(2024) 18:153
Tegegn and Wirtu ﻿BMC Chemistry
https://doi.org/10.1186/s13065-024-01262-8

BMC Chemistry

RESEARCH

Open Access

The impact of thermophysical properties
on eflornithine drug solute in acetone and ethyl
acetate solvent interactions at varying
concentrations and temperatures
Dereje Fedasa Tegegn1* and Shuma Fayera Wirtu1

Abstract
The study was conducted on the impact of thermophysical properties on eflornithine drug solute–solvent
interactions in aqueous ethyl acetate and acetone at different concentrations and temperatures. The aim of thisstudy is to enhance the understanding of eflornithine’s behavior in different solvents, which is crucial for its effective
use in pharmaceutical applications. The density, molar volume, viscometric, and conductometric characteristicsof the eflornithine drug solutions (0.025, 0.05, 0.075, 0.1, and 0.125 mol/kg) in acetone and 25% (v/v) aqueous
ethyl acetate were measured within a temperature range of 298.15 K–318.15 K. Based on the determined density
parameters, the following parameters were assessed: viscosity (η), equivalent molar conductance, limiting apparent
molar volume (­ V0φ), apparent molar volume of transfer ­( V0φtr), and apparent molar volume (Vφ). The Masson
empirical relationship and the viscosity-to-Jones-Dole (JD) equation were used to evaluate the partial molar volume(Vφ), experimental slope ­(SV), viscosity, and density data. Temperature and concentration were used to determine
each parameter. For each set of dilutions, conductometric studies were conducted in both study solvents. The
gathered data was analyzed in order to evaluate the ion–solvent interactions. The Walden product Λomηo’s positive
temperature coefficient values indicate that the drug eflornithine functions as a structural modifier in acetone
and aqueous acetyl acetate systems. The structure-making and breaking characteristics of the polar solvents acetone
and ethyl acetate were identified.
Keywords Molar volume, Density, Eflornithine drug, Thermal conductance, Viscosity
Introduction
Drugs have been used for a very long time as importantchemicals that help identify, reduce, and predict diseases
in living organisms. Due to its complex structure, it is hardto probe how drugs interact with large biomolecules such
*Correspondence:
Dereje Fedasa Tegegn
derejefedasakiya@gmail.com
1
Department of Chemistry, College of Natural and Computational
Science, Dambi Dollo University, P. O. Box. 260, Dambi Dollo, Oromia,
Ethiopia

as sugars, proteins, and carbohydrates [1]. However, thesolute–solvent interactions in mixed aqueous solutions
can be understood through thermodynamic and thermophysical properties. The presence of hydrophilic andhydrophobic groups in the drug molecules causes them tointeract with other molecules differently in the solution.
Density (ρ), volumetric, acoustic, and conductance data
are some parameters derived from which useful information concerning the structural features and properties ofsolutions can be obtained. Nevertheless, volumetric andacoustic characteristics offer insights into the kind of interaction existing between solute and solvent [2].

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Tegegn and Wirtu ﻿BMC Chemistry(2024) 18:153

Understanding biological processes is significant for
applications in the pharmaceutical research and laboratory industries. This can be achieved by studying the thermophysical properties of organic compounds in aqueous
mixed solvents [3]. Important properties in the characterization of solute–solvent interactions are density, conductance, and viscosity. Eflornithine is an oral ornithine
decarboxylase inhibitor that treats adults and children at
high-risk of neuroblastoma [31–33]. A solution’s thermophysical behavior is the culmination of all potential interactions between solute particles and the solvent, as wellas other systemic manifestations [4]. Important insights
into solute–solvent interactions can be gained from thethermophysical characteristics of the drug eflornithine inacetone and aqueous ethyl acetate solutions. The natureof the solute and solvent, as well as whether the solutealters or distorts the solvent’s structure, are well understood from solute–solvent interactions [5–7]. Inferences
about these interactions are derived from conductancemolar volume and viscosity studies in mixed solventsare particularly interesting because unusual results are
obtained in the majority of solvent systems [8].
The several articles provide a detailed understandingof the interaction between solute and solvent using
properties such as conductance, density, and viscosity [9–13]. The components of solvent mixtures hold ions that
constitute the eflornithine drug or its components, which
affect its solubility in acetone and ethyl acetate solutions.
Apart from the disintegration process of the solute
molecules, some particular consequences resulting fromvarious types of particle solvation are very important. For
grasping the general features of any solution, different
crystal solvents can be very problematic in both researchlaboratories and chemical industries. Solvent mixtures
have an essential role to play; they are useful where
they enhance chemical reactivity by enhancing reactant
dissolution or product separation, for example, mixed
solvents [14].
Different methods can be used to analyze the effects of
mixed solvent and temperature on solute–solvent interactions [15–17]. Ion–solvent interactions in acetone andcertain organic solvents have been investigated, but theireffects in solvent mixtures have received less attention[18]. When it comes to revealing the different kinds ofinteractions taking place in solutions, volumetric properties are crucial. These are also useful in explaining thenature of the solute in the solvent, intermolecular interactions, and the solvent’s ability to create or disrupt structures [19–24]. Determining density and then evaluating
apparent molar volume, limiting apparent molar volume,and calculating the intrinsic coefficient or experimental slope are the best ways to gain insight into volumetric properties. The viscous flow of organic compounds

