DEVELOPMENT OF A VALIDATED RP-HPLC METHOD FOR THE DETERMINATION OF TIAGABINE AND ITS DEGRADED FORMS IN BULK AND PHARMACEUTICAL DOSAGE FORMS

Abstract

A simple and rapid isocratic reversed-phase high performance liquid chromatography (RP-HPLC) method was developed and validated as per International Conference on Harmonisation (ICH) and United States Pharmacopeia (USP) guidelines for analysis of tiagabine in the presence of its degradation products. The chromatographic separation was achieved on a Vision HT C18 column (150 mm × 4.6 mm, 5 μm) with mobile phase comprising of 11.5 mM sodium dihydrogen phosphate buffer (adjusted to pH 2.0 with orthophosphoric acid)/acetonitrile (50:50, v/v) at a flow rate of 1 mL/min and the UV detection wavelength was set at 254 nm. Stress degradation studies were performed as stated in ICH guidelines on tiagabine bulk drug using acid, base, oxidation, heat and light. The method was validated in accordance to system suitability, linearity and range, specificity, accuracy, precision, limit of detection (LOD), limit of quantitation (LOQ), and robustness. Tiagabine was found to degrade under acidic, photolytic, oxidative and thermal condition, but stable under basic hydrolysis condition. The developed method was found to be linear in the concentration range of 50-150 μg/mL (r2 = 0.9983) and the percentage recovery for the accuracy was 98.86-99.35%. The LOD and LOQ obtained were 31.93 μg/mL and 96.76 μg/mL, respectively while the %RSD for precision, robustness and stability studies were less than 2%. The degradation products formed from the stress degradation studies were well separated from tiagabine and hence the method could be regarded as stability indicating. The proposed method can be used in the analysis of tiagabine bulk drug and pharmaceutical formulations in quality control laboratories. Keywords: Tiagabine, RP-HPLC, Stress degradation studies, Validation.