Determination of Inherent Stability of Valsartan by Stress Degradation and Its Validation by HPLC

Abstract

The objective of the present study was to develop a validated stability-indicating assay method (SIAM) for valsartan subjecting it to forced decomposition under hydrolysis, oxidation, photolysis, thermal and accelerated stress conditions. Separation of drug from major and minor degradation products was successfully achieved by High Performance Liquid Chromatography (HPLC) on Kromasil C18 column utilizing, water: acetonitrile in the ratio of 60:40 with 0.5 % of ortho phosphoric acid (OPA). The detection was carried out in the range of 190-400 nm. The same major decomposition product could be seen in all the decomposed solutions. The method was validated with respect to linearity, precision (including intermediate precision), accuracy and specificity. The response was linear in the drug concentration range of 20-320 N less than g/ml. The correlation coefficient was found 0.9996. The % RSD values for intra- and inter-day precision studies were 1 %. The recovery of the drug from a mixture of degraded samples was ranged between 98.76 to 100.9%. PDA peak purity test confirmed the specificity of the method. The method could also be successful in analysis of drug in marketed tablets subjected to stability testing under accelerated conditions of temperature, hydrolysis, humidity, and to thermal and photolytic stress.