino acid and its dipeptide i.e., glycine and glycylglycine in aqueous solution of antibiotic drug cefepime has been carried out at various temperatures. The density and speed of sound data has been used to obtain partial molar volume partial molar expansion coefficient second derivative hydration number (), isentropic compressibility partial molar isentropic compressibility partial molar volume of transfer and partial molar isentropic compressibility of transfer The viscosity data have been used to calculate the viscosity B–coefficients, its temperature derivative dB/dT, viscosity B–coefficient of transfer () and various thermodynamic parameters of activation of viscous flow i.e., and for amino acid/peptide in cefepime solutions. The dependence of these parameters upon concentration and temperature clearly suggests the role of amino acid/peptide and cefepime in solute-solvent interactions. The obtained results have been explained on the basis of competing pattern of interactions between the co-solute and solute in the studied ternary system in order to deduce important information regarding drug-amino acid/peptide interactions.

Volumetric and ultrasonic studies of molecular interactions of glycols in aqueous glutaraldehyde solutions at different temperatures

In the current work, Density and speed of sound (ultrasonic speed) of liquid mixtures of (ethylene, diethylene and triethylene glycols + aqueous glutaraldehyde solutions) have been investigated at the temperature ranges of (293.15 K, 298.15 K, 303.15 K and 308.15 K) and in the concentration of (0.01, 0.02, 0.03 and 0.04) mol·kg−1. Different thermodynamic and acoustic parameters have also been calculated using density and speed of sound experimental values. Vϕ (apparent molar) and Vϕ0 (partial molar) volumes and ΔVϕ0 (partial molar volume of transfer) have been estimated using experimental values of density. Using speed of sound values, Kϕ, s (apparent molar) and Kϕ, s0 (partial molar) isentropic compressions and ΔKϕ, s0 (partial molar isentropic compression of transfer) have been obtained. Using partial molar volume of transfer and partial molar isentropic compression of transfer values, the pair and triplet interaction coefficients have also been computed. The final outcome of the research is studied in terms of solute-solvent interactions between the molecules of liquid mixtures.

Effect of presence of tetra alkyl ammonium bromides on solution behavior of 1-Butyl-2, 3-dimethylimidazolium chloride at different temperatures: Volumetric and acoustic studies

Abstract Densities (ρ) and ultrasonic velocities (u) of 1-Butyl-2,3-dimethylimidazolium chloride, [bdmim]Cl, in aqueous solutions of tetra-n‑butyl ammonium bromide (TBAB) and tetra-n-propyl ammonium bromide (TPAB) have been measured at T = (298.15 to313.15)K. The apparent molar volume, Vϕand the apparent molar isentropic compressibility, Kϕ, s of the IL have been calculated. Both limiting apparent molar volume, V ϕ 0 and limiting apparent molar isentropic compressibility, K ϕ , S 0 were calculated using Redlich-Rosenfeld-Meyer (RRM) type equation and these values are compared with Masson type equation. The positive value of limiting apparent molar expansivity, E ϕ 0 indicates the ionic liquid (IL) has structure making effect. The increase in standard partial molar volume of transfer, Δ V ϕ 0 and standard partial molar isentropic compression of transfer, Δ K ϕ , S 0 of [bdmim]Cl with increasing TBAB concentrations has been explained by Friedman-Krishann co-sphere model. Moreover, some acoustic parameters were estimated using the experimental data at T= (298.15–313.15) K for justifying several interactions in the ternery solutions.

Drug-drug and drug-solvent interaction studies of Chloroquine phosphate, Acefylline piperazine and Gentamicin sulfate in polymeric systems

The densities of three pharmacologically significantly used drugs i.e., Chloroquine phosphate (CP), Acefylline piperazine (AP) and Gentamicin sulfate (GS) have been carried out in aqueous (aq), aqueous polyethylene glycol (aq-PEG) and aqueous polyvinyl pyrrolidone (aq-PVP) solvent systems within concentration range (0.02–0.1 ± 0.001 mol.dm−3) at different temperatures (293.15–318.15 K) with the interval of 5 K. Density data were used to evaluate volumetric properties of drugs (CP, AP and GS) by apparent molar volume, partial molar volumes, molar expansibilities and isothermal expansion coefficient. ϕE° provides information about the absence or presence of a caging or packing effect. Partial molar transfer volume was also calculated to study the hydrophilic/hydrophobic interactions in aq-PEG and aq-PVP solvent systems. The results are interpreted in terms of drug–solvent and drug-drug interactions and structure making or breaking abilities of drugs in aq, aq-PEG and aq-PVP solvent systems.