Granted Patent
Utility
US 4,414,399 · App. 06/485,313
5/6 Carboxyphthalides
Inventors:
Paul Schmidt, William M. Hung
Patented Case
View Patent ↗
Granted: Nov 8, 1983
Filed: Apr 15, 1983
Inventors
Paul Schmidt
William M. Hung
Assignee (at issue)
Sterling Drug, Inc.
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.