Table of Contents
ISRN Medicinal Chemistry
Volume 2013, Article ID 178269, 9 pages
Research Article

New Stability Indicating Method for Quantification of Impurities in Amlodipine and Valsartan Tablets by Validated HPLC

1Quality and Analytical Development Department, InvaGen Pharmaceuticals, Inc., Hauppauge, NY 11788, USA
2Department of Chemistry, Sri Krishnadevaraya University, 515003 Anantapur, India

Received 31 March 2013; Accepted 8 May 2013

Academic Editors: Y. Onuki and U. G. Spizzirri

Copyright © 2013 Rama Joga Venkata Eranki et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


A stability indicating LC method was developed for simultaneous determination of amlodipine and valsartan in pharmaceutical dosage form. Efficient chromatographic separation was achieved on C8 stationary phase with simple combination of mobile phase-A (70 : 20 : 10 v/v/v of water : acetonitrile : methanol with 2 mL of Octylamine adjusted the pH to 2.50 + 0.05 with orthophosphoric acid) and mobile phase-B (Acetonitrile) delivered in gradient mode. Quantification was carried out using ultraviolet detection at 240 nm at flow rate of 1.0 mL/min with Injection Volume of 100 μL and ambient column temperature. This method was capable to detect both the drug components of Amlodipine and Valsartan in presence of their degradation products (Amlodipine Imp-A and Valsartan Impurity-B) with the detection level of 0.05%. Amlodipine/Valsartan and their combination drug product were exposed to thermal studies, photolytic, hydrolytic and oxidative stress conditions, and samples analysed. Peak homogeneity data of Amlodipine and Valsartan is obtained using PDA detector, demonstrating the specificity. The method shows excellent linearity over range of 0.05–2.0% for Amlodipine; Amlodipine Impurity-A and 0.05–1.0% for Valsartan and Valsartan Impurity-B. The correlation coefficient for Amlodipine and Valsartan are 0.9999. The proposed method was found to be suitable and accurate for quantitative determination and the stability study of Amlodipine and Valsartan in pharmaceutical preparations.