Granted Patent
Utility
US 4,680,312 · App. 06/674,357
Stable prostaglandin E gels utilizing colloidal silicon dioxide as a gel-forming agent
Inventor:
Brian Scott Johnson
Patented Case
View Patent ↗
Granted: Jul 14, 1987
Filed: Nov 21, 1984
Inventor
Brian Scott Johnson
Assignee (at issue)
The Upjohn Co.
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.