Granted Patent
Utility
US 4,898,928 · App. 07/164,604
Polyacetal and polyketal hydrogels formed from acetals or ketals and polyols
Inventors:
Jorge Heller, Donald W. H. Penhale, Steve Y. Ng
Patented Case
View Patent ↗
Granted: Feb 6, 1990
Filed: Mar 7, 1988
Inventors
Jorge Heller
Donald W. H. Penhale
Steve Y. Ng
Assignee (at issue)
Sandoz Pharmaceuticals 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.