Designing of Force Degradative Studies and Development of Validated Stability Indicating UV Spectrophotometric Assay Method for the Estimation of Isosorbide Dinitrate in Tablet Dosage Form

Isosorbide Dinitrate (ISD) is a moderate to long acting oral organic nitrate which acts as a vasodilator profoundly used in the treatment of angina pectoris, a condition which occurs when the oxygen supply to the myocardium is insufficient for its needs. It is slightly soluble in water and propanol, sparingly soluble in ethanol and freely soluble in methanol. The most economical solvent Distilled water was choosen as a solvent. The drug has absorption maximum (method A) at 304nm, Area under curve (method B) at 300-310 and first order derivative method (method C) at 287nm. Linearity for all three methods was found in the range of 5-25 μg/ml with Correlation coefficient is 0.999, Standard error is 0.001. The drug sample was analyzed by UV spectroscopy using distilled water as solvent and the average content of drug present in the formulation was found to be 99.7%. The % recovery of accuracy studies was found to be 99.1 % for method A, 101.5 % for method B, 100.6 % for method C. The %RSD of precision was found to be 1.11% for intraday, 1.22 % for inter day. The force degradation studies of Isosorbide Dinitrate was done on Stress degradation by hydrolysis under alkaline condition by using 0.1N NaOH was found to be 10.09% for 24hrs, 13.3% for 3days, 14.2% for 5days .Stress degradation by hydrolysis under acidic condition by using 0.1N HCl and degradation was found to be  2.68% for 24hrs, 9.7% for 3days, 11.9% for 5days.  Oxidative degradation was done by using hydrogen peroxide (3%v/v) and degradation was found to be 3.22% for 24hrs, 5.06% for 3days, and 8.29% for 5days. The proposed methods can be successfully employed for quality control during manufacture and for assessment of the stability of Isosorbide Dinitrate in bulk samples and its tablet dosage forms.