An isocratic, reversed-phase liquid chromatographic (RP-LC) method was developed for the quantitative determination of oxcarbazepine, used in the treatment of epilepsy. This method can be also employed for the related substance determination in bulk samples. Forced degradation studies were performed on bulk sample of oxcarbazepine using acid (1.0 N hydrochloric acid), base (0.1 N sodium hydroxide), oxidation (3.0% hydrogen peroxide), heat (80°C) and photolytic degradation. The chromatographic method was Þne tuned using the samples generated from forced degradation studies. Good resolution between the peaks corresponds to degradation products and the analyte was achieved on Zorbax Eclipse XDB-C18 250 X 4.6 mm, 5 µm column. The mobile phase consists of a mixture of 0.005 M KH2PO4: Methanol: Acetonitrile (70:05:25% v/v/v) efß uent was monitored at 215 nm using PDA detector. The method was linear over the concentration range of 1-1000 µg/ml (r = 0.9999) with a limit of detection and quantitation 0.1 and 0.3 µg /ml, respectively. The method has the requisite accuracy, selectivity, sensitivity and precision to assay oxcarbazepine in bulk form and pharmaceutical dosage forms. Degradation products resulting from the stress studies did not interfere with the detection of oxcarbazepine and the assay is thus stability-indicating.
Key words: Assay, oxcarbazepine, recovery studies, speciÞ city, stress studies.