Elham A. Taha¹, Nahla N. Salama¹ and Shudong Wang²

¹National Organization for Drug Control and Research (NODCAR), 6-Abu Hazem Street, Pyramids Ave. P.O. Box 29, 35521 Giza, Egypt. ²School of Pharmacy and Centre for Biomolecular Sciences, University of Nottingham, University Park, NG7 2RD, U.K.

Abstract

Two sensitive and validated methods were developed for determination of a racemic mixture citalopram and its enantiomer S-(+) escitalopram. The first method was based on direct measurement of the intrinsic fluorescence of escitalopram using sodium dodecyl sulfate as micelle enhancer. This was further applied to determine escitalopram in spiked human plasma, as well as in the presence of common and co-administerated drugs. The second method was TLC densitometric based on various chiral selectors was investigated. The optimum TLC conditions were found to be sensitive and selective for identification and quantitative determination of enantiomeric purity of escitalopram in drug substance and drug products. The method can be useful to investigate adulteration of pure isomer with the cheap racemic form.