“…As in the previous section, IL-based ABS and/or aqueous solutions of ILs have been investigated in the separation and purification of pharmaceuticals. IL-based ABS design should consider water-stable [ 4 , 8 , 12 , 168 ] and, whenever possible, more benign ILs [ 22 , 38 , 169 , 170 ], combined with various phase-forming agents, such as salts [ 28 , 120 , 126 , 171 , 172 ], polymers [ 39 , 172 , 173 , 174 , 175 ], surfactants [ 176 ], amino acids [ 177 ] and polar organic solvents [ 178 , 179 ]. Among these, Shahriari et al [ 40 ] reported, for the first time, the existence of ABS composed of cholinium-based ILs and the inorganic salt K 3 PO 4 , followed by their application to separate tetracycline and its hydrochloride salt.…”