The separation of three basic drugs with carboxymethyl-poly-beta-cyclodextrin as chiral additive by capillary electrophoresis

Five cyclodextrin derivatives, namely phosphate ester beta-CD, carboxymethyl-beta-CD(CM-beta-CD), bis-[6-oxygen-(beta-carboxymethyl-succinic acid-4-ester)] beta-CD(F-CM-beta-CD), beta-CD polymer(P-beta-CD), carboxymethyl-poly-beta-CD (CD-P-beta-CD), were used as chiral selector for separation of three basic drugs, lobeline, thiopendonesodium, flunarizine by capillary zone electrophoresis (CZE). All the five cyclodextrins have chiral separation ability to lobeline. P-beta-CD and CM-P-beta-CD have chiral recognition to thiopentonesodium and flunarizine. The results indicate that via optimizing separation conditions by varying pH and the concentration of chiral selectors the three racemic drugs could be baseline separated with 2% P-beta-CD or 0.5% CM-P-beta-CD in the buffer of 30 mmol/L Tris-H3PO4. And the best resolution ranging from 4 to 35 with CM-P-beta-CD as chiral additive was obtained within 10 min. The results were much better than those reported in other references.