Study of Molecular Interactions of the H-1 Antihistamine Drug Chlorpheniramine (CP) in Water and in Aqueous Solutions of Urea, Glucose, and Sodium Chloride at Different Temperatures

The intermolecular interactions and solution properties of the antihistamine drug chlorpheniramine (CP) in aqueous, aqueous solutions of electrolyte and non-electrolyte have been examined in the current work using volumetric and spectroscopic approaches to investigate how the drug is affected by co-solutes. Also, a drug’s behavior in water and other aqueous systems can be studied to learn more about the chemistry of biological systems. Using an Anton Paar density and sound velocity meter, densities and sound velocities for CP (0–0.10 mol⋅kg⁻¹) at various temperatures (298.15, 308.15, and 318.15 K) in water and in aqueous 0.05 mol⋅kg⁻¹ urea, glucose, and sodium chloride have been measured to determine apparent molar properties: apparent molar volume (\(V_{\phi} )\) and apparent molar compressibility \((K_{\phi, {\mathrm{S}}})\). A number of derived parameters, including limiting apparent molar volume \(\left( {V_{\phi }^{0} } \right)\), limiting apparent molar compressibility (\(K_{\phi, {\mathrm{S}}}^{0})\), limiting apparent molar expansibility (\(\phi_{\mathrm{E}}^{0} )\), and isobaric thermal expansion coefficient (ɑ) were obtained using the data on apparent molar properties. While analyzing the data, solute–solvent interactions are taken into account, as well as their considerable effects on CP hydration when co-solutes, are introduced to the combination. The negative transfer properties suggest the predominance of ion-hydrophobic and hydrophobic-hydrophobic interactions in all the studied systems. Positive and small negative values of Hepler’s constant revealed the structure-making capability of CP in aqueous urea, glucose, and sodium chloride. Also, an IR study has been done to verify the results obtained from volumetric and compressibility data. Understanding how drugs behave in various solvent systems during drug development is made easier by understanding drug interactions.