Stress degradation studies on aliskiren and the development of a sensitive stability-indicating MEKC method

Abstract

Summary.A sensitive, fast, and stability-indicating micellar electrokinetic chromatographic (MEKC) method was developed and validated for the analysis of aliskiren (ALI) in tablets using nimesulide as internal standard (IS). Optimal conditions for the separation of ALI and its degradation products were investigated. The method employed 60 mM Tris buffer and 50 mM anionic detergent sodium dodecyl sulfate (SDS) solution at pH 9.8. MEKC method was performed on a fused-silica capillary (50 μm id; effective length, 40 cm). The capillary temperature was maintained at 35°C, and the applied voltage was 30 kV, with detection by photodiode array (PDA) detector set at 204 nm. The method was validated in accordance with the International Conference on Harmonisation (ICH) requirements. The stability-indicating capability of the method was established by enforced degradation studies combined with peak purity assessment using PDA detection. The method was linear over the concentration range of 5-150 μg mL −1 (r 2 = 0.9996) of ALI. Intraday and interday precision and accuracy evaluated by relative standard deviation, respectively, were lower than 2%. The limit of detection was 1.31 µg mL −1 . The method proved to be robust by a one-variable-at-a-time evaluation. The proposed MEKC method was successfully applied for the quantitative analysis of ALI in tablets to support the quality control.