Different iris coloration and uptake of a fluoroquinolone agent into the iris ciliary body of rabbit eyes.

In order to know the correlation of a drug with high affinity to melanin in the iris ciliary body with the amount of melanin contained in the iris ciliary tissues, an in vivo study was performed on pigmented rabbits with brown or blue irises and albino rabbits. The melanin concentrations in the iris ciliary bodies of pigmented rabbits with brown and blue irises and nonpigmented rabbit eyes with whitish irises were determined. The mean concentrations of melanin in the eyes with brown-, blue- and whitish-colored irises were 47.43, 34.73 and below 0.2 microgram/mg tissue, respectively. The amount of sparfloxacin uptake in the iris ciliary bodies of eyes with brown, blue and whitish irises administered as 40 microliters of 0.3% solution 5 times every 5 min was 15.46 +/- 2.07, 8.53 +/- 1.87 and 1.9 micrograms/g, respectively. The results may be useful for intraocular drug dynamics studies.