Identification of Four New Degradation Products of Epirubicin Through Forced Degradation, LC–UV, MS n and LC–MS–TOF Studies

• Published in: Journal of chromatographic science 2015-11, Vol.53 (10), p.1737-1748
• Main Authors: Kaushik, Dheeraj, Saini, Balraj, Bansal, Gulshan
• Format: Article
• Language: English
• ISSN: 0021-9665; 1945-239X
• DOI: 10.1093/chromsci/bmv083

Epirubicin (EPI) was subjected to International Conference on Harmonization recommended forced degradation under the conditions of hydrolysis, oxidation, dry heat and photolysis to characterize its possible impurities and/or degradation products. The drug was found highly unstable to alkaline hydrolysis even at room temperature, unstable to acid hydrolysis at 80°C and to oxidation at room temperature. The hydrolytic and oxidative degradation products were resolved on an Agilent RP8 (150 mm × 4.6 mm; 5 µm) column with isocratic elution using mobile phase composed of ammonium formate (10 mM, pH 3.0), acetonitrile and methanol. The drug degraded to four oxidative products (O-I, O-II, O-III and O-IV) and to one acid hydrolyzed product (A-I). Purity of each peak in liquid chromatography–ultraviolet (LC–UV) chromatogram was ascertained through photodiode array (LC–PDA) analysis. The products were characterized through electrospray ionization–mass spectrometry (+ESI–MS n ) studies on EPI and liquid chromatography–time of flight mass spectrometry (LC–MS–TOF) studies on degraded drug solutions. The products, O-I–O-IV, were characterized as 2-hydroxy-8-desacetylepirubicin-8-hydroperoxide, 4-hydroxy-8-desacetylepirubicin-8-hydroperoxide, 8-desacetylepirubicin-8-hydroperoxide and 8-desacetylepirubicin, respectively, and product A-I was characterized as deglucosaminylepirubicin. While A-I was found to be a pharmacopoeial impurity, all oxidative products were found to be new degradation impurities. The mechanisms and pathways of degradation of EPI were discussed and outlined.