Comparison of vancomycin-immobilized chiral stationary phase with its derivative for enantioseparation of drugs in high-performance liquid chromatography

Vancomycin is a highly efficient glycopeptide antibiotic and a chiral separation material with excellent per-formance, whose structure contains multiple chiral sites. The change of structure can alter the binding perfor-mance between chiral stationary phase (CSP) and chiral drugs, ransforming the enantioseparation ability. Herein, vancomycin-immobilized CSP (V-CSP) and 3,5-dimethylphenyl isocyanate (DMP) derivatized vancomycin-immobilized CSP (D-V-CSP) were prepared. Both V-CSP and D-V-CSP were characterized through elemental analysis, fourier transform infrared (FT-IR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM), and then explored to separate chiral drugs in high-performance liquid chromatography (HPLC). After further optimizing the chromatographic separation conditions such as pH value, organic phase and flow rate, the enantioseparation of fluoxetine, labetalol, verapami, rosiglitazone, mirtazapine and chlorphen-amine maleate were obtained. Due to the change of structure of vancomycin, two as-synthesized CSPs exhibited different chiral recognition ability. Partial separation of labetalol (Rs = 0.682) and mirtazapine (Rs = 0.913) was achieved on V-CSP, which was better than that on D-V-CSP. The interaction force between the derivatized sta-tionary phase and the chiral drugs was significantly enhanced, therefore, on D-V-CSP chiral columns, baseline separation of fluoxetine (Rs = 2.149), rosiglitazone (Rs = 2.050) and chlorpheniramine maleate (Rs = 1.815) and partial separation of verapamil (Rs = 0.946) were achieved. Based on the above results, both V-CSP and D-V-CSP would successfully be applied in the separation of chiral drugs, and changing the structure of the stationary phase is beneficial to the improvement of chiral recognition ability for specific chiral drugs.

Automated summary

In this study, vancomycin-immobilized CSP (V-CSP) and derivatized vancomycin-immobilized CSP (D-V-CSP) were prepared and their separation abilities for chiral drugs were investigated. The results showed that changing the structure of the stationary phase can improve the chiral recognition ability for different chiral drugs.