Ocular pharmacokinetics of latamoxef and cefaclor in humans. Penetration into aqueous humor.

Penetrations of latamoxef (LMOX) and cefaclor (CCL) into the aqueous humor after intravenous or oral administration were investigated in patients admitted with cataract. Concentrations of antibiotics in plasma and aqueous humor were determined periodically by microbiological assay. LMOX disappeared from plasma in a monoexponential manner with a half-life of 2.7 h after intravenous administration at a dose of 1000 mg. The maximum concentration of LMOX in aqueous humor (4.7 micrograms/ml) was observed 2 h after administration. When CCL was administered orally at a dose of 500 mg, the maximum concentration of CCL in aqueous humor was 0.53 microgram/ml 2 h after administration, whereas the maximum plasma concentration of 8.4 micrograms/ml was observed at 1 h. Pharmacokinetic analysis (simultaneous simulation) of plasma and aqueous humor concentration-time courses was done by using the best-fitting compartment model examined (modified two-compartment model). Prediction of the concentration of antibiotics in aqueous humor from the plasma concentration profile was also examined using the same compartment model in a separate experiment. The predicted concentration in aqueous humor was proved to fit reasonably with the measured concentration.