Topically Effective Acetazolamide Eye-drop Solution in Man

Abstract

Drug-cyclodextrin polymer co-complexes increase the solubility of lipophilic drugs in aqueous solutions, such as eye-drops, without affecting their lipophilicity. Also, the co-complexes are able enhance the ocular availability of the drug after topical administration. The anhydrase inhibitor acetazolamide was solubilized in an aqueous eye-drop formulation through formation of a co-complex with 2-hydroxypropyl-β-cyclodextrin and hydroxypropyl methylcellulose. The intraocular pressure (IOP)-lowering activity of a 1% (w/v) acetazolamide eye-drop solution was evaluated in nine ocular hypertensive patients. The patients were given the eye-drops three times a day for 28 days. Maximum IOP lowering activity was observed at 9 a m, 2 h after installation of the drops, with a mean IOP-lowering of 15.6 ± 8.9%. Through HP-β-CD-HPMC co-complex formation, it was possible to obtain a topically active aqueous acetazolamide eye-drop solution. In man, the 1% (w/v) acetazolamide eye-drop solution had less IOP-lowering activity than an aqueous 2% (w/v) dorzolamide eye-drop solution.