SEPARATION OF LISINOPRIL AND ITS RSS DIASTEREOISOMER BY MICELLAR ELECTROKINETIC CHROMATOGRAPHY

Diastereoisomer separation of pharmaceuticals having several chiral ce nters by capillary electrophoresis is exemplified by the separation of lisinopril (SSS) (an inhibitor of angiotensin converting enzyme) from its RSS diastereoisomer. Using micellar electrokinetic capillary chro matography (MECC), excellent resolution between the two diastereoisome rs was achieved by using a bile salt, sodium cholate, as the surfactan t in electrolyte under optimized pH, organic content and temperature c onditions. The RSS compound eluted earlier than the SSS compound. A go od separation was also achieved by the use of sodium dodecyl sulfate ( SDS) as a surfactant in electrolyte, but the eluting sequence was reve rsed, resulting from the different hydrophobic/hydrophilic nature of t he two surfactants.