[Experimental data on methicillin tolerance and penetration into the eye media]

Abstract

Tolerance of methicillin by the eye tissues was studied on its administration subconjunctively, into the front chamber and vitreous body of 20 rabbits. The studies showed that subconjunctival administration of the antibiotic was well tolerated in a dose of 50 mg, and its administration into the front chamber and vitreous body was well tolerated in doses of 1.0-2.5 mg. Penetration of methicillin into the fluids of the front chamber and vitreous body on its instillation into the conjunctive sac in a form of 2.5 per cent solution, its subconjunctival and retrobulbar injection in a dose of 50 mg and intramuscular administration in a dose of 40 mg/kg was studied. Animals with aseptic inflammation of the eyes due to burns of the cornea with 1 N hydrochloric acid were taken into the experiments. The method of agar diffusion with Staph. aureus 209P as the test-microbe was used. The studies showed that the highest methicillin concentrations in the eye media were observed an hour after the antibiotic subconjunctival administration. In the vitreous body they were 16 times lower than those in the front chamber fluid. The retrobulbar injections had no advantages over the subconjunctival administration for the antibiotic maximum concentrations in the vitreous body. The concentration of methicillin in the front chamber fluid on its local administration was many times higher than the minimum inhibitory concentration for staphylococci and may be considered as a therapeutic one.