Novel chiral composite membrane prepared via the interfacial polymerization of diethylamino-beta-cyclodextrin for the enantioseparation of chiral drugs

A novel chiral thin-film composite polyamide (CTFC) membrane was fabricated by using in situ interfacial polymerization. The diethylamino-beta-cyclodextrin (EDA-β-CD) monomer was synthesized as the chiral selector and interfacially polymerized with trimesoyl chloride (TMC) to fabricate the CTFC membrane on the surface of a commercial cellulose acetate (CA) membrane. The intrinsic properties of the chiral EDA-β-CD-TMC/CA membrane were investigated by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Several parameters, namely, EDA-β-CD concentration, interfacial polymerization (IP) time, and curing time were varied. At the optimal conditions, the water permeate flux was 35.7 L m−2 h−1 and the rejection of BSA was 80.7%. For the enantioseparation, various chiral drugs such as warfarin, ibuprofen, nefopam, ketoprofen and tryptophan were separated using chiral EDA-β-CD-TMC/CA membranes. The results indicate that the percent enantiomeric excess (e.e%) was above 9.29 ± 3.21% for warfarin, 3.77 ± 0.23% for ibuprofen and 27.2% for tryptophan. Additionally, the as-prepared membrane was relatively stable in a wide pH range, so that it may be used for industrial production.