Resolution of Enantiomers of Oxybutynin Chloride by Pressurized Capillary Electrochromatography

A method of pressurized capillary electrochromatography was proposed for the resolution of enantiomers of oxybutynin chloride using hydroxypropyl-β-cyclodextrin (16 g·L-1) as selective chiral agent. A mixed solution of acetonitrile and 5 mmol·L-1 phosphate buffer solution (60+40, by vol.) of pH 2.8 was used as mobile phase. Separation voltage of 18 kV and temperature of capillary column of 18 ℃ were chosen. Under the optimized conditions, the enantiomers of oxybutynin chloride were successfully separated within 14 min.