Preparation and characterization of a chiral molecularly imprinted polymer with a novel functional monomer for controlled release of S-sulpiride

Abstract

A novel molecularly imprinted polymer (MIP) with chiral recognition affinity to S-sulpiride (S-SUL) enantiomer was prepared by using newly synthesized N-acryloyl-tryptophan (ATrp) as function monomer, S-SUL as the template molecule, and ethyleneglycol dimethacrylate (EGDMA) as the cross linker. Under the optimized synthesis conditions, the MIP was synthesized by bulk polymerization according to the molar ratio of 1:4 of S-SUL to ATrp, and structurally characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM) and laser particle analysis. The results illustrated that the MIP offered uniform, loose and porous structure. The adsorption performance of the MIP was evaluated by the isotherm and kinetic models, and the adsorption isotherm conformed to the Freundlich model. The maximum adsorption capacity, selectivity factor and enantioselectivity coefficient to S-SUL were respectively 226.2389 µmol/g, 2.34 and 11.66. Based on the chiral recognition specificity, the drug release experiments demonstrated that the MIP as controlled and sustained release carrier could inhibit the release rate of S-enantiomer compared to the tablet without the MIP, exhibiting the potential of the MIP synthesized in chiral drug delivery.

Keywords: Chiral drug release; Chiral recognition; Molecularly imprinted polymer; N-acryloyl-tryptophan; Novel functional monomer; Sulpiride.