L. Dou et al., CHIRAL HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY METHODOLOGY FOR QUALITY-CONTROL MONITORING OF DEXFENFLURAMINE, Journal of chromatography, 679(2), 1994, pp. 367-374
The objective of this study was to measure the concentration of d-fenf
luramine . HCl (the desired product) and l-fenfluramine . HCl (enantio
meric impurity), in the final pharmaceutical product, in the possible
presence of its isomeric variants. Sensitivity, stability and specific
ity were enhanced by derivatizing the analytes with 3,5-dinitrophenyli
socyanate utilizing a Pirkle chiral recognition approach. Analysis of
the calibration curve data and quality assurance samples showed an ove
rall inter-assay precision of 1.78 and 2.52%, for d-fenfluramine . HCl
and l-fenfluramine, with an overall intra-assay precision of 4.75 and
3.67%, respectively. The minimum quantitation limit was 50 ng/ml, hav
ing a minimum signal-to-noise ratio of 10, with relative standard devi
ations of 2.39 and 3.62% for d-fenfluramine and l-fenfluramine. The me
thod is capable of accurately and consistently determining as low as 0
.01% l-fenfluramine in the d-fenfluramine final pharmaceutical product
.