Simultaneous Estimation of Metaxalone and Diclofenac Potassium in Combined Dosage form by High Performance Liquid Chromatography MethodAuthor(s): Koshish B. Gabhane
A simple, sensitive, rapid, and reproducible RP-HPLC chromatographic method has been developed for the estimation of diclofenac and metaxalone in pharmaceutical formulation. Chromatography was carried out on an isocratic system of JASCO with Inertsil C-18 (4.6 x 250 μm, i.d 10 μm) using a mixture of acetonitrile, methanol and water as mobile phase at flow rate of 1 mL/min and detection was done at 234 nm. The retention time for metaxalone and diclofenac potassium was found to be 3.70 min and 2.03 min, respectively. The results obtained in the proposed method are in good agreement with labeled amounts, when marketed pharmaceutical preparations were analyzed. The method was validated for parameters like accuracy, precision, ruggedness, specificity, linearity and range according to ICH guidelines. The mean recoveries from tablet formulations were between 99-101%. The detector responses were found to be linear in the concentration range of 80-120 % of the test concentration of each drug.