A new rapid Stability indicating RP-PDA-UPLC method for the estimation of Assay of Pemetrexed disodium-An anti-Lung cancer drug from lyophilized parenteral formulation

A new rapid stability-indicating reversed phase ultra-performance liquid chromatographic (RP-UPLC) method with a linear gradient and shortest run time of 4.0 minutes is developed for the determination of assay of pemetrexed disodium, an anti-cancer drug from its lyophilized parenteral formulation. The method is developed on Waters binary UPLC, equipped with Aquity BEH C18 column and system set with mobile phase A as 0.1% ortho-phosphoric acid and B as Acetonitrile. The drug product is exposed to forced stress conditions like peroxide, acid, base, hydrolytic, thermal, and photolytic degradation, within which major degradants were observed in acid stress at 1N HCl 60°C and 3% peroxide stress at room temperature. Pemetrexed (main peak) and its degradant peaks were well separated and were monitored at UV-230nm. Evaluation of spectral purity for main component is performed using PDA (photo diode array) in presence of its degradants formed during stress studies, which assures the stability indicating capability of the method. % RSD for mean of precision and accuracy at 3 different levels ranging from 50 to 150% were within limits and coefficient of correlation found > 0.999 for linearity. The newly developed UPLC assay method is fully validated and found to be specific, Robust, Precise, Linear and Accurate in determining assay of Pemetrexed from drug product as per ICH guidelines.