Indirect synchronous fluorescence spectroscopy and direct high‐performance thin‐layer chromatographic methods for enantioseperation of zopiclone and determination of chiral‐switching eszopiclone: Evaluation of thermodynamic quantities of chromatographic separation

Abstract

Economic and enantioselective synchronous fluorescence spectroscopy and high-performance thin-layer chromatography methods have been developed and validated as per ICH guidelines for the separation of zopiclone enantiomers using L-(+)-tartaric acid as a chiral selector, followed by determination of the chiral-switching eszopiclone. Synchronous fluorescence spectroscopy was successfully applied for chiral recognition of R & S enantiomers of zopiclone at Δλ = 110 nm based on creating of diastereomeric complexes with 0.06M tartaric acid in an aqueous medium containing 0.2M disodium hydrogen orthophosphate. Synchronous fluorescence intensities of eszopiclone were recorded at 296 nm in concentration range 0.2-to 4-μg/mL eszopiclone. High-performance

Economic Electrochemical Sensors for the Determination of Eszopiclone in Pharmaceutical Formulation with Greenness Profile Assessment

“…United States Pharmacopoeia [4] recommends an HPLC assay of EZP achieved on octadecyl silane column (C18, 4.6-mm × 15.0-cm, 5-μm packing) with UV detection at 303 nm. Some analytical methods have been reported in literature for EZP determination, these include UV spectrophotometric [5][6][7][8], spectrofluorometric [9], HPLC [10][11][12][13][14][15][16][17][18][19][20], UPLC [13,21,22] and TLC [9,23] methods. To the best of our knowledge no potentiometric techniques has been previously published for the determination of EZP.…”