Die Pharmazie is published by IMR Press from Volume 81 Issue 1 (2026). Previous articles were published by another publisher under the CC-BY licence, and they are hosted by IMR Press on imrpress.com as a courtesy and upon agreement.
Enantiomeric separation of S-zopiclone and its R-enantiomer in bulk drug samples by validated chiral RP-HPLC
S. Sangaraju 1, M. Lakshmi Kanth 1, B.M. Rao 2, N. Someswararao 3
Affiliations
Article Info
1 Analytical Research, Custom Pharmaceutical Services, Dr. Reddy's Laboratories Ltd., Visakhapatnam, India
2 Andhra University, Visakhapatnam, 530 003, India, Email: drbmrao@hotmail.com
3 Andhra University, Visakhapatnam, India
Abstract
A simple and selective isocratic chiral RP-HPLC method was developed forthe enantiomeric purity determination of S-zopiclone and the quantitative determination of R-zopiclone in bulk drug samples. Enantiomeric separation was achieved using Chiralcel OD-RH 150 × 4.6 mm, 5 μm particle size column at 25 °C using a mobile phase of 10 mM ammonium acetate and acetonitrile in ratio of 60:40 (v/v) as mobile phase at a flow rate of 1.0 mL.min–1 and UV detection at 306 nm. The method resolves the R-zopiclone and S-zopiclone with resolution (Rs) greater than 1.6. The limit of detection (LOD) and limit of quantitation (LOQ) of the R-enantiomerwere 0.12 μg. mL–1 and 0.40 μg. mL–1 respectively, for 10 μL injection volume. The percentage RSD of the peak area of six replicate injections of R-zopiclone at LOQ concentration was 4.6. The percentage recoveries of R-enantiomer from S-zopiclone were ranged from 97.3 to 99.8. Developed method was found to be selective in presence potential impurities. The developed chiral RP-HPLC method was validated with respect to precision, linearity, accuracy, robustness and ruggedness. The test solution and mobile phase was found to be stable up to 24 h after preparation.