| abstract |
The 1-(2-methoxyethyl)-2-methyl-4,9-dioxo-3-(pyrazin-2-ylmethyl)-4,9-dihydro-1H-naphtho[2,3-d]imidazol-3-ium bromide of the invention and its crystals, particularly .alpha. -and .beta.-form Crystals, have no hygroscopic property, have excellent stability and therefore are useful as production materials of medicines. Particularly, the .beta.-form Crystal is most stable and markedly useful as a bulk for medicines. |