A NEW STABILITY INDICATING UPLC METHOD DEVELOPMENT AND VALIDATION FOR THE SIMULTANEOUS ESTIMATION OF DULOXETINE AND MECOBALAMIN IN BULK AND IN ITS DOSAGE FORMS

Objective: The objective of the work is to develop and validate a stability indicating, new, simple, highly sensitive RP-UPLC method for simultaneous estimation of Duloxetine and Mecobalamin in bulk and in its dosage forms. Methods: The Method was developed and excellent chromatographic separation was obtained on a reversed-phase Acquity UPLC BEH C18 (1.0 × 100 mm, 1.7 µm) column using an isocratic elution mode by the mobile phase using Methanol: Water (55:45). The flow rate of the mobile phase was 1.0mL/min and the total run time was 10 minutes. UV-Spectroscopic detection at a wavelength of 320 nm was performed and the column oven temperature was maintained at 400C. The analytical procedure was validated by assessing the specificity, linearity, precision, robustness, ruggedness, limit of detection, limit of quantification and accuracy as per ICH guidelines.Results: The retention times in the standard solution having the concentration of 3 μg/ml and 75 μg/ml of Duloxetine & Mecobalamin were found to be around 4.320 and 5.320 min respectively. The percentage purity values are 99.71 % w/v and 99.02% w/v. Calibration plots were linear (r2 > 0.999) over the concentration range of 1.5 – 5.25 μg/ml and 37.5 – 131.25 μg/ml, the percentage recovery was found to be 99.74% and 99.82% for Duloxetine & Mecobalamin respectively. %RSD for system precision, method precision, robustness and ruggedness was found to be with in 2. The LOD 0.04791 µg/mL for Duloxetine and 0.4496 µg/mL for Mecobalamin. The LOQ was found to be 0.1452 µg/mL for Duloxetine and 1.3625 µg/mL for Mecobalamin. Conclusion: The method represents a fast analytical procedure for the simultaneous quantification of Duloxetine & Mecobalamin. The developed method requires lesser analysis time and less mobile phase consumption. No interference from any component of pharmaceutical dosage form was observed. Validation studies revealed that the method is specific, rapid, reliable, accurate, robust and reproducible. The method is amenable to the routine analysis of large numbers of samples with good precision and accuracy. The most striking feature of this method is its simplicity and rapidity, non-requiring-consuming sample preparation such as extraction with solvents, heating, degassing which are needed for HPLC procedure