DEVELOPMENT AND VALIDATION OF THE PROCEDURE FOR QUANTITATIVE DETERMINATION OF IMPURITIES IN TABLETS “RANOLAZIN-NAN”

The article presents the results of the research on the development of the procedure for determining related impurities by high-performance reversed-phase chromatography in the tablets “Ranolazin-NAN”. The conditions for samples preparation of ranolazine tablets, optimal conditions for the gradient mode of chromatography were selected using Zorbax Eclipse Plus C18 column: eluent A - 0,1% triethylamine buffer with pH 6,0 ± 0,1 (diluted with orthophosphoric acid) and acetonitrile in a ratio 70:30 v / v and eluent B - acetonitrile. The effect of pH medium (2,0, 6,0 and 9,0) on the efficiency of the column while studying the solutions of ranolazine and identified impurities was established. The suitability of the chromatographic system was proven and the specificity of the method for determining unidentified and identified impurities was proven. Linearity in the entire range of the procedure usage (from the quantitation limit to 125% (of the content of a single impurity)), correctness as well as precision at the level of reproductivity and intermediate precision, and the stability (robustness) of the method with small changes in the flow rate and column temperature were proven for the procedure of related impurities determination in Ranolazin-NAN tablets.