FORMATION OF ADRENALINE IN THE IRIS CILIARY BODY FROM ADRENALONE DIESTERS

Many diesters of aldrenalone have high ocular sympathomimetic activity although adrenalone itself, even if delivered intraocularly, is practically inactive. These diesters cannot be considered prodrugs of adrenalone, since adrenalone is not a drug. The mechanism of action of these adrenalone derivatives was studied on the selected, potent diisovaleryl adrenalone. Adrenaline [epinephrine] was formed from the diester, but not from adrenalone. While the inactive adrenalone was formed hydrolytically and found in every compartment of the eye, the active epinephrine (adrenaline) was found only in the iris-ciliary body, as a result of a reduction-hydrolytic steps sequence. The adrenalone diesters represent a type of site-specific delivery system for epinephrine.