A precise & accurate stability-indicating analytical method was developed & validated for the estimation of related substances and degradants of allopurinol tablets. Stressed Conditions like exposure to acidic media (5N HCl), basic media (5N NaOH), oxidative media (10% H202), and photolytic degradation (254 nm) at room temperature and thermal degradation of tablets at 80ºC were conducted in order to develop a rapid and sensitive stability indicating Reverse Phase High Performance Liquid Chromatography (RP- HPLC) method. Allopurinol tablets showed significant degradation under all stress conditions and no peak observed at the retention time of allopurinol in the forced degradation study and degradation was under ICH limits. The method was linear in the range of 0.051â0.760 ?g/mL (10%-150%) allopurinol concentrations. Accuracy was determined by spiking allopurinol tablet solution with known impurities. Excellent recoveries of Impurities A, B, C (96 â 98.18 %) proved that the method was sufficiently accurate. The Limit of Detection (LOD) and Limit of Quantitation (LOQ) of allopurinol were found to be 0.02?g/mL and 0.05?g/mL respectively. The LOD and LOQ of Impurity A, Impurity B and Impurity C were also determined. It was concluded that the developed method was precise and accurate for the determination of allopurinol and its degradants.
