LC method for the determination of assay and purity of sibutramine hydrochloride and its enantiomers by chiral chromatography.

Two isocratic liquid chromatography (LC) methods have been developed for the purity estimation and quantitative determination of sibutramine HCl, using 4-chloro aniline and lovastatin as internal standards, respectively. The precision has been checked in terms of F-test variance ratio using latter method as reference. The ratio of variances of the two methods is close to unity, confirming their good precision. The correlation coefficient for linear regression is more than 0.999. The inter and intra-day precision is found to be < 1.3% RSD. The accuracy determined as relative mean error (RME) for the intra-day assay is +/- 1.7%. The enantiomeric separation of sibutramine by chiral chromatography method has been described also. This method is capable of separating the two enantiomers with a selectivity of 1.4 and a resolution of 4.0. Both methods are found to be stability indicating and useful in the quality control of the bulk material.