Penetration of amikacin into aqueous humor of rabbits

Amikacin is an aminoglycoside antibiotic that has poor corneal penetration due to its hydrophilic properties. The purpose of this study was to compare and evaluate the penetration of amikacin sulfate into aqueous humor of the rabbit eye when applied by different routes and concentrations, namely 100 or 250 mg/ml topical fortified amikacin eye drops, 100 or 250 mg/ml amikac in-embedded soft contact lenses and 25 mg subconjunctival amikacin injectio n. One hour after application, amikacin was not detectable in any of the 10 0 mg/ml concentration groups. High levels of amikacin above the minimum inh ibitory concentration for susceptible bacteria were detected when applied s ubconjunctivally and by 250 mg/ mi topical fortified routes. Topical fortif ied amikacin 250 mg/ml reached the highest value in the aqueous (p < 0.05). Our results point out the poor corneal penetration of amikacin in standard concentrations from the intact rabbit cornea and that subconjunctival inje ctions might provide satisfactory penetration. Copyright (C) 2001 S. Karger AG, Basel.