RESOLUTION OF ENANTIOMERS OF TROPICAMIDE BY REVERSED-PHASE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY USING HYDROXYPROPYL-BETA-CYCLODEXTRIN AS CHIRAL MOBILE-PHASE ADDITIVE

Hydroxypropyl-beta-cyclo dextrin (HP-beta-CD) was used as an effective chiral mobile phase additive for the HPLC resolution of the enantiome rs of tropicamide. The HP-beta-CD is more soluble in water and hydro-o rganic solvents than the native-beta-cyclodextrin. The separation of t he tropicamide enantiomers was influenced by a combination of hydropho bic and hydrogen bonding interactions. A baseline separation (Rs>1.5) was achieved for the enantiomers under isocratic conditions on a cyano propyl column with 10:90 v/v acetonitrile-aqueous 0.1% triethylammoniu m acetate buffer pH 4.0 containing 10 mM HP-beta-CD. The flow rate was 1.0 mL/min with detection at 255 nm. The effect of mobile phase compo sition, concentration of HP-beta-CD, and the pH and type of buffer on peak shape, resolution and retention factors of the enantiomers were i nvestigated.