title: Enantiospecific assay of citadiol--a key intermediate of escitalopram by liquid chromatography on Chiralpak AD-H column connected with UV and polarimetric detectors in series.
abstract: A simple, rapid, selective and reproducible LC method for separation and quantitative determination of citadiol (CTD), a key intermediate of escitalopram has been developed. An optimum resolution > 3.0 was achieved on Chiralpak AD-H (250 mm x 4.6 mm); 5 microm column connected with UV and polarimetric detectors in series. The effects of organic modifiers, viz., methanol, ethanol, n-propanol and 2-propanol on enantioselectivity were evaluated. The limits of detection (LOD) and quantification (LOQ) were 0.02 microg/ml, 0.03 microg/ml and 0.07 microg/ml, 0.10 microg/ml for R-CTD and S-CTD enantiomers, respectively. The linearity of the method was studied in the range of 0.07-300 microg/ml and 0.1-300 microg/ml for R-CTD and S-CTD, respectively and the r2 was > or = 0.9999. The inter- and intra-day assay precision was less than 0.74% (%R.S.D.) and the recoveries were in the range 99.68-100.72% with %R.S.D. < 0.49%.
authors.affiliation: HPLC/UV Group, Division of Analytical Chemistry, Discovery Laboratory, Indian Institute of Chemical Technology, Hyderabad 500007, India. rnrao@iictnet.org
authors.forename: R
authors.initials: R
authors.lastname: Nageswara Rao
authors.forename: A
authors.initials: A
authors.lastname: Narasa Raju
mesh_terms: D002138:Calibration; D002851:Chromatography, High Pressure Liquid; D015283:Citalopram / Q000032:analysis*; D007202:Indicators and Reagents; D009570:Nitriles / Q000032:analysis*; D011134:Polysaccharides / Q000032:analysis; D012015:Reference Standards; D015203:Reproducibility of Results; D013056:Spectrophotometry, Ultraviolet; D013237:Stereoisomerism
chemical_list: D007202:Indicators and Reagents; D009570:Nitriles; D011134:Polysaccharides; D015283:Citalopram; C517833:citadiol