US Patent 5,961,987
United States Patent and Trademark Office
University of Iowa Research Foundation (Iowa City, IA, US)
Tear production stimulants of reduced basicity prepared from cyclopropyl adducts of tertiary amines are disclosed.
Schoenwald, Ronald D. and Barfknecht, Charles F. Ocular protein stimulants. US Patent 5,961,987 filed October 31, 1996 and issued October 05, 1999. https://ir.uiowa.edu/patents/223