Application of Design of Experiment in Design, Development and Optimization of Stability Indicating RP-HPLC Method for Simultaneous Determination of Montelukast Sodium and Rupatadine Fumarate in Bulk and Formulation

Design of Experiment assisted stability indicating RP-HPLC wasdesigned, developed and optimized using response surface methodology for simultaneous determination of Montelukast sodium and Rupatadine fumarate. Separation was achieved using Acetonitrile: Phosphate buffer (75:25) v/v with pH adjusted to 4.0, flow rate of 1 ml/min with UV detection at 246 nm on RP-C18 column. Stress degradation studies were performed as per scientific guidelines. Method was validated in accordance with regulatory requirements. Results obtained in validation were found to be within specified limit. Montelukast was eluted at 3.99 min and Rupatadine was eluted at 13.25 min respectively. All stress degradation products are very well resolved from drug peak which indicate suitability indicating nature of the developed method. Design of Experiment technique can help in fast and economical optimization of mobile phase which in turn will save time for method development. The developed method is, accurate, sensitive which can be utilized as stability indicating method for identification of degradation products in routine analysis of the drug.