Intraocular dynamic mode differences of new quinolone antibacterial agents between pigmented and albino rabbit eyes

The influence of melanin on the intraocular dynamics of a new quinolone anti-bacterial agent, NY-198, was investigated in albino and pigmented rabbit eyes. Drug uptake into the cornea of the removed eye was almost the same in both albino and pigmented eyes. However, drug uptake into the iris-ciliary body and release volume and time from the tissues were significantly higher and longer in pigmented eyes than in albino rabbit eyes. Penetration of NY-198 into the cornea, the iris-ciliary body and the serum, administered either systemically or locally into the living eyes of pigmented rabbit was significantly higher than that observed in albino rabbit eyes. Drug affinity for melanin was examined utilizing synthetic melanin. Regarding OFLX, NY-198, CEZ, LMOX, CMX, SISO and TOB, drug-melanin combined ratios ranged from 9.1% to 95.5%. SISO and TOB showed antibacterial activity reduction against E, Coli and B. Subtilis. The results suggest that melanin influences the intraocular dynamic mode of a new quinolone agent, NY-198, and that useful information about the influence of melanin in the drug dynamics of ocular tissues can be obtained from in vitro experiments.