Poly(propylene glycol) vs Sugar Alcohol-Based Aqueous Biphasic System to Extract Drugs and Subsequent Recovery of the Polymer

Abstract

A carbohydrate-based aqueous biphasic system (ABS) has been designed by adding an aqueous solution of sugar alcohols (D-mannitol and glycerol) to poly(propylene glycol) (PPG#400). The phase diagrams of the ABSs have been constructed using the turbidometric titration method at 309 K. The tie-line lengths and the slope of tie lines of the system have been obtained using the gravimetric method. The use of sugar alcohol to replace the salt-rich phase for phase separation makes the ABS apt for extracting different molecules of biological relevance. Using one of these newly constructed eco-friendly ABSs, D-mannitol vs PPG#400, the extraction behaviors of Ivermectin and Doxycycline (which have been extensively used to treat COVID-19 patients) were studied at different pH values. About 90% of Ivermectin and 70% of Doxycycline has been extracted to the polymer-rich phase of ABS at pH 7 in single extraction. The extraction patterns of these two drugs remain almost the same even in the presence of Lascorbic acid and zinc acetate, which are also administered as combination drugs in the treatment of COVID-19. We have also studied the extraction behavior of Prednisolone, a corticosteroid, which also is widely recommended to particularly treat the severity of the cytokine storm that arises in many patients at the third phase of COVID-19. Complete extraction of Prednisolone has been achieved at pHs 3 and 5, and ∼97% of extraction has been achieved at pH 7. The objective of such extraction is to design cleaner methods of remediation of these drugs to minimize their exposure to the environment that may lead to drug resistance in the environment. We have also recovered the polymer using thermoseparation and adsorption techniques after extraction experiments to make the method environmentally as well as economically viable.

Green Extraction Strategy Using Bio-Based Aqueous Biphasic Systems for Polyphenol Valorization from Grape By-Product

“…Although the isolation step is outside of the scope of the experimental study reported here, some suggestions are provided with respect to how to isolate and reuse the ABS components (dashed lines in Figure 10 ) to further emphasize the sustainable character of the process. RSV could be easily recovered from the PPG-rich phase by antisolvent crystallization, whereby adding water as antisolvent can significantly lower the solubility of hydrophobic polyphenol [ 61 ]. Isolation from the IL matrix could be achieved using affinity resins.…”

Amino Acid and Block Copolymer-Based ABS: An Efficient Extraction Tool for PPIs and Consequent Recovery of the Polymer

“…Thermoseparation, deprotinization, ultrafiltration, adsorption, etc. are some of the recognized techniques to recover the polymer-rich phase of the ABS. ,, In the present work, block copolymers, which are highly thermosensitive in nature, have been used to form the polymer-rich phase of the ABS. Thus, after the extraction experiment, first, the thermoseparation technique has been used to recover the polymer.…”