Abstract
Abstract: :
Purpose: Mycophenolate mofetil (MMF), the morpholinoethylester of mycophenolic acid (MPA), is an immunomodulatory agent, whose benefit for prophylaxis of corneal transplantation rejection and treatment of immuno-mediated ocular diseases has been revealed recently. Due to possible side effects of systemic application topical application would be helpful. Aim of this study was to evaluate pharmacokinetics of topical applied MMF and MPA in different galenic preparations in a rabbit model. Methods: Animals were treated in 4 different groups . A loading dose of 5 x 50 µl MMF preparation (MMF-cyclodextrin-complex [MMF-CD], MMF suspension [MMF-S], MPA) were instilled in the right eye of each animal (4 in each group). Eyes were enucleated after 30 min 60 min and 240 min and MMF and MPA concentrations were measured in conjunctiva (CJ), cornea (CR), aqueous humor (AH), iris/ciliary body (IC), vitreous(V) and sclera (SC). Moreover serum drug concentrations were determined. Results: No ocular irritation was observed when MMF-CD was applied, whereas MMF-S caused little conjunctival hyperemia. After application of MMF-CD, only the active drug MPA could be detected in all tissues. In AH 50 µg/ml MPA could be detected after 60 min. MPA concentrations in AH CR, SC and CJ after 60 min. (60x10-6 µg/µg in CR) were significantly higher with MMF-CD compared to MMF-S. After application of MMF-S only MPA was detectable in CR and AH whereas MMF and MPA could be found in CJ, SC and IC. Conclusion: MMF-CD eye drop formulation obtain higher intraocular concentrations of active drug than MMF-S causing less irritaion. CD`s are suitable tools to improve ocular availability of hydrophobic drugs like MMF. A topical therapy of MMF could be possible.
Keywords: 435 immunomodulation/immunoregulation • 514 pharmacology • 607 transplantation