BIOEQUIVALENCE STUDIES OF MARKETED CLOZAPINE TABLETS BY USING OPTIMIZED VALIDATED LIQUID CHROMATOGRAPHIC METHOD

Abstract

Objective: A simple, selective, precise and accurate method was developed for the estimation of Clozapine by RP-HPLC technique.Methods: Chromatographic conditions used are stationary phase, Phenomenex BDS (150 mm x 4.6 mm, 5µ), Mobile phase was methanol and water in (80:20) ratio and flow rate was maintained at 1.0 ml/min, column temperature was set at 25 °C, detection wavelength was 240 nm, and diluent was mobile phase. These conditions were finalized for the optimized method.Results: Linearity study was carried out between 10-60 µg/ml, the R2 value was found to be as 0.995. Precision was found to be as follows for system precision 1.052, method precision 1.662, and intraday precision 1.02 and for interday precision 0.93. The % Recovery was found to be 98.60%. LOD and LOQ were found to be 2.7 µg/ml and 8.4 µg/ml respectively. By using the above method assay of the marketed formulation was carried out and the % purity was found to be 99.28 %. Stability studies of Clozapine were done, in all conditions degradation was found to be within the acceptable range.Conclusion: The current validated method was finally applied in bioequivalence studies of four different brands of Clozapine by using dissolution apparatus and percentage drug release was found to be 99.48%, it was within the acceptable limit (NLT 85 %) as per USP.