DEVELOPMENT OF NOVEL STABILITY INDICATING HPLC METHOD AND CHARACTERIZATION OF OXIDATIVE DEGRADATION IMPURITY IN GRANISETRON DRUG SUBSTANCE

The objective of the present study is to identification of the oxidative degradation impurity in the Granisetron hydrochloride active ingredient and also the novel method developed based on the forced degradation studies performed on Granisetron Hydrochloride to well resolve the impurities from the API. Forced degradation studies were conducted as per ICH technical requirements prescribed stress conditions using acid, base, oxidative, thermal stress, and photolytic degradation to show the stability indicating power of the method. Significant degradation was observed during basic hydrolysis and in oxidative studies and no degradation was observed in other stress conditions. Characterization of oxidative degradation impurity was conceded with a combination of analytical and preparative LC isolation followed by LC-MS/MS, IR and ¹H and ¹³C NMR and 2D NMR spectral data. The HPLC chromatographic conditions were chosen to achieve satisfactory resolution between the impurities and API with shortest analysis time. Granisetron hydrochloride and its impurities were separated on Xbridge phenyl column (150mm×4.6 mm, 3.5 microns particle size). The mobile phase A composed of 10mM of Ammonium acetate in water (pH 8.5) and mobile phase B is Acetonitrile: Methanol (50:50, v/v) pumped at flow rate of 1mL/min with gradient. The column temperature was set at 40 °C and the detection wavelength at 305nm using UV detector. The developed HPLC method is suitable for LC–MS analysis which was further used to characterize the degradation products. Validation of the new developed HPLC-UV method was carried out in accordance with ICH guideline and met all required acceptance criteria.