Granted Patent
Utility
US 4,880,628 · App. 07/017,272
Sustained release composition
Inventors:
William Maxwell Allen, Jr., Bernard F. Sansom, Alan D. Wilson, Havard J. Prosser, David M. Groffman
Patented Case
View Patent ↗
Granted: Nov 14, 1989
Filed: Feb 20, 1987
Inventors
William Maxwell Allen, Jr.
Bernard F. Sansom
Alan D. Wilson
Havard J. Prosser
David M. Groffman
Assignee (at issue)
NATIONAL RESEARCH DEVELOPMENT CORPORATION
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.