Understanding the Thermodynamic Behavior of Diclofenac Adsorbed on Graphene Sheets: The Role of Water Molecules and Temperature
نویسندگان
1 Department of Pharmaceutics, College of Pharmacy, University of Al-Ameed, Kerbala, Iraq
2 Department of Chemistry, College of Sciences for Women, University of Babylon, Hilla, Iraq
3 Department of Chemistry, College of Sciences for Women, University of Babylon, Hilla, Iraq
4 Department of Pharmacy, Al-Manara College for Medical Sciences, (Maysan), Iraq
5 Al-Hadi University College, Baghdad, 10011, Iraq
6 Department of Medical Laboratories Technology, AL-Nisour University College, Baghdad, Iraq
7 Mazaya University College, Thi-qar, Iraq
doi
10.48309/ajca.2025.534818.1883چکیده
Characterization of the interaction of drug molecules with solvent media is essential in the context of drug delivery, formulation, and performance. The adsorption behavior and energy profiles of the Diclofenac drug molecule with different amounts of water molecules (0, 10, 20, 50, 75, or 100) at the Adsorption Locator module level (COMPASS force field) was studied through molecular simulations, using a fixed temperature of 298 K. Besides, as to the temperature effect (288 K, 298 K, 303 K, and 328 K), the propensity of the energy landscape in the system with 100 water molecules was also examined to comprehend the thermodynamics trend. Our results reveal that the total adsorption energy and isosteric heat (Qst) of Diclofenac significantly increase with the number of H2O molecules, suggesting stronger interaction and clustering effects. At greater water contents, energy distributions broadened, reflecting increased configuration diversity and potentially cooperative phenomena between water and drug. Additionally, temperature dependence resulted in an increased trend of energy destabilization at higher temperatures, manifested by distinctive changes in the positions of energy distribution peaks and reduction of interaction specificity, indicating the sensitivity of adsorption behavior to temperature. Molecular visualizations of the conformations supported the energetic analyses, with denser hydrogen bonding networks and drug encapsulation, being more pronounced at higher water concentrations. The extensive data provide key insights into solvent effects upon the behavior of drugs and are useful for the drug design and solvation modeling.
