Research Article
Degradation Pathway for Eplerenone by Validated Stability Indicating UP-LC Method
Figure 1
Chemical structures and names of eplerenone and its impurities. (a) Eplerenone: pregn-4-ene-7, 21-dicarboxylic acid, 9, 11-epoxy-17-hydroxy-3-oxo, γ-lactone, methyl ester (7α, 11α, 17α) (molecular weight 414.49), (b) impurity -1: (11a,17a)-11,17-dihydroxy-3-oxo-pregna-4,6-diene-21-carboxylic acid (molecular weight 356.46), (c) impurity-2 : 5′R(5′alpha),7′beta-20′-amino hexadecahydro-11′beta-hydroxy-10′a,13′alpha-dimethyl-3′,5′-dioxospiro[furan-2(3H),17′alpha(5′H)-methano[4H[cyclopenta[a]phenathrene]-5′-carbonitrile (molecular weight 410), (d) impurity-3 : 4′S(4′alpha),7′alpha-hexadecahydro-11′alpha-hydroxy-10′beta,13′beta-dimethyl-3′,5,20′-trioxospiro [furan-2(3H),17′beta-methanolcyclopenta[a]phenanthrene]-5′beta(2′H) carbonitrile (molecular weight 411), (e) impurity-4: Methyl hydrogen 11 alpha, 17alpha-dihydroxy-3-oxopregn-4-ene-7 alpha, 21- dicarboxylate, gamma-lactone (molecular weight 416), and (f) 0.31& 0.86 RRT degradation impurity: methyl hydrogen 9,11 dihydroxy,17-α-hydroxy-3-oxopregn 7-α-carbonate, 21-α-carboxylic acid. (molecular weight 451).
