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Mydriasis From Topically Administered Phenylephrine HCl Powder.
Published 1980 · Medicine
Microgram amounts of finely powdered phenylephrine HCl were administered to the conjunctiva of volunteers. A dose-response curve for white subjects showed a threshold mydriasis of less than 5 micrograms and a clinically useful mydriasis was obtained with one application of 50 micrograms. The time-response curve for the one time use of 50 micrograms of the powder was equivalent to giving three applications of 10% phenylephrine HCl drops. Twenty-five micrograms of pilocarpine HCl powder produced marked miosis. We investigated methods to deliver nonirritating microgram amounts of powdered phenylephrine HCl, pilocarpine HCl, and fluorescein.