Patents Represented by Attorney, Agent or Law Firm Stuart L. Watt
  • Patent number: 5661125
    Abstract: The invention is to stable compositions of erythropoietin that contain an antimicrobial preservative thereby providing a multi-dose formulation. Preservatives useful in the pharmaceutical compositions of the present invention include benzyl alcohol, parabens, phenol and mixtures thereof. Other additives, including buffers may be included in the composition.
    Type: Grant
    Filed: May 24, 1995
    Date of Patent: August 26, 1997
    Assignee: AMGEN, Inc.
    Inventor: Thomas Wayne Strickland
  • Patent number: 5459031
    Abstract: The invention relates to the effects of certain cell culture and/or production parameters on the carbohydrate composition of a cell culture-derived recombinant glycoprotein. The methods of the invention demonstrate a practical method for controlling levels of a sialic acid derivative, NGNA, in secreted recombinant glycoproteins which will be useful in a variety of bioprocessing systems.
    Type: Grant
    Filed: June 17, 1994
    Date of Patent: October 17, 1995
    Assignee: Amgen Inc.
    Inventors: Tracy K. Blumen, Gustavo E. Grampp, David J. Hettwer
  • Patent number: 4927797
    Abstract: The present invention provides a catalyst system that exhibits unprecedented catalyst efficiencies and control of desired properties in the polymer product. The catalyst system includes a Toho-type, new generation titanium catalyst in combination with an electron donor described by the formula: ##STR1## wherein R.sub.1 is a bulky, basic alkyl or cycloalkyl group containing at least one secondary or tertiary carbon atom; R.sub.2 and R.sub.3 are alkyl or aryl groups; and R.sub.4 is an alkyl group with a primary carbon atom attached to the silicon atom. The system has a catalyst efficiency of at least about 30 kg/g-cat.2h as the Al/Si mole ratio varies from 20-200 in the system. The system easily achieves efficiencies over 60 kg/g-cat.2h. The system also exhibits good control over the xylene solubles, melt flow and molecular weight distribution of the polymer product.
    Type: Grant
    Filed: December 2, 1988
    Date of Patent: May 22, 1990
    Assignee: Fina Technology, Inc.
    Inventor: John A. Ewen
  • Patent number: 4892851
    Abstract: The invention provides a metallocene catalyst for use in preparing syndiotactic polyolefins. The catalyst comprises a bridged metallocene in which one of the cyclopentadienyl rings is substituted in a substantially different manner from the other ring. It was discovered that this type of catalyst is highly syndiospecific, and it also produces a polymer with a novel microstructure. The invention further includes the use of one or more of the catalysts in a polymerization process. The catalyst is generally described by the formulaR"(CpR.sub.n)(CpR'.sub.m)MeQ.sub.kwherein each Cp is a cyclopentadienyl or substituted cyclopentadienyl ring; each R.sub.n and R'.sub.m is the same or different and is a hydrocarbyl radicals having 1-20 carbon atoms; R" is a structural bridge between the two Cp rings imparting stereoigidity to the catalyst; Me is a group 4b, 5b, or 6b metal from the Periodic Table of Elements; each Q is a hydrocarbyl radical having 1-20 carbon atoms or is a halogen; 0.ltoreq.k.ltoreq.3; 0.ltoreq.n.
    Type: Grant
    Filed: July 15, 1988
    Date of Patent: January 9, 1990
    Assignee: Fina Technology, Inc.
    Inventors: John A. Ewen, Abbas Razavi
  • Patent number: 4794096
    Abstract: The present invention provides a catalyst system for the polymerization and copolymerization of olefins with the system comprising a chiral, stereorigid hafnium metallocene catalyst in combination with an aluminum compound. The aluminum compound is preferably an alumoxane and may be a mixture of alumoxane and trimethyl aluminum. It was discovered that this mixture causes a transformation of the catalyst over time. The catalyst system may also include a solvent to increase the solubility of the metallocene catalyst. It was discovered that these catalyst systems produce useful polymer products with molecular weights greater than 10,000.
    Type: Grant
    Filed: September 11, 1987
    Date of Patent: December 27, 1988
    Assignee: Fina Technology, Inc.
    Inventor: John A. Ewen