Effects of Solvent Polarity on Solvation Free Energy, Dipole Moment, Polarizability, Hyperpolarizability and Molecular Reactivity of Aspirin

Khan, Mohammad Firoz; Rashid, Ridwan Bin; Faruk, Md. Al; Rahman, Md. Mustafezur; Rashid, Mohammad A.

doi:10.22159/ijpps.2017v9i2.15853

Cited by 18 publications

(14 citation statements)

References 27 publications

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“…It has been reported that differences in solvent polarity and the type of solute-solvent interaction(s) have an impact on the physicochemical properties of molecules, attributing to interactions with the transition state of individual molecules. Therefore, differences in the stability and reactivity as well as the molecular spectrum of the molecule is expected (23)(24)(25)(26).…”

Section: Methods Validation For Determination Of Asamentioning

confidence: 99%

Impact of Solvent Selection and Absorptivity on Dissolution Testing of Acetylsalicylic Acid Enteric-Coated Tablets

Ata¹,

Tarawneh²,

Sejare³

et al. 2021

Dissolution Technol.

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The objective of this study was to investigate the effect of physiological conditions on the dissolution rate of acetylsalicylic acid (ASA) from two commercial brands compared against compendial tests. All parameters of the analysis were chosen according to ICH (Q2(R1)) guidelines and were validated statistically. The maximum wavelength (λ max ) and absorptivity (ε) for ASA were determined in different solvents at different pH values (6.8 and 4.9) by a validated UV-Vis spectrophotometric method. When ethanol (EtOH) was used as co-solvent, ε was found to be 3.15, and when 0.1 N NaOH was used, ε was 18.50. Dissolution tests were conducted according to pharmacopeia specifications; however, the lack of a direct specification in determining ε in the pharmacopeia has permitted enormous probabilities of employing different solvents. Herein, when NaOH was used to dissolve ASA, ε was calculated to be 18.50, and upon conducting compendial dissolution tests for enteric-coated tablets, only 20% of ASA was released after 4 h. When analyzing the same data using ε of 3.15 (calculated from dissolving ASA in EtOH), the amount of released ASA was found to be 95% after 2 h. Furthermore, the effect of a fed and fasted state pH was not significant on the dissolution rate, and both brands met the compendial requirements.

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Section: Methods Validation For Determination Of Asamentioning

confidence: 99%

Impact of Solvent Selection and Absorptivity on Dissolution Testing of Acetylsalicylic Acid Enteric-Coated Tablets

Ata¹,

Tarawneh²,

Sejare³

et al. 2021

Dissolution Technol.

View full text Add to dashboard Cite

show abstract

“…The global chemical reactivity descriptors in (Table 1and Table 2) such as ionization potential (I), electron affinity (A), lowest unoccupied molecular orbital (ELUMO), highest occupied molecular orbital (EHOMO), and energy gap (Eg). electronegativity (χ), chemical potential (μ), molecular hardness (η), molecular softness (s), electrophilicity index (ω), Nucleofugality (ΔΕ ), and Electroofugality (ΔΕ ) in different types of solvents using equations (1-8) as shown below [27][28][29][30] . Where, I is ionization potential (I = -EHOMO) and A is electron affinity (A = -ELUMO).…”

Section: Global Reactivity Descriptors and Dipole Momentmentioning

confidence: 99%

Theoretical Study for Chemical Reactivity Descriptors of Tetrathiafulvalene in gas phase and solvent phases based on Density Functional Theory

Shahab

Husain

2021

PJBAS

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The aim of the study is to investigate the effects of solvent polarity on the frontier molecular orbitals energy gap and global chemical reactivity of Tetrathiafulvalene in order to understand the stability and reactivity of Tetrathiafulvalene in a different solvent medium. Density functional theory with (B3LYP/6-311++G) basis set was used to perform a variety of calculations in both the gas and solvent phases. Besides dipole moment, Mulliken charge distribution, and thermodynamic properties were calculated in five solvent phases namely (water, acetone, Tetrahydrofuran (THF), Carbon tetrachloride (CCl4), and benzene). The calculations were carried out using the Gaussian 09 software, and the results showed that the solvents have an effect on the optimized parameters. Moreover, Mulliken population analysis, and local reactivity as Fukui Functions (FFs) from the natural bond orbitals (NBO) charges are computed to understand the electrophile, nucleophile region, and chemical activity of the title molecule. The dipole moment in gas phase and solvent medium is 0.00 Debye. Also, it was observed that the global chemical reactivity parameters change depending on the molecular structure and polarity of the solvents. Tetrathiafulvalene molecule was observed to have greater stability (low reactivity) in the water solvent with an EHOMO-ELUMO energy gap of 3.946 eV while it has higher reactivity (low stability) in the gas phase with EHOMO-ELUMO energy gap of 3.872eV. finally, this result indicates that Tetrathiafulvalene is an excellent candidate for future studies of semiconductor and optoelectronic materials.

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“…In the last decades, the solvent's significant effect on the dipole moment has been reported in the literature. [48][49][50][51] It is found that the dipole moment is bigger in solution than in the gas phase. The dipole moment increases when going from lower to higher dielectric constant, i.e.…”

Section: Solvent Effectsmentioning

confidence: 99%

Quantum Chemistry of Cocaine and its Isomers I: Energetics, Reactivity and Solvation

2021

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We investigate the rich stereochemistry of cocaine and its diastereoisomers from a theoretical perspective using density functional theory. The relative stability of the eight considered isomers is discussed, and a comparison of the corresponding internal coordinates is given. Our results reveal that the S-pseudococaine isomer is the most stable conformation, whereas the natural occurring isomer (R-cocaine) lies higher in energy. The different isomers' chemical reactivity is discussed based on the calculation of the hardness, softness, electrophilicity and dipole moment. It was found that the dipole moment varies over a broad range from 0.65 to 4.60 D, whereas the other properties are slightly modified. The solvent effect on the energy stability of the cocaine isomers was studied by considering chloroform, dimethyl-sulfoxide (DMSO) and water as implicit solvents. Our calculations show that the different isomers' energy order and their energy gaps are slightly modified due to solvent effects. However, in all cases, the S-pseudococaine remains the most stable isomer. However, the dipole moment and the chemical reactivity of the cocaine isomers increase with the solvent polarity. Keywords: Cocaine isomers,DFT, stability, solvent effect, chemical reactivity.

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Effects of Solvent Polarity on Solvation Free Energy, Dipole Moment, Polarizability, Hyperpolarizability and Molecular Reactivity of Aspirin

Cited by 18 publications

References 27 publications

Impact of Solvent Selection and Absorptivity on Dissolution Testing of Acetylsalicylic Acid Enteric-Coated Tablets

Impact of Solvent Selection and Absorptivity on Dissolution Testing of Acetylsalicylic Acid Enteric-Coated Tablets

Theoretical Study for Chemical Reactivity Descriptors of Tetrathiafulvalene in gas phase and solvent phases based on Density Functional Theory

Quantum Chemistry of Cocaine and its Isomers I: Energetics, Reactivity and Solvation

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