Retinal Delivery of Sodium Fluorescein, Budesonide & Celecoxib Following Subconjunctival Injection

ABSTRACT Purpose: To determine whether sodium fluorescein, budesonide, and celecoxib can be delivered to the retina following subconjunctival administration in the rat. Methods: The solutions of sodium fluorescein, budesonide and celecoxib (75 µg dose) with 5% w/v cyclodextrin were injected subconjunctivally in one eye of the anesthetized male Sprague Dawley rats. The animals were euthanized, and the eyes were enucleated at the end of 15 minutes. Concentrations of budesonide and celecoxib in the extracts of sclera-choroid, retina, vitreous, lens, and cornea were estimated using an HPLC assay. Sodium fluorescein was extracted from the tissues and quantified using a spectrofluorometer. Results: All three drugs reached the retina and the other ocular tissues tested, with the drug levels being the lowest in the lens and the highest in the sclera-choroid. The retinal concentrations of the drugs were in the order: budesonide > sodium fluorescein > celecoxib. Conclusion: Upon subconjunctival injection, the three drugs accumulated in the retina to varying degrees, with no apparent relationship to the drug lipophilicity.