Solubility Modeling of a Bupivacaine Hydrochloride in Various Solvents over a Wide Temperature Range

In the present work, the solubility parameters of the local anesthetic drug bupivacaine hydrochloride (BH) were measured. The pure solvents under study were methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, dimethylformamide (DMF), acetic acid, and water. Two binary solvent systems, namely, methanol + water and ethanol + water, were also used to determine the solubility. The experimental solubility of the BH was obtained by the gravimetric method over a series of temperatures (293.15–333.15 K) in different mono and binary solvents under atmospheric pressure. Experimental results reveal the dependence of solubility on temperature. The experimental mole fraction solubility was further correlated with theoretical models such as the Apelblat, λh, Van’t Hoff, modified Jouyban–Acree, and CNIBS/R–K models. The small values of RAD and RMSD indicated that the data are in good agreement with experimental data. The data of solubility can be applied in the fields of production, purification, crystallization, and separation of BH