Patents by Inventor William Eldredge Perkins

William Eldredge Perkins 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).

  • Polymeric drug delivery system
    Patent number: 5827925
    Abstract: A drug delivery system adapted to release an effective amount of a drug at pH values of about 1 to 7 without releasing a significant amount of the drug at pH values of about 7 and above, the system comprising a polymeric material and a drug covalently bonded to the polymeric material through a pH sensitive covalent bond capable of being cleaved in the pH range of 1 to about 7.
    Type: Grant
    Filed: November 2, 1993
    Date of Patent: October 27, 1998
    Assignee: Monsanto Company
    Inventors: Samuel J. Tremont, Paul Waddell Collins, William Eldredge Perkins, Peter Hadley Jones