Page 2 of 13

between adjacent liquid layers is measured by viscosity,
which is an important physical property of liquids [25].
From a pharmaceutical perspective, viscosity is associated with how well a drug enters the body and proceeds
through physiological and metabolic processes across biological membranes.
Conductivity is the material’s capacity to conduct
power and is connected with the ionic items in the solution. Conductivity estimations are the most modest anddependable approach to estimating ionic items in solutions to compute the boundary of thermophysical properties. The goal of this work is to determine how theeflornithine drug solute is impacted by solvent interactions among (­CH3)2CO and ethyl acetate derivation at
various concentrations and temperatures. The viscosity, conductance, and consistency of eflornithine in fluid
ethyl acetate and ­(CH3)2CO dissolvable at various temperatures in the range of 298.15 K and 318.15 K must
likewise be estimated by experimental evidence [26–28].
Molar composition going from 0.00 to 0.125 ­kg−1.mol,
volumetric, viscometric, and conductometric concentrations as a component of dissolvablity and temperature
were utilized in light of their importance. Particle-solvent
interactions were utilized to decide how these boundaries relied upon temperature and concentrations [29,30]. Generally, Understanding eflornithine’s behavior indifferent solvents is crucial for designing effective andstable drug formulations, optimizing solubility and stability, developing accurate models, and improving energyefficient manufacturing processes, ultimately enhancing
the overall effectiveness and efficiency of eflornithine as apharmaceutical product.

Materials and methods
Chemicals

Chemicals were employed along with molar mass, provenance, mass fraction purity, chemical abstract service
numbers, and purification method for the investigationof the effects of the drug eflornithine concentration indifferent concentrations of aqueous acetone and aqueous ethyl acetate solutions at different temperatures. The
all chemicals used in this study were greater than 99%.
Aqueous acetone and aqueous ethyl acetate (mass fraction purity > 0.99) were acquired from Dambi Dollo University’s Chemistry Laboratory, while eflornithine (massfraction purity > 0.99) was purchased from Sigma Aldrichand used as such. Aqueous ethyl acetate and acetone wereused to prepare each solution. Analytical reagent grade
was prepared using eflornithine drug, acetone, aqueous
ethyl acetate (­CH3COOC2H5), and acetone + 25% (v/v)
aqueous ethyl acetate. Throughout the work, flasks, measuring cylinders, beakers, specific gravity, and conductivity cells were cleaned using distilled water and potassium

Tegegn and Wirtu ﻿BMC Chemistry(2024) 18:153

permanganate. Moreover, KCl was utilized to standardize
the conductometric cell [5].
Instrumentation

The densities of the solutions were estimated utilizing asolitary, slim, explicit gravity made of borosilicate glasswith a bulb limit of approximately 50 ml. The particulargravity was fixed for around 30 min in a thermostatic
water bath to diminish warm uncertainties. In viscosity,
all through the trial measures, a conductance of
1.414 ­cm−1 was ready, and the marks were adjusted
utilizing refined water at different temperatures. An
electronic balance would be utilized to quantify the
mass. The eflornithine drug solutions were made utilizing
weight and molality, which were then changed overcompletely to molarities utilizing standard lapses. The
vibroviscometer, which initially aligns with refined water,would be utilized to measure viscosity. To lessen warm
variance, the vibro viscometer wouldn’t allow remaining
in a water bath with indoor regulator control. Standard
conductive cells were utilized to quantify conductivity. A
standard of 0.01 m potassium chloride (KCl) was madefor the conductivity cell. Prior to being utilized in theexperiment, the materials were cleaned and dried in adrying boiler at 100 °C for one hour. A thermometer was
likewise used to gauge the temperature; all measurements
except for viscosity were made in a water bath utilizing
an indoor air regulator that vacillated in temperature.
Methods
Preparation of solutions

Solutions were arranged utilizing triple-refined deionized water with a particular conductance of under 1­ 0–6
S.cm−1. A molality premise was utilized to set up thearrangements for the readiness of the eflornithine drugin ­(CH3)2CO and 25% v/v ethyl acetate ­(CH3COOC2H5).
98% v/v (0.00–0.125 ­kg−1.mol) accurate amounts ofeflornithine would be prepared in (­CH3)2CO and­(CH3COOC2H5) at different temperature ranges from2981.5 K–318.15 K. Furthermore, 0.01 m of potassium
chloride (KCl) was utilized as an alignment standard forthe conductivity cell, and utilizing refined water, it was an
adjustment of specific gravity.
Measurement of density

Specific gravity method Specific gravity was utilized tocompute densities with the utilization of dry air and water[9]. The particular gravity was estimated using a gravity
bottle and an overall estimation technique. The density (ρ)
was found with an exactness of 1 × ­10–4 g/cm3. The temperature was consequently kept at that level. For the predefined molality values, by dissolving the proper sum in acetone and ethyl acetate and mixing dissolvable separately

Page 3 of 13

at various temperatures ranges from 298.15 to 318.15 K.
Each weight of eflornithine drug in (­CH3)2CO and 25%
ethyl acetate (­CH3COOC2H5) was added to determine
gravity. The mass of the solutions was then estimated atevery conc. and temperature, at long last, specific gravity
was utilized. To ascertain the densities of solutions, all inall, the particular gravity volume is separated by the massof the arrangement in unambiguous gravity less the massof the unfilled specific gravity.
Measurement of conductanceStandard conductive cells were utilized to gauge conductivity. An adjustment standard of 0.01 m potassium
chloride (KCl) was made for the conductivity cell. Set up
the ­(CH3)2CO and 25% ethyl acetate (­CH3COOC2H5)
0.00–0.125 mol.kg−1 solution of the eflornithine drug
and measure the outcomes at different temperatures,going from 298.15 to 318.15 K, to peruse the conductivity at every temperature. An experiment was conductedwith ± 0.01 °C temperature accuracy. Every arrangement
was blended for 30 s utilizing an attractive stirrer andafterward permitted to represent one moment. Each conductivity estimation was performed threefold or until arecurrent value was acquired. For a conductivity cell witha known cell arrangement and for every temperature,
wash the cell each time with.
Determination of Walden’s rule

