Roxithromycin EP Impurity D Roxithromycin Impurity 4(Roxithromycin EP Impurity D) (9Z)-9-[O-[(2-Methoxyethoxy)methyl]oxime] Erythromycin Roxithromycin EP Impurity D/(3R,4S,5S,6R,7R,9R,11S,12R,13S,14R,Z)-6-(((2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyltetrahydro-2H-pyran-2-yl)oxy)-14-ethyl-7,12,13-trihydroxy-4-(((2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyltetrahydro-2H-pyran-2-yl)ox Roxithromycin Impurity D Erythromycin, 9-[O-[(2-methoxyethoxy)methyl]oxime], (9Z)- Roxithromycin EP Impurity D ((Z)-Roxithromycin/ Erythromycin 9-(Z)-[O-[(2-Methoxyethoxy)methyl]-oxime]) Erythromycin 9-(Z)-[O-[(2-methoxyethoxy)methyl]oxime]