Determination and correlation of solubility with thermodynamic analysis of lidocaine hydrochloride in pure and binary solvents

The objective of this work was to measure and correlate the solubility of lidocaine hydrochloride in eight pure solvents, including ethanol, n-propanol, isopropanol, n-butanol, isobutanol, acetone, methyl acetate, water, and binary mixtures at (291.15 to 331.15) K by using gravimetric method under atmospheric pressure. The results reveal that the solubility of lidocaine hydrochloride increases with increasing temperature in all solvent selected. The modified Apelblat equation, van't Hoff equation, λh equation, Wilson model and NRTL model were successfully used to correlate the experimental solubility in pure solvents and binary solvent mixtures. In addition, the thermodynamic properties of dissolution of Lidocaine hydrochloride such as Gibbs energy (∆G°sol), molar enthalpy of dissolution (∆H°sol), and molar entropy of dissolution (∆S°sol ) were calculated. Consequently, the experimental solubility and correlation equations can be used as essential data and simulation models in the purification and separation of lidocaine hydrochloride.