Walden’s standard was expressed as the result of thesame conductance or restricting molar conductance [15].
At boundless dilutions of an electrolyte in a given dissolvable, the viscosity of that dissolvable is a constant.
Furthermore, it utilizes structure-making and structurebreaking, as determined. First, set up the solutions of
the eflornithine drug in ­(CH3)2CO and 25% ethyl acetate­(CH3COOC2H5) 0.00–0.125 mol.kg−1 at various temperatures ranging from 298.15–318.15 K, ready to peruse theconductivity at every temperature. The restricting molar
conductance and viscosity of dissolvables at infinite dilutions of every solution utilizes conductivity cell and avibro viscometer inside a known cell constant.
Measurement of viscosity

One significant physical quantity is viscosity [18]. In thisstudy, a vibro viscometer was employed. In the current
study, viscosity was assessed at a temperature range of
298.15–318.15 K while thermostatic conditions were inplace. A mixture of acetone, 25% (v/v) aqueous ethyl acetate, and 98% (v/v) (0.00–0.125 mol.kg−1) of eflornithine
drug was produced by dissolving the appropriate amountin distilled water at varying temperatures, ranging from298.15 to 318.15 K. Viscosity values at each temperature
were measured after each solution was stirred for 30 s

Tegegn and Wirtu ﻿BMC Chemistry(2024) 18:153

Page 4 of 13

using a magnetic stirrer and then allowed to stand forone minute. Every viscosity measurement was performed
three times or until a repeat value was obtained. Then foreach solution and each temperature was measured.

Results and discussion
Volumetric studies
Density measurement

Density measurements were made to acquire comprehension of volumetric qualities, which are helpful in recognizing the kinds of intermolecular interactions [13].
The density data for all dilutions of the eflornithine drugin ­(CH3)2CO and 25% ethyl aceticate ­(CH3COOC2H5)
is depicted below (Table 1). In a watery solution of(CH3)2CO and 25% ethyl acetate ­(CH3COOC2H5), theexploratory upsides of arrangement density for the eflornithine drug (0.00–0.125 mol.kg−1) were estimated at different temperatures T = (298.15, 303.15, 308.15, 313.15,
318.15) K. Table 3 records the density upsides of themultitude of arrangements at different temperatures. It
is seen that, for arrangements containing explicit groupings of ­(CH3)2CO and ethyl acetate, the viscosity of thesolutions increases as the concentration of the eflornithine rises and marginally diminishes as the temperature
increases. In view of the volume extension acquired bydecreasing the intermolecular forces between the particles of the dissolvable and the eflornithine, the value of
thickness diminished as temperature rose.
Experimental values of density for aqueous solutions­(CH3)2CO and ethyl acetate at various temperatures are

in great agreement with literature value [29]. The experimental densities for the combination show a similar
pattern, as revealed in the table below (Table 2). Temperature-subordinate varieties in density values occur ina successive way, implying that density values decline astemperatures rise in solutions of liquid ­(CH3)2CO andethyl acetate as solvents. The experimental upsides ofdensities (ρ) the obvious molar volume the restricting
clear molar volume, and the evident molar exchange ofthe eflornithine drug are recorded in (Tables 1, 2, 3, 4 and5) separately listed below.
The densities of aqueous solutions of solutes have been
computed using the following equation:

ρ=

W − WsVs(1)where, W is the weight of solution, Vs is the volume ofthe specific gravity bottle, Ws is the weight of specificgravity bottle.
Apparent molar volume

Apparent molar volume is a useful concept forunderstanding solute–solvent interactions in a solution.
It represents the change in volume when a solute is added
to a solvent, accounting for the interactions between thesolute and solvent molecules [25]. The apparent molar
volumes (Vφ) of Eflornithine drug solutions in acetone
and aqueous ethyl acetate (v/v) have been calculated
from the density values of the solvent and solution byusing the relation.

Table 1 Origin and quality of the examined chemical samples:
Chemical Name

Molar mass
(g.mol−1)

Provenance

Mass fraction Structure
PurityChemical
Abstract Service
numberEflornithine (2,5-diamino-2(difluoromethyl) pentanoic acid
hydrate)236.65Sigma Aldrich> 0.9970,052-12-9Acetone46

DaDU Chem lab> 0.9967-64-1Ethyl acetate

88

DaDU Chem lab> 0.99141-78-6

Tegegn and Wirtu ﻿BMC Chemistry(2024) 18:153

Page 5 of 13

Table 2 Densities of solutions of Eflornithine drug in acetone and 25% (v/v) aqueous C­ H3COOC2H5 at different temperatures andconcentrations of solvents as functions of the molality (m) of Eflornithine drug and temperature
Concentration (m ­(kg−1.mol)) Temperature (K)298.15−3

303.15308.15313.15318.15–3

Eflornithine drug + acetone ρ(kg.m ) × ­10
0.000

0.98710.98570.9841

0.98220.98020.025

0.98870.98690.98540.9841

0.98230.050

1.0001

0.9981

0.99690.9956

0.99410.075

1.00110.9994

0.9981

0.99670.99540.100

1.00191.00030.9991

0.99790.99670.125

1.00281.00151.00010.9991

0.9982Eflornithine drug + 25% (v/v) aqueous ethyl acetate ρ(kg.m−3) × ­10–3
0.000

0.90710.90470.90150.89790.89550.025

0.89890.89590.89290.88920.88710.050

0.90010.89730.89480.89130.8891

0.075

0.90210.89910.89620.89310.89110.100

0.90410.90120.89830.89530.89310.125

0.90630.90410.90110.89810.8958303.15308.15313.15318.15

3Standard uncertainty of T = ± 0.01 K, ρ = 0.01 kg/m

Table 3 Apparent molar volume (Vφ)
Concentration (m(kg−1.mol)) T(K)298.15
3–4Eflornithine drug + acetone Vφ ­(cm .mol ) × ­10
−1

