VALIDATED IC METHOD FOR DETERMINATION OF CONTENTS OF RESIDUAL AMINO GUANIDINE IN LAMOTRIGINE DRUG SUBSTANCES WITH SUPPRESSED CONDUCTIVITY DETECTOR

Abstract

This paper describes a validated method for the quantification of amino guanidine in Lamotrigine drug substances and their intermediates using Ion Chromatography (IC), with out any dervitization process. It was analysed using a Ion pac CS17 250 x 4.0 mm column with guard column CG17 50 x 4.0 mm, with a flow rate of 1.5 mL/min with injection volume of 20µL with conductivity detection with CSRS 300 x4.0mm suppressor with suppressor current 40 mA and having only 10 minutes runtime with methanol as diluent. It has the mobile phase of 20% v/v Milli-Q-Water and 80% v/v of 10 mM methane sulphonic acid solution.  The method is validated for its Specificity, Precision, Accuracy, Linearity, Ruggedness and solution stability. Aminoguanidine is linear from 1 μg/ml to 25 μg/ml with correlation coefficient 0.9999. Limit of Quantitation of the method is 1 μg/ml and Limit of Detection is 0.3 μg/ml.