Abstracto

Stability indicatingmethod for estimation of Amlodipine besylate by RP-HPLC in tablet dosage formand characterization of the oxidation impurity of amlodipine besylate

Pritam S.Jain, ManishK.Patel, Sanjay J.Surana

A simple, specific, accurate and precise stability indicating Reverse Phase High Performance Liquid Chromatographic method was developed for estimation ofAmlodipine besylate in tablet dosage formon RP C18 BDS column (250mm×4.6 mm, 5µm) with a mobile phase consisting of A: Triethylamine (pH 3.0) adjusted with ortho phosphoric acid, B:ACN, with a timed gradient program of T/%B: 0/30, 7/70, 8/30, 10/30 with a flow rate of 1.4 ml/min, UV detection at 236 nmwas used. The retention time forAmlodipine besylate was found to be 4.5min. Proposedmethod was validated for precision, accuracy, linearity, range, robustness, ruggedness and force degradation study. The calibration curve ofAmlodipine besylate was linear over the range of 12.5-37.5 µg/ml. The method was found to be sensitive with limit of detection was determined 0.16 and limit of quantitation was determined 0.49 µg/ml. The oxidative degraded product ofAmlodipine besylate formed was investigated by electrospray ionization (ESI) timeof- flightmass spectrometry, NMR and IR spectroscopy. The found unknown impurity related to oxidative degradationwas 2, 6-dimethyl-3-Ethoxycarbonyl-5-Methoxycarbonyl 1, 4-Dihydropyridine.