0.000

83.62884.59

85.52986.0789

86.8450.025

83.14184.02484.86885.42186.1590.050

82.75483.52184.39184.89185.5930.075

82.41483.161

83.93184.46185.0940.100

82.19882.84983.55184.02984.6710.125

82.01682.59883.191

83.66184.246

Eflornithine drug + 25% (v/v) aqueous ethyl acetate Vφ ­(cm3.mol−1) × ­10–4
0.000

93.05893.68694.11494.43294.9560.025

92.42592.98193.42193.80894.3030.050

91.88592.34192.78193.26193.6890.075

91.27491.72692.19192.64193.0650.100

90.65191.17891.67192.10792.5090.125

90.05190.59191.18791.55191.871

Standard uncertainty of T =  ± 0.01 K, V = 0.02LVϕ =(ρo − ρ)
M2
+
ρ
mρρo

(2)

where, Vφ represents the molar volume of the electrolyte, ρ is the density of the solution, ρ0 is the densityof the solvent, m is the molality of the solution, andM2 is the molecular weight of the eflornithine drug.
The density (ρ) molar volume of the arrangements ofdifferent concentrations for various frameworks was
accompanying. The clear molar volume information of
the multitude of preparations of eflornithine drug inboth solvents of study at all working temperatures isobtained from the below determined data (Table 3). It
is acquired that the value free from molar volume lessened with an increase in concentration and increased
with an the increase in temperature. The diminishedTegegn and Wirtu ﻿BMC Chemistry(2024) 18:153

Page 6 of 13

Table 4 Limiting molar volume (V0φ) and experimental slope, (Sv)
Eflornithine drug in acetone
V0φ (10−4 × cm3.mol −1)

3

Sv (

−1

cm .mol√−1
mol.Kg)Concentration (m­(kg−1.mol)

298.15303.15308.15313.15318.15

0.000

82.48

83.49

84.53

85.54

86.25

0.00

0.00

0.00

0.00

0.00

0.025

81.95

82.99

84.03

84.99

85.71

− 21.2− 20.00− 20.00− 22.0− 21.60

0.050

81.61

82.56

83.65

84.55

85.25

− 13.6− 17.20− 15.20− 17.6− 18.4

0.075

81.41

82.26

83.29

84.06

84.86

− 8.00− 12.00− 14.40− 19.6− 15.6

0.100

81.14

81.98

82.96

83.69

84.48

− 10.8− 11.20− 13.20− 14.8− 15.20

0.125

80.93

81.71

82.62

83.41

84.11

− 8.40− 10.80− 13.60− 11.2− 14.80298.15303.15308.15313.15318.15Eflornithine drug in 25% (v/v) aqueous ethyl acetate
0.000

92.86

93.39

93.99

94.43

94.96

0.00

0.00

0.00

0.00

0.00

0.025

92.33

92.85

93.38

93.88

94.35

− 21.20− 21.60− 24.40− 22.00− 24.40

0.050

91.82

92.31

92.77

93.26

93.77

− 20.40− 21.60− 41.20− 24.80− 23.20

0.075

91.31

91.79

92.19

92.66

93.15

− 20.40− 20.80− 23.20− 24.00− 24.80

0.100

90.84

91.26

91.66

92.12

92.49

− 18.80− 21.20− 21.20− 21.60− 26.40

0.125

90.42

90.75

91.09

91.55

91.91

− 16.80− 20.40− 22.80− 22.80− 23.20

Standard uncertainty of T =  ± 0.01 K, V = 0.02L

Table 5 the transfer volume, ­V0φtr values for Eflornithine drug
from acetone to aqueous ethyl acetate solutions
V0φtr ­(10–4 ­cm3. mol −1)
Eflornithine drug from acetone to aqueous ethyl acetate (v/v)
solutionsConcentration(m ­(kg−1.mol))

298.15303.15308.15313.15318.15

0.000

10.38

9.91

9.46

8.89

8.71

0.025

10.36

9.86

9.35

8.89

8.64

0.050

10.21

9.75

9.12

8.71

8.52

0.075

9.91

9.53

8.91

8.61

8.29

0.100

9.28

9.28

8.71

8.43

8.01

0.125

9.49

8.71

8.47

8.14

7.81

3

Standard uncertainty of T =  ± 0.01 K, V = 0.02L, ρ = 0.01 kg/m

value with concentration is related to the compression
in volume due to the change in mean distance and solvophobic hydration between the eflornithine drug polargroups and solvent. The weaker intermolecular interactions cause a decrease in apparent molar volume, which
increases with temperature. Furthermore, the ethylgroup in ethyl acetate causes steric hindrance in theway of electrostriction, which causes a change in volume. This is related to the gradually increasing apparent
molar volume in ethyl acetate as compared to acetone.
Conversely, ethyl acetates apparent molar volumes insolution are greater than those of acetones.

The apparent molar volume values in double mixtures
decline as the eflornithine concentration rises as the
proportion of ethyl acetate in combinations increases.
The apparent molar volume values increased too suggesting a strengthening of the solute–solute interactions in mixtures. The addition of the solute brings
about a bigger change in the apparent molar volume inlight of the solvents feeble way to deal with the soluteparticles. These volumes are moved in ­(CH3)2CO ethyl
acetate rather than acetone. This shows the strong andvariable associates between solutes and solvent. The
clear molar volume likewise followed a similar example
increasing with temperature across all frameworks anddemonstrating the presence of a weak particle dissolvable collaboration at higher concentrations as needs be
the value V of the eflornithine drug in the ­(CH3)2COand ethyl acetate are positive solutions implying thatthe medication goes about as a design creator in thefluid ­(CH3)2CO and ethyl acetate. The molar volume
esteems graphically (Fig. 1). The apparent molar volume of eflornithine drug solutions in (­CH3)2CO andethyl acetate fluid at different temperatures and concentrations is displayed in Fig. 1. Plots of eflornithine
drug solutions in fluid (­CH3)2CO (Fig. 1A) and eflornithine drug solutions in ethyl acetate (Fig. 1B) at
298.15 K–318.15 K were drawn. It was found that theclear molar volumes differed directly with the molality
thus the information was fitted to the straight condition
utilizing the least-squares method.

