Partition of parthenolide in ternary {block copolymer + biocompatible ionic liquid or natural deep eutectic solvent + water} systems

In this work, aqueous biphasic systems (ABSs) formed by copolymers, ionic liquids (ILs) and natural deep eutectic solvents (NADES) have been demonstrated to be effective separation platforms for the extraction of hydrophobic pharmaceutical ingredients such as parthenolide (PAR). This work addresses the determination of the liquid–liquid equilibrium of ABS composed of choline lactate IL or choline chloride – lactic acid NADES and two different block copolymers Pluronic (PL17R4 and PL10R5), and their influence on the ABS formation and extraction efficiency of PAR. The ability of Pluronics to form ABS is compared to widely used polypropylene glycol polymer (PPG400). Comparing the effect of the ionic liquid and NADES on the ABS formation, it is shown that both salting-our reagents successfully form ABS and do not affect the extraction efficiency of PAR. The main influence on the high parthenolide extraction efficiency (>96%) is governed by the hydrophobic interactions between Pluronic and investigated compound, regardless on the applied salting-out reagent. Due to a high extraction efficiency achieved in PL-rich phase and promissing medical features of PAR, obtained results showed that this phase could be used as biocompatible drug delivery system. Avoiding commercially available organic solvents, elevated temperatures and pressure, the proposed method is greener alternative for PAR extraction.