Apparent molar volume and isentropic compressibilities of antidepressant drugs (Citalopram HBr and Escitalopram oxalate) with water

In this work, density and speed of sound were measured as a function of concentration for the two binary mixtures of Citalopram HBr and Escitalopram oxalate drugs in water at T = 293.15 to 318.15 K. From the experimental density and speed of sound data, the apparent molar volume (V) and apparent molar isentropic compressibility (κs,) were calculated and fitted to the Redlich-Mayer equation to obtain limiting parameters. The temperature dependence of apparent molar volume at infinite dilution (V) was fitted to the second order polynomial equation, to calculate the apparent molar expansibility at infinite dilution (E). The limiting apparent molar expansibilities at each temperature were found to be positive for binary mixtures of both drugs in water. Apparent molar and limiting apparent molar properties were analyzed to understand the drug-solvent interactions in studied systems. Moreover, structural ability of drugs is analyzed at experimental conditions.