Tegegn and Wirtu ﻿BMC Chemistry(2024) 18:153

Page 7 of 13A

88

298.15Vφ(cm3.mol-1)10-4

87

303.1586308.1585313.15318.15

84
83

82
81
0

0.025

0.05

0.075

0.1

0.125

0.15

m1/2(kg-1.mol)
Eflornithine drug + Acetone

B96298.15VΦ(cm3.mol-1)10-4

95

303.1594308.1593313.1592318.15

91

90
89
0

0.025

0.05

0.075

0.1

0.125

0.15

m1/2(kg-1.mol)
Eflornithine + Ethyl acetate
Fig. 1 Experimental values of apparent molar volume
versus concentrations of Eflornithine drug in acetone (A)and aqueous ethyl acetate (B) at different temperatureand concentrations

Limiting apparent molar volume

The values of limiting partial molar volume, ­V0φ andthe slope, S­ v, have been obtained using method of linear
regression of V
­ φ versus molality of Eflornithine drug inacetone and aqueous ethyl acetate (v/v) solvents from thefollowing relation [25].
√Vϕ = V0 ϕ + Sv m
(3)
where, ­V0φ is the limiting apparent molar volume (equal
to infinite dilution partial molar volume). It gives themeasure of ion–solvent interactions present in solution.
The ­Sv is an experimental slope and given a measure ofion-ion interactions present in the solution. The negative
Sv values show that the strong electrostatic ion–solvent
interactions which cause ionic association and weaken
ion-ion interactions. From the data already available
in the literature for different solvents including water,
can be concluded that, in general, (i) the value of slope

more smaller is favored if the dielectric constant of themedium is high whether the solvent is hydrogen bonded
or non-hydrogen bonded [37, 38] and (ii) the electrostatic
ion-ion interaction is weak due to the large ionic sizeor due to the very high dielectric constant. Strong
electrostatic solvation (primary solvation) is responsible
for the decrease of ­[dV0φ/dT] values. Similarly, weakelectrostatic solvation is responsible for the increase of­[dV0φ/dT] values [39–41].
If the calculated values of ­V0φ and ­SV for Eflornithine
drug solutions in acetone and aqueous ethyl acetate
are summarized in Table 4. The value of limiting molar
volume is found to be positive and increased in linear
manner with temperature indicating strong solute–
solvent interactions. This must be explained by theorganic compound’s solvation and hydration behavior,
the decrease in electrostriction, and the volume changebrought on by the solvent migrating from the second
layer surrounding the drug Eflornithine to the bulk
solvent. The experimental slope value was found to be
negative, suggesting poor solute–solute interactions andthe drug Eflornithine’s hydrophobic nature, which results
in insufficient counter-ion binding with solute moleculesand decreases with concentration. The drug Eflornithine’s
dissociation pattern in solution is thought to havedecreased as indicated by the decreased or negative valueof ­SV with temperature.
The positive value of V
­ 0φ indicates strong solute–solvent interactions. The volume behavior of a solute at infinite dilution is satisfactorily represented by ­V0φ which is
independent of solute–solute interactions and provides
information concerning solute–solvent interactions. As
demonstrated in Table 4 the V­ 0φ are large positive forall the mixtures at all the investigated temperatures, suggesting the presence of strong solute–solvent interactions
and weak solute–solute interactions in these systems.
The increase in ­V0φ values with increase in temperaturefor Eflornithine drug solutions in acetone and aqueous
ethyl acetate can be explained by considering the size ofprimary and secondary solvation layers (Fig. 2). At higher
temperatures, the solvent from the secondary solvation
layer of Eflornithine drug is released into the bulk of thesolvent, resulting in the expansion of the solution, as
inferred from large V­ 0φ values at higher temperatures.
0
The values of ­V φ increase with increase in concentrationof ethyl acetate indicating that solute–solvent interactions are increasing with the concentration of co-solute.
In the present systems, the V­ 0φ values increase withincreasing temperature suggesting the increase of solute–solvent interactions with temperature. An increasein temperature reduces the electrostriction and hence­V0φ increases. The values of experimental slopes ­(SV)
which are indicative of solute–solute interactions are

Tegegn and Wirtu ﻿BMC Chemistry(2024) 18:153

Page 8 of 13A

87

298.15V0Φ(cm3.mol-1)

86303.1585308.1584313.1583318.15

82
81
80
0

0.025

0.05

0.075

0.1

0.125

0.15

m1/2(kg-1/2.mol1/2)

Transfer volume

In Acetone

V0Φ(cm3.mol-1

B
95.5
95
94.5
94
93.5
93
92.5
92
91.5
91
90.5
90

298.15303.15308.15313.15318.15

0

0.025

0.05

0.075

0.1

utilizing the apparent molar volume and limiting apparent molar volumes of electrolyte solutions [34–36]. The
limiting apparent molar volume of electrolytes at infinite
dilution are useful to study ion–solvent and solvent–solvent interactions, while its dependence on the concentration can be used to study ion-ion interaction. So, thevalues of V0φ eflornithine drug in acetone and 25% (v/v)
aqueous ethyl acetate solutions are positive indicates that
Eflornithine drug in acetone behaves as structure making
in acetone and 25% (v/v) aqueous ethyl acetate.

