CRYSTAL OF 6- [4-(4'-PYRIDYL)AMINOPHENYL] -4, 5-DIHYDRO-3(2H)-PYRIDAZINONE HYDROCHLORIDE TRIHYDRATE

摘要

The present invention provides crystals of 6-Ä4-(4-pyridylamino)phenylÜ-4,5-dihydro-3(2H)-pyridazinone hydrochloride trihydrate useful as a medicament for therapeutic treatment of cardiac failure, and the like; and a pharmaceutical composition comprising said crystals as an active ingredient. <??>The crystal of the present invention has characteristic absorption peaks (2 &thetas; degrees) at 12.9 (+/-0.2 DEG ) and 19.0 (+/-0.2 DEG ), for example, in powder X-ray diffractometry.