Abstract
Abstract: :
Purpose: To determine the ocular irritation and toxicity potential of various concentrations of Nepafenac Ophthalmic Suspension containing 0.005% benzalkonium chloride (BAK) as a result of subchronic topical ocular administration. Methods: Four groups of 8 cynomolgus monkeys each were randomly assigned to receive either 0.1, 0.3, 1.0% Nepafenac Ophthalmic Suspension containing 0.005% BAK as a preservative or vehicle. Two drops (total 80 microliters) were instilled into the right eye 4 times a day for approximately 3 months. The left eye served as an untreated control. The conjunctiva, cornea, anterior chamber, light reflex, lens, and iris of both eyes in all groups were examined by slit–lamp biomicroscopy prior to dosing and again on Study Days 6, 13, 27, 41, 55, 69, 83, 104, and 111. Indirect ophthalmoscopy, pachymetry, IOP, and specular microscopy of the central corneal endothelium were also performed. Vehicle means were compared with treatment group means to determine statistical differences (Dunnett’s test; P<.05) for IOP, pachymetry and specular microscopy parameters. At the end of the study, ocular tissues were submitted for histopathology. Results: Throughout the study period, slit–lamp biomicroscopy did not reveal treatment–related differences among groups in pupillary light reflex, aqueous flare, aqueous cells, corneal cloudiness, neovascularization, and fluorescein staining. The fundi remained normal. Pachymetry, IOP, and specular microscopy parameters (mean cell density, percent hexagon, or mean cell area) did not reveal treatment–related differences among groups. Histopathology revealed no treatment–related lesions or evidence of ocular irritation in the eyes, adnexa, or nasal–lacrimal tissue of any monkey in any treatment group. Conclusions: Over a 3–month period, 4–times daily dosing with Nepafenac Ophthalmic Suspension 0.1, 0.3, or 1.0% did not induce ocular irritation or ocular toxicity.
Keywords: cornea: basic science • inflammation