HPLC Separation Of Drug Enantiomers Using Chiral Mobile Phase Additive

With the intensive study of the drug enantiomers separation using chiral mobile phaseadditives (CMPA), cyclodextrin derivatives become an important chiral additives for theirgood stereoselectivity and stability. Cyclodextrin,s water solubility, hydrophobicity andstereoselectivity were changed by the introduction of other groups on the surfacehydroxyl,thereby the chiral selectivity was enhanced. In recent years, they were used morewidely in the study of chiral drugs separation.In this paper, carboxymethyl-β-cyclodextrin (referred to as CM-β-CD) was synthetisedby the β-CD and chloroacetic acid under the alkaline conditions. It was characterized by IRspectroscopy,1H NMR and its degree of substitution was determined. Using HPLCperformance liquid chromatography,the chiral separation of vasopressor drugs Etilefrinehydrochloride and the antihypertensive drugs Bisoprolol were studied in C18column withCM-β-CD as chiral mobile phase additive. The influence of concentration of mobile phaseadditives, organic modifier content, pH, concentration of triethylamine and flow rate on theseparation were studied systematiclly. The best chromatographic separation conditions ofEtilefrine hydrochloride and bisoprolol enantiomers were obtained.The experimental results show that the Etilefrine hydrochloride enantiomer resolutionwas1.46by using acetonitrile, methanol, water (15:60:25, V/V/V) as the mobile phase,containing0.6g·L-1CM-β-CD and0.14%(V/V) triethylamine,the pH value was3.9, at the flowrate of0.20mL·min-1, the UV detection wavelength was214nm. The bisoprolol enantiomerresolution was1.89. The optimum condition is using acetonitrile, methanol, water(20:67:13,V/V/V) as the mobile phase. containing0.5g·L-1CM-β-CD and0.03%(V/V)triethylamine,the pH value was4.1, at the flow rate of0.30mL·min-1, the UV detectionwavelength was seted at223nm.