US Patent 4,623,664
United States Patent and Trademark Office
University of Iowa Research Foundation (Iowa City, IA, US)
An oil suspension, preferably sesame seed oil suspension, of the base form of phenylephrine as an opthalmic medicament. Surprisingly, the base form of phenylephrine is much quicker absorbed into the eye than the conventional acid salt form. As a result, lower dosage levels can be used to achieve the same mydriatic effect, thus reducing the risk of adverse side effects from systemic absorption.
Schoenwald, Ronald D. and Chien, Du-shieng Oil suspended phenylephrine. US Patent 4,623,664 filed October 31, 1985 and issued November 18, 1986. https://ir.uiowa.edu/patents/45