Specific analogs of ethoxzolamide will be synthesized and evaluated. These analogs are designed for the purpose of promoting penetration and distribution into the eye from a topically applied dose. From previous results and based upon a mathematical model, four additional 6-substituted analogs of ethoxzolamide will be synthesized: methylamino, acetamino, methoxymethyl and carboxyethyl. These are classical inhibitors designed for optimal corneal transport. In addition to optimal transport, a 6-amino analog of ethoxzolamide has been found to be five-fold more potent than ethxzolamide. Lipophilic substitution will optimize its transport. Furthermore, N-alkyl and/or N-hydroxyl sulfonamides have been identified which are potent """"""""nonclassical"""""""" inhibitors of carbonic anhydrase. Their potency will be optimized by systematically synthesizing various N-substituted sulfonamides. These results will provide information for the design, synthesis and evaluation of 6-substituted and N-substituted ethoxzolamide analogs. These analogs will represent both optimal corneal transport and optimal potency. The following information will be determined for most synthesized analogs; physical-chemical properties (partition coefficients, CAI, pKa and excised corneal permeability coefficients), pharmacological properties (duration of intraocular pressure, dose-response, and efficacy of repeated doses), pharmacokinetic properties (iris/ciliary body, aqueous humor, cornea and blood concentrations over time) and biochemical properties (type of carbonic anhydrase inhibition and Ki values). From this work a topical carbonic anhydrase inhibitor will be identified as a candidate for testing in glaucoma patients.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY003297-05
Application #
3257604
Study Section
(SSS)
Project Start
1981-06-01
Project End
1987-06-30
Budget Start
1985-07-01
Budget End
1986-06-30
Support Year
5
Fiscal Year
1985
Total Cost
Indirect Cost
Name
University of Iowa
Department
Type
Schools of Pharmacy
DUNS #
041294109
City
Iowa City
State
IA
Country
United States
Zip Code
52242
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Lewis, R A; Schoenwald, R D; Barfknecht, C F (1988) Aminozolamide suspension: the role of the vehicle in a topical carbonic anhydrase inhibitor. J Ocul Pharmacol 4:215-9
Putnam, M L; Schoenwald, R D; Duffel, M W et al. (1987) Ocular disposition of aminozolamide in the rabbit eye. Invest Ophthalmol Vis Sci 28:1373-82
Lewis, R A; Schoenwald, R D; Barfknecht, C F et al. (1986) Aminozolamide gel. A trial of a topical carbonic anhydrase inhibitor in ocular hypertension. Arch Ophthalmol 104:842-4
Duffel, M W; Ing, I S; Segarra, T M et al. (1986) N-Substituted sulfonamide carbonic anhydrase inhibitors with topical effects on intraocular pressure. J Med Chem 29:1488-94
Eller, M G; Schoenwald, R D; Dixson, J A et al. (1985) Topical carbonic anhydrase inhibitors. III: Optimization model for corneal penetration of ethoxzolamide analogues. J Pharm Sci 74:155-60
Eller, M G; Schoenwald, R D; Dixson, J A et al. (1985) Topical carbonic anhydrase inhibitors IV: Relationship between excised corneal permeability and pharmacokinetic factors. J Pharm Sci 74:525-9