Pharmaceutical composition containing a stable modification of torasemide
AssigneeBoehringer Mannheim GmbH
InventorsFritz Topfmeier, Gustav Lettenbauer
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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.
Claims4
A diuretic pharmaceutical composition comprising an effective amount of rapidly dissolving stable crystalline torasemide of pure modification I (monoclinic, space group P2.sub.1 /c, melting point .Badd.[169.degree. C.].Baddend. of about 159.degree. C. to about 161.5.degree. C., in prism form ) substantially free of crystalline torasemide of modification II (monoclinic, space group P2/n, melting point .Badd.[162.degree. C.].Baddend. of about 157.5.degree. C. to about 160.degree. C., in leaflet form ) and a pharmacologically acceptable carrier, said torasemide of modification I being storage stable in tablet form and 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.
A method of producing a diuretic effect in a patient, said method comprising orally administering to the patient at least one storage-stable table consisting essentially of torasemide of pure modification I (monoclinic, space group P2.sub.1 /c, melting point of about 159.degree. to about 161.5.degree. C., in prism form) and being substantially free of crystalline torasemide of modification II (monoclinic, space group P2/n, melting point of about 157.5.degree. C. to about 160.degree. C., in leaflet form).
Dependencies are inferred from the claim text.