|Title:||Pharmaceutical composition containing a stable modification of torasemide|
|Abstract:||The present invention provides a process for the preparation of cystalline torasemide in the pure modification I (monoclinic, space group P2.sub.1 /c, melting point 162.degree. C.) from torasemide of modification II (monoclinic, space group P2/n, melting point 169.degree. C.), wherein a suspension of torasemide of modification II is stirred in water with the addition of a catalytic amount of modification I until the rearrangement is complete. The present invention also provides pharmaceutical compositions containing torasemide of modification I.|
|Inventor(s):||Topfmeier; Fritz (Heidelberg, DE), Lettenbauer; Gustav (Lampertheim, DE)|
|Assignee:||Boehringer Mannheim GmbH (Mannheim, DE)|
1. A diuretic pharmaceutical composition comprising an effective amount of rapidly dissolving crystalline torasemide of pure modification I (monoclinic, space group P2.sub.1
/c, melting point 169.degree. C.) substantially free of crystalline torasemide of modification II (monoclinic, space group P2/n, melting point 162.degree. C.) and a pharmacologically acceptable carrier, said torasemide of modification I having
solubility characteristics such that at least 60% is dissolved in water after 15 minutes, and at least 80% is dissolved in water after 30 minutes.
2. The composition of claim 1 comprising, by weight, approximately:
100 parts of the torasemide of modification I and, as the carrier,
20 parts lactose monohydrate,
77 parts maize starch,
2 parts silicon dioxide and,
1 part magnesium stearate.
3. The composition of claim 1 comprising, by weight, approximately:
25 parts of the torasemide of modification I and, as the carrier,
605 parts lactose monohydrate,
160 parts maize starch,
6 parts silicon dioxide and
4 parts magnesium stearate.