Elucidation of Interactions between Ciprofloxacin Hydrochloride Monohydrate and Constituents of Nucleic Acids in Aqueous Solutions at Different Temperatures

Abstract

The interaction of drugs with nucleic acids is one of the most essential parts of biological research in the drug discovery and pharmaceutical development processes. Furthermore, physicochemical studies of the solution behavior of such systems are extremely desirable for elucidating the various interactions in aqueous solutions. Therefore, in this context, measurements of the density (ρ), speed of sound (u), viscosity (η), and enthalpy of dilution (q) for uracil, thymine, uridine, and thymidine in water and in aqueous solutions of ciprofloxacin hydrochloride monohydrate (Cfx) at m B (molality of Cfx in water) = (5, 10, 15, 20, 25) mmol·kg–1 across the temperature range of T = (288.15 to 318.15) K and at p = 1 × 105 Pa have been performed. Furthermore, these data have been utilized to evaluate partial molar volumes, partial molar isentropic compressions, viscosity B coefficients, standard molar enthalpies of dilution, and their corresponding transfer parameters (Δtr V 2,Φ 0, Δtr K s,2,Φ 0, Δtr B, and ΔtrΔdil H°). These properties have been used to elucidate the presence of solute–solvent interactions. The solute–Cfx interactions are exothermic in nature, according to calorimetry studies. Furthermore, the UV–visible studies show that the interactions between the pyrimidine-based molecules and drug result in a shift in wavelength (λ) as well as a change in absorption.