[In vitro topically applied fluoroquinolone penetration into the anterior chamber]

The penetration mode of five fluoroquinolone ophthalmic solutions (OFLX, NFLX, LVFX, LFLX and CPFX) through the rabbit cornea was examined with an in vitro experimental system. The system was an artificial anterior eye segment model made of acrylamide covered with a New Zealand albino rabbit cornea with a scleral flap. In vivo studies on the penetration of OFLX and NFLX ophthalmic solutions into the anterior chamber of albino rabbits were performed separately. Parameters gained from in vivo pharmacokinetic analysis and those from the model eye were compared. The permeability coefficients (K) (cm/s) through the cornea and partition coefficient were 6.95 x 10(-7) cm/s in LVFX, 6.78 x 10(-7) cm/s in OFLX, 3.58 x 10(-7) cm/s in LFLX, 2.46 x 10(-7) cm/s in CPFX and 0.06 x 10(-7) cm/s in NFLX, and 0.24, 0.23, 0.14, 0.06 and 0.07, respectively. High correlation was seen between the corneal permeability coefficients, and the partition coefficient Cmax of OFLX obtained from the in vivo study was higher than that of NFLX. The applied experimental system would be a useful tool for the estimation of the in vivo Cmax of the examined drug.