Development and validation of a chiral liquid chromatographic method for determination of S-isomer in cinacalcet API

A reversed phase enantioselective high performance liquid chromatographic method was developed and validated for determination ofS-enantiomer in Cinacalcet drug substance. The enantiomers of Cinacalcet were resolved on a Chiralcel-OJH (250mmx4.6mm, 5microns) column using a mobile phase system containing n-Hexane, ethanol and n-butyl amine (90:10:1). The resolution between enantiomers was found to be more than 2.0. The retention times of S-enantiomer and Cinacalcet were found to be 7.50 and 9.63 min, respectively. The limit of detection and limit of quantification of S-enantiomer were found to be 0.014 and 0.042 respectively. The proposed method was validated with respect to linearity, accuracy, precision, specificity, and robustness. Recovery of S-isomer was found to be 99.9%.Correlation coefficient between detector response and linearity concentration in the range of LOQ to 250% was found to be 0.99. The sample solution and mobile phase were found to be stable for at least 48 hours. The final optimized method was successfully applied for separation of S-enantiomer from Cinacalcet drug substance and proven to be reproducible and accurate for quantitative determination of S-enantiomer in bulk drugs.