DEVELOPMENT AND VALIDATION OF STABILITY INDICATING METHOD FOR SIMULTANEOUS ESTIMATION OF FEBUXOSTAT AND DICLOFENAC POTASSIUM IN BULK AND TABLET DOSAGE FORM USING RP-HPLC

A novel method for the simultaneous estimation of Febuxostat and Diclofenac Potassium in combine dosage form was developed and validated by reverse phase high performance liquid chromatography. The determination was performed on an Inertsil C₁₈ column (100mm x 4.6 mm ID, 5µm particle size) and the mobile phase consisting a mixture of 0.01M Ammonium di-hydrogen phosphate buffer (pH adjusted to 5 with orthophosphoric acid) and Acetonitrile (60:40, v/v) was delivered at a flow rate of 1 ml/min and detector wavelength at 287nm. The retention time of Febuxostat and Diclofenac Potassium was found to be 2.303 and 4.105min respectively. The linearity for Febuxostat and Diclofenac Potassium was obtained in the concentration range of 10-60µg/ml and 25-150µg/ml with correlation coefficients (r²) of the regression equations greater than 0.9999 in all cases respectively. Results of assay, accuracy and precision were statistically evaluated as per ICH guidelines. Febuxostat and Diclofenac Potassium were subjected to acid and alkali hydrolysis, thermal and photolytic forced degradation. In the forced degradation study Febuxostat and Diclofenac Potassium showed maximum degradation in acid hydrolysis followed by less degradation in alkali hydrolysis, thermal and photolytic forced degradation. The developed method was simple, specific, sensitive, rapid, and economic and can be used for simultaneous estimation of Febuxostat and Diclofenac Potassium in bulk and their combined dosage form for routine analysis and stability studies