Синонимы: 4-Ethoxy-3-(1-methyl-7-oxo-3-propyl-6,7-dihydro-1Hpyrazolo[4,3-d]pyrimidin-5-yl)benzenesulfonic Acid, Sildenafil Citrate Imp. D (Pharmeuropa), 3-(4,7-Dihydro-1-methyl-7-oxo-3-propyl-1H-pyrazolo[4,3-d]pyrimidin-5-yl)-4-ethoxybenzenesulfonic Acid, Sildenafil Citrate Impurity D, Sildenafil Impurity D