Development and validation of stability-indicating RP-HPLC method for the determination of Nabumetone

A simple, precise, and accurate, isocratic, reversed RP-HPLC stability indicating method was developed and validated for determination of Nabumetone (Naphthyl acetic acid derivative). Isocratic RP-HPLC separation was achieved on Inert Sil ODS 3V (5μ, 25 cm× 4.6 mm, i.d.) column using mobile phase consisted of 0.47 g of tetrabutyl ammonium hydroxide sulphate (TBAH) dissolved in 1000 ml of a mixture of acetonitrile, water and triethylamine (290:710:1, v/v) adjusted with phosphoric acid to pH 6.5. Forced degradation studies were performed on bulk sample of Nabumetone using acid (2.0 N hydrochloric acid), base (1 N sodium hydroxide), oxidation (3.0% hydrogen peroxide), Dry heat (105°C) and Wet heat degradation (70°C reflux). Good resolution between the peaks corresponds to degradation products. The calibration curves of Nabumetone showed good linearity in the concentration range 2 –100 μg/ml with UV detection (239 nm). The correlation coefficients were better than 0.999. With limit of detection and quantification 0.29 and 0.87 μg /ml, respectively. The method has the requisite accuracy, selectivity, sensitivity and precision to assay degradation products resulting from the stress studies did not interfere with assay is thus stability-indicating.