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Equilibrium studies on enantioselective extraction of oxybutynin enantiomers by hydrophilic β‐cyclodextrin derivatives
Author(s) -
Tang Kewen,
Zhang Panliang,
Pan Chunyue,
Li Hongjian
Publication year - 2011
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.12513
Subject(s) - oxybutynin , chemistry , cyclodextrin , enantioselective synthesis , enantiomer , extraction (chemistry) , homogeneous , ionic strength , aqueous two phase system , ionic liquid , chromatography , aqueous solution , organic chemistry , thermodynamics , catalysis , medicine , alternative medicine , pathology , overactive bladder , physics
The enantioselective extraction of hydrophobic oxybutynin (OBN) enantiomers by hydrophilic β‐cyclodextrin (β‐CD) derivatives was studied. The efficiency of extraction depends strongly on a number of process variables such as types of organic solvents and β‐CD derivatives, concentration of selector, pH, and temperature. The experimental data were described by a reactive extraction model with a homogeneous aqueous phase reaction of R,S‐OBN with β‐CD. Important parameters of this model were determined experimentally. The physical distribution coefficients for molecular and ionic OBN were 4.96 × 10 −3 and 9.52, respectively. The equilibrium constants of the complexation reactions were 1770 and 1340 L/mol for S‐ and R‐OBN, respectively. By modeling and experiment, an optimal extraction condition with pH of 5 and HP‐β‐CD concentration of 0.1 mol/L was obtained with enantioselectivity (α) of 1.26, which was close to the theoretical maximum of 1.32 and performance factor (pf i ) of 0.036. The model was verified experimentally with excellent results. © 2011 American Institute of Chemical Engineers AIChE J, 2011