Table of Contents
ISRN Pharmaceutics
Volume 2012 (2012), Article ID 251247, 8 pages
http://dx.doi.org/10.5402/2012/251247
Research Article

Degradation Pathway for Eplerenone by Validated Stability Indicating UP-LC Method

1Department of Chemistry, Sri Krishnadevaraya University, Anantapur 515003, Andhra Pradesh 515003, India
2Hetero Labs Ltd., Hetero House, Sanathnagar, 500078 Andhra Pradesh, Hyderabad, India
3InvaGen Pharmaceuticals Inc., Hauppauge 11749, NY, USA

Received 12 March 2012; Accepted 31 May 2012

Academic Editors: M. Nasr and C. J. Salomon

Copyright © 2012 Kondru Sudhakar Babu 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.

Abstract

Degradation pathway for eplerenone is established as per ICH recommendations by validated and stability-indicating reverse phase liquid chromatographic method. Eplerenone is subjected to stress conditions of acid, base, oxidation, and thermal and photolysis. Significant degradation is observed in acid and base stress conditions. Four impurities are studied and the major degradant (RRT about 0.31) was identified by LC-MS and spectral analysis. The stress samples are assayed against a qualified reference standard and the mass balance is found close to 99.5%. Efficient chromatographic separation is achieved on a Waters symmetry C18 stationary phase with simple mobile phase combination delivered in gradient mode and quantification is carried at 240 nm at a flow rate of 1.0 mL min−1. In the developed LC method the resolution between eplerenone and four potential impurities (imp-1, imp-2, imp-3, and imp-4) is found to be greater than 4.0. Regression analysis shows an value (correlation coefficient) of greater than 0.999 for eplerenone and four potential impurities. This method is capable to detect the impurities of eplerenone at a level of 0.020% with respect to test concentration of 1.0 mg mL−1 for a 20 μL injection volume. The developed UPLC method is validated with respect to specificity, linearity and range, accuracy, precision, and robustness for impurities and assay determination.