Equivalent Method Development and Cross Validation of Pharmacopoeial Method of Montelukast Sodium

The purpose of this exploration research work article is to develop equivalent method and evaluate its equivalency (Cross validation) against pharmacopoeial method of Montelukast sodium for the evaluation and assessment of process related impurities i.e. Methyl MLK impurity in Montelukast sodium by HPLC method and its principles. The method mentioned in European Pharmacopoeia (EP) and United States Pharmacopoeia (USP) does not sufficiently separates impurity C and impurity D , as these impurities elutes under the main peak and the pharmacopoeial methods were also not able to detect the Methyl MLK impurity which is not listed in USP monograph. So our prime design of experiment is to develop of new high-performance liquid chromatographic (HPLC) method which eliminates the drawback of two pharmacopoeial methods and this proposed created strategy is fit for recognition and detection of Methyl MLK impurity and separation of all process related impurities of Montelukast sodium mentioned in EP and USP monographs. An efficient strategy screening and scouting in which various C-18 columns were tried and tested. LUNA C-18 column utilized in RP HPLC mode ended up being the phenomenal decision for the technique streamlining. The proportion of acetonitrile and trifluoroacetic acid (TFA) in water and in the mobile phase, column temperature, flow rate and diluents were considered as basic strategy boundary. The method developed equivalency was checked in terms of Specificity, LOD, Quantitation (LOQ), Precision, Linearity, Relative response factor (RRF), and Accuracy.