Patents by Inventor Gustav Lettenbauer

Gustav Lettenbauer has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Process for the enrichment and/or isolation of heart glycosides with the use of non-polar absorber resins
    Patent number: 5062959
    Abstract: Enrichment and purification of heart glycosides from mixtures of mother liquors is achieved by absorption on non-polar, large-pored resins from aqueous solution with possible addition of solvents miscible with water, and subsequent desorption with water/solvent mixtures or pure solvents.
    Type: Grant
    Filed: September 7, 1990
    Date of Patent: November 5, 1991
    Assignee: Boehringer Mannheim GmbH
    Inventors: Carl H. Ross, Rudolf Machat, Werner Haring, Gustav Lettenbauer
  • Pharmaceutical composition containing a stable modification of torasemide
    Patent number: 4822807
    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.
    Type: Grant
    Filed: October 20, 1987
    Date of Patent: April 18, 1989
    Assignee: Boehringer Mannheim GmbH
    Inventors: Fritz Topfmeier, Gustav Lettenbauer
  • Process for the preparation of a stable modification of torasemide
    Patent number: 4743693
    Abstract: The present invention provides a process for the preparation of crystalline 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 a pharmaceutical compositions containing torasemide of modification I.
    Type: Grant
    Filed: August 11, 1986
    Date of Patent: May 10, 1988
    Assignee: Boehringer Mannheim GmbH
    Inventors: Fritz Topfmeier, Gustav Lettenbauer
  • Process for the preparation of a stable modification of torasemide
    Patent number: RE34580
    Abstract: The present invention provides a process for the preparation of crystalline torasemide in the pure modification I (monoclinic, space group P2.sub.1 /c, .[.melting point 162.degree. C.).]. .Iadd.in prism form) .Iaddend.from torasemide of modification II (monoclinic, space group P2/n, .[.melting point 169.degree..),.]. .Iadd.in leaflet form), .Iaddend.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 a pharmaceutical compositions containing .Iadd.stable .Iaddend.torasemide of modification I.
    Type: Grant
    Filed: December 3, 1992
    Date of Patent: April 5, 1994
    Assignee: Boehringer Mannheim GmbH
    Inventors: Fritz Topfmeier, Gustav Lettenbauer
  • Pharmaceutical composition containing a stable modification of torasemide
    Patent number: RE34672
    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.
    Type: Grant
    Filed: April 8, 1993
    Date of Patent: July 26, 1994
    Assignee: Boehringer Mannheim GmbH
    Inventors: Fritz Topfmeier, Gustav Lettenbauer