STABILITY INDICATING HPLC METHOD FOR THE DETERMINATION OF ESLICARBAZEPINE ACETATE AND ITS IMPURITIES IN BULK DRUGS AND PHARMACEUTICAL DOSAGE FORMS

Abstract

A new stability-indicating gradient reverse phase high-performance liquid chromatographic (RP-HPLC) method was developed for the quantitative determination of Eslicarbazepine acetate (antiepileptic drug) in bulk drugs and pharmaceutical dosage forms along with its impurities and degradation products. The method was developed using Zorbax SB C-18 (150 mm × 4.6 mm, 3.5 µm) column with mobile phase containing a gradient mixture of solvents A and B. The solvent A contains a mixture of 0.01 M KH2PO4 and Methanol in the ratio of 80:20, and the solvent B contains a mixture of Acetonitrile, Methanol, and Water in the ratio 75:5:20 (v/v). Eslicarbazepine acetate was subjected to the stress conditions of oxidative degradation, acid, base, neutral hydrolysis, and thermal and photolytic degradation. Eslicarbazepine acetate was found to degrade significantly in acid, base, neutral hydrolysis, and oxidative stress conditions. The degradation products were well resolved from main peak and its impurities within 20 min run time, proving the stability-indicating power of the method. The developed method was validated as per International Conference on Harmonization (ICH) guidelines with respect to specificity, linearity, accuracy, precision, and robustness. This method was also suitable for the assay determination of Eslicarbazepine acetate in drug substance and drug product.