Abstract
Purpose: :
To determine the distribution of the active pharmaceutical ingredient in XibromTM (bromfenac ophthalmic solution) in ocular tissues.
Methods: :
Fifty µl of 14C–bromfenac ophthalmic solution (20–25 µCi) was administered using a calibrated pipette into right eye of each 14–18 randomly assigned New Zealand White rabbit eyes and time of dosing recorded. At various time points, 2 animals, at each time point, were euthanized and aqueous humor as well as the ocular tissues collected. The following ocular samples were analyzed: aqueous humor, vitreous humor, conjunctiva, cornea, lens, iris/ciliary body, sclera, retina and choroid. Ocular tissues were combusted and amount of radioactivity determined by Liquid Scintillation Counting (LSC). Aqueous humor samples were transferred to LSC vials directly and amount of radioactivity determined.
Results: :
Peak concentrations of radiolabeled bromfenac were observed in the aqueous humor and most ocular tissues at 2 hours; conjunctiva peaked at 1 hour. Bromfenac concentrations were highest in cornea, conjunctiva and sclera. Similar amounts of radiolabeled bromfenac were detected in aqueous humor, iris/ciliary body, choroid, and to a slightly lesser degree, retina. Bromfenac was observed in all samples at 24 hours ≥ 0.01 µg equivalent/g.
Conclusions: :
Significant penetration of bromfenac was observed in all tissues over 24 hours including the retina and sclera, with peak concentrations on or before 2 hours. These results strongly suggest that XibromTM (bromfenac ophthalmic solution) 0.09% may also be effective in treating inflammation of the sclera, choroid and retina.
Keywords: anterior segment • choroid • retina