Determination of oxcarbazepine and its related substances using UHPLC method with UV detection

A simple and rapid ultra - high performance liquid chromatographic (UHPLC) method for the separation and determination of oxcarbazepine and its related substances in tablets, was developed. Chromatographic separation of oxcarbazepine from its related substances (degradation and by-products) was achieved on a reversed phase C18 column (Pinnacle DB C18, RESTEK, 100 x 2.1 mm, 1.9 μm particle size) using gradient program with water (as mobile phase A) and acetonitrile (as mobile phase B), at a flow rate 0.5 mL min-1 and UV detection at 254 nm. The column temperature was 30°C.The method has good selectivity towards oxcarbazepine and its related substances. The accuracy of the method for oxcarbazepine assay, expressed as mean recovery was 101.8 %, and of the method for quantification of degradation products was 95.9 % - 103.3 %. Limit of quantification for oxcarbazepine and its degradation products ranged from 0.60 μg mL-1 to 1.30 μg mL-1. The linearity range for oxcarbazepine assay was from 2.4 to 3.60 mg mL-1 (R2=0.999). Mean value for oxcarbazepine assay from the tablets was 299.92 mg (label claim 300 mg). The method can be used for routine analysis and the quality control of oxcarbazepine drug substance and its formulated products