Validated RP- HPLC Method for Simultaneous Estimation of Metaxalone and Diclofenac potassium in Combined Dosage Form

A simple, accurate, precise, specific, sensitive, reproducible and Reliable RP- HPLC Method was developed for Quantitative Estimation of Metaxalone and Diclofenac potassium in Pharmaceutical Dosage Form. The developed RP- HPLC method with the mobile phase Methanol: Water (80: 20) and Qualisilgold-C18 (250Χ4.6mm, 5μm particle size) as stationary phase with a flow rate of 1.0 mL/minute by using λmax 275nm and PDA detector. Proposed method was found to be linear in the concentration range of 8.0 to 80.0 μg/mL for Metaxalone and 1.0 to 10.0 μg/mL for Diclofenac potassium respectively, and the correlation coefficient was found to be 0.9991 for both the drugs. Precision study showed that the % RSD was within the range of acceptable limits (< 2), and the % Recovery was found to be in the range of 99.29%-101.28% for Metaxalone and 99.98%-102.45% for Diclofenac potassium. The proposed method has been validated as per ICH guidelines.