ENANTIOMERIC SEPARATION OF KETAMINE-HYDROCHLORIDE IN PHARMACEUTICAL FORMULATION AND HUMAN SERUM BY CHIRAL LIQUID-CHROMATOGRAPHY

A commercially available microcrystalline cellulose triacetate (CA-1) chiral stationary phase was used for the enantiomeric resolution of ketamine [(+/-)-2-(2-chlorophenyl)-2-methylaminocyclohexanone]. A simple isocratic and direct liquid chromatographic resolution of racemic ketamine was accomplished -without derivatization, using pure ethanol as eluent with flow rate of 1 ml/min arid at 25-degrees-C. The enantiomeric elution order was determined by chromatographing the racemic ketamine and the separate enantiomers under the similar conditions. The capacity factor (k) for the first eluted peak was 2.2, stereochemical separation factor (alpha) and stereochemical resolution factor (R) were 2.32 and 3.38, respectively. This method has been applied to determine and identify ketamine enantiomers in human serum and a pharmaceutical dosage form.