0.125

0.15

m1/2(kg-1/2.mol1/2)
In ethyl acetate
Fig. 2 Experimental values of limiting molar volume
versus concentrations of Eflornithine drug in acetone (A)and aqueous ethyl acetate (B) at different temperatureand concentrations

found to be positive as well as negative but smaller than­V0φ values, suggesting that solute–solute interactions are
weaker than solute–solvent interactions in the systems
under study. The below Table 4 depicted that the limiting
molar volume and the values of experimental slopes (­ SV)of studied systems. The S­ V values are always smaller thanthe ­V0φ values for all the studied solutions and this factindicates that the ion–solvent interactions play a dominant role over the ion-ion interactions in characterizing
the volumetric properties.
In the study of solute–solvent interactions in aqueous
solutions, limiting the apparent molar volumes of solutes
at infinite dilution offers a useful tool. Limiting apparent molar volume data in aqueous solutions are available
for a variety of electrolytes and non-electrolytes. Molar
volumes of electrolytes have been studied extensively inboth aqueous and non-aqueous solvents [26–30]. Theinteractions (i.e., ion-ion, ion–solvent, and solvent–solvent) that occur in solutions can be better understood by

The transfer volume is a concept used to describe thechange in volume when a solute is transferred from one
solvent to another. This parameter is particularly usefulin understanding solute–solvent interactions and thesolvation process [42, 43]. Limiting apparent molar
properties of transfer volume V­ 0φtr provide qualitative as
well as quantitative information regarding solute–solvent
interactions without taking into account the effects ofsolute–solute interactions. The transfer volumes, V­ 0φtr ofEflornithine drug from acetone and aqueous ethyl acetate
solutions were calculated by using the relation.

V0 ϕtr = V0 ϕaqueous ethyl acetate − V0 ϕacetone(4)

where ­V0φacetone is the limiting apparent molar volumeof Eflornithine drug in a­ cetoneV0φ aqueous ethyl acetate is thelimiting apparent molar volume of Eflornithine drug inaqueous ethyl acetate.
The ­V0φtr values for Eflornithine drug from acetone toaqueous ethyl acetate solutions are depicted (Table 5).
Data in Table 5 indicates that ­V0φ of Eflornithine drug are
more than those in acetone, i.e. ­V0φtr values are positive.
The ­V0φtr are all positive and increase with an increasein the concentration of aqueous ethyl acetate for each
Eflornithine drug, which implies a larger dehydration
effect on Eflornithine drug. Observed positive valuesof ­V0φtr suggest strong ion–solvent interactions ofaqueous ethyl acetate with Eflornithine drug. Because
the structural moiety of the drug eflornithine andaqueous ethyl acetate both contain polar groups thatcause interactions, the solute’s ability to form structuresin the solution is enhanced. Additionally, the solutes’
solvophobic solvation and the structural interaction
between two co-spheres, as predicted by the co-sphere
overlap model, are responsible for the observed positivetransfer volume values, which also point to the solutes’
structure-promoting/maker nature. Because of the small
contribution from solute–solute interactions in thecontext of the co-sphere overlap model with respect to­V0φtr, they offer insights into solute–solvent interactions.
The possibility of various interactions that occur between

Tegegn and Wirtu ﻿BMC Chemistry(2024) 18:153

Page 9 of 13

Eflornithine drug and aquose ethyl acetate molecules
could be.
(i) ion-hydrophilic interactions (between zwitterionic
centers of Eflornithine drug and polar groups ofaqueous ethyl acetate)(ii) hydrophilic-hydrophilic interactions (between
polar groups of Eflornithine drug and polar groupsof aqueous ethyl acetate)(iii) ion-hydrophobic
interactions(between
zwitterionic centers of Eflornithine drug and nonpolar groups of ethyl acetate) and(iv) Hydrophobic-hydrophobic interactions (between
non-polar groups of Eflornithine drug and nonpolar groups of ethyl acetate).
According to co-sphere overlap model, ion-hydrophobic interactions and hydrophobic-hydrophobic interactions contribute negatively whereas ion-hydrophilic andhydrophilic-hydrophilic interactions contribute positively to the V­ 0φtr values. This would lead to positive volume transfer or in other words it could say that there isan increase in electrostriction.
At higher percentages of ethyl acetate, hydrophilicinteractions predominate over hydrophobic interactions in the ethyl acetate-acetone system of the drug
eflornithine. The behavior of both positive and negativetransfer volumes is comparable to the first study. so, thepositive value ­V0φtr Eflornithine drug in acetone and
25% (v/v) aqueous ethyl acetate solutions indicates that

Eflornithine drug behaves structure in case of making
25% (v/v) aqueous ethyl acetate.
Conductance measurement

Electrical conductivity is a reliable indicator of theintermolecular interactions and plays a significant rolein defining the nature of solutions [44]. The following
Table 6 and Fig. 3 show that the value of electricalconductivity in the current study increased withconcentration as well as temperature. This is explainedby the fact that temperature and concentration bothincrease the number of charge carriers and their mobility.
There is a correlation between the two factors and higher
electrical conductivity values. Additionally, the increased
conductivity values do not increase as temperature andconcentration rise, most likely because of intermolecularinteractions that provide steric hindrance to charge
carrier mobility. The two solvents under investigation
both followed this pattern. In acetone and aqueous
ethyl acetate systems, the conductivities were utilized tocompute the molar conductance for the drug eflornithineat various temperatures and electrolyte concentrations.
When an electrolyte solution is diluted, its molar
conductance rises and eventually approaches a limiting
value. This value is called molar conductance at infinite
dilution (Λom). Molar conductance at infinite dilution has
been determined by the relation, as shown in Eq. 5 by thehuckle-Onsager’s (HO) equation as:

Table 6 The experimental values of equivalent conductance solutions of Eflornithine drug in acetone and aqueous 25% (v/v) ethyl
acetate at different temperatures and concentrations
Eflornithine drug + acetone: Equivalent conductivity (λm(Sm2mol−1))
T(K)Concentration(m(kg−1.mol))

