Binodal Curves and Tie-Line Compositions for a Poly(ethylene glycol) 6000 + Lithium Citrate + Water Aqueous Two-Phase System and the Partitioning of Salbutamol Drug at T = 288.15–318.15 K

The partitioning of salbutamol drug in a poly­(ethylene glycol) 6000 + lithium citrate + water system was investigated at T = 288.15, 298.15, 308.15, and 318.15 K. The binodal curves and tie-line compositions were determined at different temperatures, and the studied aqueous two-phase system (ATPS) was used to study the partitioning of salbutamol drug. The results showed that the ability of the system for two-phase formation increases at higher temperatures. The good performance of the empirical Merchuk equation was obtained to model the binodal curves. The tie-line compositions were also fitted using the Setschenow-type equation and electrolyte Wilson models. Furthermore, the ability of the studied ATPSs for the extraction of salbutamol is shown based on the obtained partitioning parameters, and the partitioning coefficient was increased from the value of ∼0.48 at T = 288.15 K to ∼1.7 at T = 318.15 K. Overall, the studied ATPS can be employed to extract salbutamol from aqueous medium in a range of biological temperatures.