DETERMINATION OF FENFLURAMINE ENANTIOMERS IN PHARMACEUTICAL FORMULATIONS BY CAPILLARY ZONE ELECTROPHORESIS

Capillary zone electrophoresis has been used for the enantiomeric separation of racemic ortho-fenfluramine and meta-fenfluramine employing a phosphate buffer at pH 2.5 added with cyclodextrins. The cyclodextrin type and concentration strongly influenced the chiral resolution. The uncharged beta-cyclodextrin polymer gave enantiomeric resolution of both ortho and meta isomers, while gamma-cyclodextrin was a good chiral selector for only ortho-fenfluramine; heptakis-2,3,6-tri-O-methyl-beta-cyclodextrin permitted base line separation of meta-fenfluramine enantiomers but only partial resolution of racemic ortho-fenfluramine, The optimized electrophoretic method was applied to the quantitative analysis of 1-meta-fenfluramine (minor component in the mixture) and d-meta-fenfluramine in a commercial pharmaceutical formulation. Good reproducibility for migration time and corrected peak areas (R.S.D. < 0.8 % and < 1.2 %, respectively) was achieved and the presence of the minor component of the mixture was found to be in accord to previous determinations performed by other analytical methods.