Patents by Inventor Leif G. Ahrgren

Leif G. Ahrgren 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).

  • Method for preparation of sulfated polysaccharides by treating the polysaccharide with a reducing agent before sulfation
    Patent number: 4814437
    Abstract: A new method for preparation of sulfated polysaccharides by means of pyridine-chlorosulfonic acid reagents. The polysaccharide is before sulfation treated with a reducing agent, e.g. sodium borohydride.
    Type: Grant
    Filed: February 25, 1988
    Date of Patent: March 21, 1989
    Assignee: Pharmacia AB
    Inventors: Anthony N. de Belder, Leif G. Ahrgren, Tomas Malson
  • Shaped article and processes for its preparation
    Patent number: 4772419
    Abstract: A shaped article based upon cross-linked, possibly derivatized hyaluronic acid or a salt thereof is characterized in that it has a dry matter content of at least 65 percent by weight and a tensile strength of at least 2 N/cm.sup.2. The shaped article may be prepared by pressure-drying or freeze-drying a corresponding hyaluronic acid gel.
    Type: Grant
    Filed: February 21, 1986
    Date of Patent: September 20, 1988
    Assignee: Pharmacia AB
    Inventors: Tomas Malson, Leif G. Ahrgren, Anthony N. de Belder
  • Dextran or crosslinked dextran having quaternary amino groups
    Patent number: 4591638
    Abstract: The invention relates to a new polymer containing quarternary amino group based on dextran or cross-linked dextran. The quarternary amino groups are of the formula ##STR1## where R.sub.1, R.sub.2 and R.sub.3, which may be identical or different, are lower alkyl groups of 1-5 carbon atoms or lower hydroxyalkyl groups of 2-5 carbon atoms and 1-2 hydroxy groups. At most one atom other than carbon and hydrogen is bound to the same carbon atom in the hydroxy alkyl group.
    Type: Grant
    Filed: May 11, 1982
    Date of Patent: May 27, 1986
    Assignee: Pharmacia AB
    Inventors: Leif G. Ahrgren, Anthony N. de Belder