Simple Stability Indicating Methods for Metaxalone by RP-HPLC

S. Praveena, S. Muneer*, B. Mohammed Ishaq, Hindustan Abdul Ahad, Murali D 
PG department of Pharmaceutical Analysis, Balaji College of Pharmacy, Anantapur, AP, India

Abstract
A novel stability-indicating high-performance liquid chromatographic assay method was developed and validated for Metaxalone in the presence of degradation products generated from forced decomposition studies. Metaxalone is a skeletal muscle relaxant. The method was based on the separation of Metaxalone on Hypersil BDS C₁₈ (150 mm x 4.6 mm, 5 μm) column using isocratic mobile phase Methanol: water (90:10, v/v) with a flow rate of 1 ml/min and the UV detection at 279 nm. And the column temperature was maintained at ambient condition. The linearity of the method was found to be 10-60 µg/ml the mean % RSD was found to be 1.67 and 1.86. Forced degradation studies have been carried out for metaxalone. Sample was exposed to various stress conditions like, treatment with acid (0.1 N HCl), alkali (0.1 N NaOH), heat (60ᵒC for 30 min) and peroxidation (H₂O₂) effects has been determined and degradation products were studied. Sample was degraded to 75-85 % in acid, alkali and peroxidation treatment. But found to be stable for heat treatment. The method was validated as per ICH guidelines. All the validation parameters were found to be within the predetermined limits. This shows that the proposed method was sensitive and selective for the determination of stability indicating assay of MET in bulk and its tablet dosage form.
Keywords: Metaxalone, ICH guidelines, stability-indicating and Methanol.