Penetration of intravenous moxalactam into human aqueous humor

Intraocular penetration of moxalactam disodium, a new broad-spectrum oxa-beta-lactam antibiotic, was studied in 18 patients undergoing cataract surgery. The antibiotic was administered in a 2-g single dose by intravenous drip during a 20-minute period. After 40 to 230 minutes, moxalactam aqueous humor concentrations ranged from 1.1 to 5.0 micrograms/mL (mean, 2.3 micrograms/mL). The ratio of aqueous humor concentrations to concomitant serum concentrations ranged from 1.6% to 9.8%. The achievable aqueous moxalactam concentrations were well above the minimum inhibitory concentrations of most Gram-negative enteric bacilli but not of Pseudomonas and staphylococci.