Method Development and Validation for Simultaneous Estimation of Metamizole Sodium and Pitofenone HCl by a Stability Indicating RP-HPLC.

A simple, selective, rapid and precise RP-HPLC has been developed for the simultaneous estimation of Metamizole sodium and Pitofenone HCl in presence of Fenpiverinium bromide of combined Pharmaceutical dosage forms. The Inertsil ODS 3V C-18 Column was used for Metamizole sodium and Pitofenone HCL separation. The Mobile phase used was sodium dihydrogen phosphate buffer: Methanol,(0.05M, pH 5.0), (53:47 v/v) at a flow rate of 1ml/min at 286nm. The calibration curves was linear at a concentration range of 700.90 μg/ml to1301.73 μg/ml and 7.01�g/ml to 13.01μg/ml with its regression coefficient (r²=0.9992 and 0.9995) for Metamizole sodium and Pitofenone HCl respectively was obtained. The LOD and LOQ was found to be in the range of 21.6174 μg/ml and 65.507 μg/ml for Metamizole sodium and 0.1701μg/ml and 0.5155 μg/ml for Pitofenone HCl respectively. The method is highly sensitive and successfully applied for determination of Metamizole sodium and Fenpiverinium bromide in tablet dosage forms.