Grepafloxacin Concentration in Ocular Tissues after Intravenous Infusion in Rabbits with Intraocular Inflammation

Purpose: To determine the penetration of grepafloxacin into ocular tissues during experimental ocular inflammation. Methods: 10 albino and 10 pigmented rabbits underwent a continuous intravenous infusion of the drug 24 h after injecting Salmonella typhimurium toxin intravitreously, creating ocular inflammation. The animals were killed and grepafloxacin levels were determined in plasma and ocular tissues using high performance liquid chromatography. Results: Grepafloxacin levels achieved a steady-state plasma concentration of 1.5 µg/ml. The drug diffused more towards vascularized tissues (chorioretina and iris) in both albino and pigmented rabbits with a tissue/serum ratio higher than 1. Grepafloxacin showed more affinity to pigmented tissue, rising levels of 40,000–50,000 ng/g in the chorioretina and iris in pigmented animals. After inflammation, grepafloxacin intraocular penetration increased in albino animals with levels exceeding the minimum inhibitory concentration for the most common ocular pathogens. Conclusion: Grepafloxacin intraocular penetration is higher in pigmented tissues. Ocular inflammation increases the drug penetration into the vitreous.