Experimental and model study on the multiple chemical equilibrium for reactive extraction of ibuprofen enantiomers with HP-β-CD as hydrophilic selector

Hydrophilic β-cyclodextrin derivatives (β-CD) were used for the enantioselective extraction of hydrophobic ibuprofen (IBU) enantiomers from organic solvent to aqueous phase in a batch system at 10 °C. Process variables including types of organic solvents and β-cyclodextrin derivatives, concentration of selector, pH and temperature, strongly influence the efficiency of extraction. The experimental data were described by a reactive extraction model with a homogeneous aqueous phase reaction of R,S-IBU with HP-β-CD. The model predictions were compared graphically with the results of experiments and the model was further used to predict the extraction efficiency influenced simultaneously by the two process variables of pH and HP-β-CD concentration. The good agreement between the modeled and experimental data was obtained. By modeling and experiment, an optimal extraction condition with pH of 2.5 and HP-β-CD concentration of 0.03 mol/L was obtained with enantioselectivity (α) of 1.24 and performance factor (pf) of 0.029. The model was verified experimentally with excellent results.