Abstract
The effects of habekacin on corneal ulceration, caused by Pseudonnonas aeruginosa IFO 3455, were studied in mice, in comparison with gentamicin and tobramycin. The minimal inhibitory concentrations of the antibiotics for the organism were: habekacin 2 μg/ml, genta-micin 2μg/ml, and tobramycin 1 μg/ml. Habekacin showed protective and therapeutic effects on Pseudomonas keratitis. The 50% effective dose was approximately 1 μg per mouse, when the drug was topically applied three hours after the infection, and about 0.2 mg per mouse, when the antibiotic was intramuscularly injected one hour after the bacteria] chall enge to the cornea. Significant therapeutic and protective activities of habekacin were observed even by starting the topical and/or intramuscular treatment after the corneal ulcers were formed: i.e. 15 hours after the bacterial infection. Complete cure of Pseudonzonas keratitis was found within a week in a number of the infected mice by both topical and systemic administrations of the drug. The protective and therapeutic effects of habekacin were comparable to those of gentamicin and tobramycin.