US Patent 4,866,083
United States Patent and Trademark Office
University of Iowa Research Foundation (Iowa City, IA, US)
An oxazolidine derivative of phenylephrine, and the non-toxic pharmaceutically acceptable salt forms thereof. The prodrug is much quicker absorbed across the cornea of the eye, does not induce the same unwanted side effects as phenylephrine, and can produce the same mydriatic effect as phenylephrine at dosage levels of approximately one-tenth the level of phenylephrine.
Schoenwald, Ronald D. and Chien, Du-shieng 2-t-butyl-3 alkyl-5-(m-hydroxyphenyl)-1,3-oxazolidines having mydriatic effect. US Patent 4,866,083 filed November 06, 1987 and issued September 12, 1989. https://ir.uiowa.edu/patents/68