298.15303.15308.15313.15318.150.000

127.03128.99130.59131.65132.500.025

126.25128.13129.75130.84131.650.050

125.59127.39129.01130.14131.01

0.075

124.88126.77128.19129.29130.090.100

123.99125.89127.22

128.22

129.130.125

122.99124.92

126.19127.09127.99Eflornithine drug + 25% (v/v) ethyl acetate: Equivalent conductivity (λm(Sm2mol−1))
0.000

105.98117.25127.25132.99140.12

0.025

103.23116.15125.98132.12138.91

0.050

102.12113.25124.15130.91137.650.075

100.12110.98120.25127.45133.980.100

95.680105.86115.91122.67129.560.125

90.820101.23110.25116.65123.45

Standard uncertainty of T =  ± 0.01 K, V = 0.02L, ρ = 0.01 kg/m3, Λ = 0.01 ­Sm2mol−1Tegegn and Wirtu ﻿BMC Chemistry(2024) 18:153

Page 10 of 13

A

134

λm(S.m2.mol-1)

132
130298.15128303.15126308.15124

313.15318.15

122
0

0.025

0.05

0.075

0.1

0.125

0.15

m1/2(kg-1/2.mol1/2)
Eflornithine + acetone
B

Determination of Walden’s rule140.324λm(S.m2.mol-1)

interactions have been diminished the restricting molar
conductance’s for eflornithine drug in (­CH3)2CO andethyl acetate solutions were acquired by extrapolating the direct plots of molar conductance versus to zero√conc. The plot of molar conductance versus m for eflornithine drug in ­(CH3)2CO and ethyl acetate is displayedin (Fig. 3). The restricting molar conductance for eflornithine drug in arrangements at 298.15, 303.15, 308.15,
313.15 and 318.15 K temperatures are kept in. Table 6
shows that restricting molar conductance incrementswith expansion in temperature which might be becauseof expansion in ionic versatility of particles at boundless
dilution.

298.15120.324303.15100.324308.15313.1580.324318.1560.32440.324
0

0.025

0.05

0.075

0.1

0.125

0.15

m1/2(kg-1/2.mol1/2)
Eflornithine + ethyl acetate

Fig. 3 Experimental values of equivalent molar conductanceversus concentrations of Eflornithine drug in acetone (A)and aqueous 25% (v/v) ethyl acetate (B) at different temperature
and at different concentrations√
�m = �om − (A + B�0m ) m(5)

where, Λom is the molar conductance at infinite dilution,
A and B are the constant for an electrolyte of a given
valence type in each particular solution. At the point
when the concentration of electrolytes in (­CH3)2COand ethyl acetate solvents increased the molar conductance diminished also. This exhibits that when soluteconc. increments more particles are created which dials
back particle development and brings down molar conductance. When solute conc. is weakened, particles
become free and show high qualities. the way of behaving of electrolytes in mixture dissolvable framework is
impacted by the natural solvents ­(CH3)2CO and ethyl
acetate which are pretty much aprotic and in this manner different properties like dielectric constant fascination powers and ionic connections can be concentrated
by physiochemical properties of electrolytes in blended
dissolvable frameworks molar conductance at boundlessweakening expanded with the expansion in temperature
while diminished with the increment of watery 25% (v/v)
ethyl acetate derivation. Subsequently, solute-dissolvable

The outcome showed that the restricting molar conductance (λ0) increment as the temperature increment yet
decline as the convergences of the Eflornithine drug inthe dissolvable combinations increments [45]. This pattern in restricting molar conductance can be all arounddepicted by the consistency conduct of the dissolvable
media. Overall consistency improvement was found toprevail over restricting molar conductance decrement
and thus Walden item (Λm × ɳ0) increment as the groupings of the Eflornithine drug in the dissolvable blends
increase. Nonetheless, the rising pattern of Walden item(Λm × ɳ0) with expanding temperature can be credited to
the warm extension of the dissolvable sheath because of
the initiations of the dissolvable atoms. Changes in Walden item with fixations are normal and they can ascribe
to changes in particle dissolvable connections. The Walden item information (Λm × ɳ0) has been records in Fig. 4.
The designs making/breaking nature of solute still up in
the air from temperatures coefficient of Walden item forexample [d(λm × ɳ0)/dT]. The positive temperatures coefficient of Walden item for Eflornithine drug in (­ CH3)2COand 25% ethyl acetate solutions shows that Eflornithine
drug acts as design making in ­(CH3)2CO and ethyl acetate. Figure 4 show that the plot of Λm × ɳ0 versus T for
Eflornithine drug in ­(CH3)2CO and ethyl acetate.
Viscosity measurement

Viscosity coefficients are crucial in understanding solute–solvent interactions. They provide insights into
how solutes affect the viscosity of a solution, which inturn reflects the nature of interactions between solute and solvent molecules [46]. The solute-dissolvable particle dissolvable cooperation’s can likewise be
examined as far as the progressions in property likeviscosity and conductivity from the beneath arranged
Table 7. Information it is obvious that worth of consistency got expanded with the conc. of solutions. Becauseof the advancement of solute and solute-dissolvableTegegn and Wirtu ﻿BMC Chemistry(2024) 18:153

Page 11 of 13

A

B

Fig. 4 Walden Product versus concentrations for Eflornithine drug at different concentrations in Acetone (A) and 25% (v/v) aqueous ethyl acetate(B) solutions at different temperatures

Table 7 The experimental values of viscosity and relative viscosity solutions of Eflornithine drug in acetone and aqueous 25% (v/v)
ethyl acetate at different temperatures and at different concentrations√η−1
η0 − 1/ m(specific—viscosity) Concentration(m(kg .mol)) Eflornithine drug + acetone
298.15303.15308.15313.15318.15298.15303.15308.15313.15318.150.000

