OCULAR ABSORPTION AND METABOLISM OF TOPICALLY APPLIED EPINEPHRINE AND A DIPIVALYL ESTER OF EPINEPHRINE

  • 1 January 1978
    • journal article
    • research article
    • Vol. 17  (4) , 315-321
Abstract
An analog of epinephrine (EPI), dipivalyl epinephrine (DPE), reduced intraocular pressure (IOP) significantly at lower concentrations than EPI itself. To understand the reason for this increased activity, the ocular penetration, distribution and metabolism of these 2 compounds were compared. About 10 times as much DPE as EPI was absorbed by rabbit eyes, with the cornea as the major repository for the increased amount of drug absorbed. Comparison of the partition coefficients of the 2 compounds showed DEP to be from 100-600 times as lipophilic as EPI. The radioactive materials found in the aqueous humor after treatment with either compound had the same mobility in a TLC system. Following the increased penetration of the lipophilic prodrug, DPE is hydrolyzed to EPI in the eye.