Enantioselective HPLC Analysis and In-vitro Kinetic Study Decomposition of Potential β-Blocker Drug in Guinea Pig Serum

Abstract

A method using off-line solid-phase extraction and liquid chromatography has been developed for the analysis of enantiomers of derivatives of aryloxyaminopropanol in guinea pig blood serum. The paper presents the results of HPLC enantioseparation of the derivative of aryloxyaminopropanol obtained by using of four chiral stationary phases [macrocyclic antibiotic (vancomycin, teicoplanin, teicoplanin aglycone, and methylated teicoplanin aglycone)] and the mixture of methanol/acetonitrile/acetic acid/triethylamine (45:55:0.3:0.2, v/v/v/v) as mobile phase for all tested stationary phases. The presence of saccharide moieties in the chiral stationary phase (vancomycin and teicoplanin chiral stationary phases) plays an important role, together with charge interactions and steric interactions, in the separation of enantiomers of derivatives of aryloxyaminopropanol. The in-vitro degradation studies of individual (R)-enantiomer and (S)- enantiomer in blood serum demonstrated a difference in the final concentration of the enantiomers after the incubation at 37°C. It was found that the rate constant of the (R)-enantiomer is lower than the (S)-enantiomer.

Keywords:

• β-blocker
• Degradation
• Enantiomers
• HPLC
• Serum

ACKNOWLEDGMENTS

Support from the Grant agency Slovak Republic (grants 1/0058/08, 1/4300/07), from Commenius University grant No. 304/07, and APVV project No. 20-035-205 is gratefully acknowledged. The authors thanks D.W. Armstrong for the donation of macrocyclic antibiotics chiral stationary phases.

Notes

¹The mobile phase for all the separations was methanol/acetonitrile/acetic acid/triethylamine (45:55:0.3:0.2, v/v/v/v). The flow rate was 0.8 ml/min. The detection wavelength was 247 nm and the operating column temperature was 25°C.

²V = Chirobiotic V (250 × 4.6 mm) column with vancomycin as chiral stationary phase, t₀ = 4.40 min.

³T = Chirobiotic T (250 × 4.6 mm) column with teicoplanin as chiral stationary phase, t₀ = 4.70 min.

⁴TAG = Chirobiotic TAG (250 × 4.6 mm) column with teicoplanin aglicon as chiral stationary phase, t₀ = 4.00 min.

⁵TAG-methylated = Chirobiotic TAG-methylated (125 × 4.6 mm) column with methylated teicoplanin aglicon as chiral stationary phase, t₀ = 2.42 min.

¹ Blood serum spiked with individual (S)-enantiomer and (R)-enantiomer and analysed separately.