0.8902

0.797

0.698

0.6826

0.676

0.00

0.00

0.00

0.00

0.00

0.025

0.90

0.891

0.87

0.86

0.85

0.696

0.743

1.5584

2.009

3.971

0.050

0.95

0.92

0.90

0.89

0.88

0.33

0.688

1.294

1.359

1.349

0.075

0.97

0.95

0.93

0.923

0.914

0.327

0.669

1.214

1.286

1.334

0.100

0.99

0.96

0.94

0.93

0.923

0.324

0.645

1.096

1.146

1.155

0.125

1.02

0.98

0.96

0.95

0.94

0.312

0.638

1.061

1.108

1.104

Eflornithine drug + 25% (v/v) aqueous ethyl acetate
0.000

0.44

0.39

0.37

0.35

0.33

0.00

0.00

0.00

0.00

0.00

0.025

0.77

0.75

0.74

0.72

0.70

4.743

5.838

6.324

6.686

7.091

0.050

0.82

0.78

0.77

0.76

0.74

3.862

4.472

4.834

5.239

5.556

0.075

0.85

0.82

0.79

0.77

0.75

3.402

4.025

4.644

4.782

4.947

0.100

0.97

0.95

0.912

0.874

0.85

3.351

3.84

4.372

4.442

4.682

0.125

1.05

0.97

0.95

0.93

0.90

3.218

3.206

4.152

4.244

4.462

Standard uncertainty of T =  ± 0.01 K, V = 0.02L, viscosity = 0.04%

interactions the obstruction in the progression of particles of solution creates. The viscosity of the eflornithine
drug solutions in ­(CH3)2CO and ethyl acetate diminished because of the breakdown of dissolvable andnatural particles associated through hydrogen bonds
because of the fulfillment of exorbitant dynamic energy
prompting diminished strength of intermolecularstrength. From Table 7 the density of eflornithine drug
solutions under concentration decline especially as
temperature is raised. As the temperature expanded
more atoms can escape from the potential wells givenby their neighbors thus the arrangement turns out
to be more liquid. The noticed worth of consistency
expanded with expanding eflornithine drug focus
because of the increment of the intermolecular powers
which cause to oppose in stream process.

Effects of density on solute–solvent interactions

The effects of density on solute–solvent interaction are
directly proportional to density. i.e., as the solute–solvent
interactions increase, the densities also increase, but
the temperature is vice versa. When the temperature
increased, the density of the solution was decrease as
seen in the above equations for density relationships.
Partial molar volume is one such property, and thesevolumes of electrolytes in mixed solvents have provenuseful in ascertaining the solute–solvent interaction.
Effects of conductance on solute–solvent interactions

Temperature increases cause an equal increase in an
arrangement’s conductance, which suggests that either
the particles of the arrangement free move at that

Tegegn and Wirtu ﻿BMC Chemistry(2024) 18:153

Page 12 of 13

condition and conductivity increases or the solute dissolvable collaboration of intermolecular power declines.

Acknowledgements
Not applicable.

Effects of viscosity on solute–solvent interactions

Author contributions
Dereje Fedasa contributed to the information collection, concept and layout
and drafted the manuscript, and Shuma Fayera contributed to the revision of
the manuscript for essential highbrow.

The impacts of solute-dissolvable collaborations on thearrangement viscosity can be derived from the B-coefficient. The viscosity temperature steadiness was exploredby contrasting it’s first at various temperatures. The viscosity decline implies a solute dissolvable association.
It declines when temperature increases in solutions,so the arrangement moves free and the viscosity of thearrangement diminishes the cooperation among solventand solute particles, causing an inhomogeneous viscosity conveyance of dissolvable particles around a solute.
The inhomogeneous viscosity dispersion brought about
by the dissolvable solute interaction acts the motions ofa solution.

Conclusion
The aim of this study is to enhance the understanding ofeflornithine’s behavior in different solvents, which is crucial for its effective use in pharmaceutical applications.
The information of densities, conductometry, and viscosity variations as well as the capability of concentrations
and temperature were studied in this study. Because of
the values of the obvious molar volume restricting evident
molar volume thickness and Walden, different boundaries demonstrate the presence of solid solute-dissolvableinteractions and weak solute cooperation with expanding eflornithine drug concentrations in ­(CH3)2CO while
showing the shortfall of solid solute-dissolvable interactions and the presence of solid solute associations. For theeflornithine drug in nearly ­(CH3)2CO and ethyl acetate
solute-dissolvable collaborations diminish the expansion
in the level of ethyl acetate in its fluid solutions and prevail at higher temperatures for water, though the soluteconnection escalates at higher temperatures for the nearly­(CH3)2CO and ethyl acetate mixture. These realities could
be ascribed to the transcendence of particle hydrophilic
and hydrophilic gathering transportations over particle
hydrophobic hydrophobic and hydrophilic-hydrophobic
connections. It is seen that eflornithine drug goes about asa design producer in these watery ethyl acetate solvents,
thus the ­V0φ, Walden products are positive. However, thedB/dt the value was negative in arrangements involving
the eflornithine drug in ethyl acetate and acetone, demonstrating that the eflornithine drug acts as design makingin ­(CH3)2CO and ethyl acetate.
Abbreviations
DaDU	Dambi Dollo University
HO	Huckle-Onsager’s
JD	Jones-Dole
SV	Molar volume slopes

Funding
This research received no external funding.
Availability of data and materials
The data sets used and analyzed during the current study are available fromthe corresponding author on reasonable request. We have presented all datain the form of Tables and Figures in the manuscript.

Declarations
Ethics approval and consent to participate
Not applicable.
Consent for publication
Not applicable.
Competing interests
The authors declare no competing interests.
Received: 2 March 2024 Accepted: 5 August 2024

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