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Rosoxacin, a new synthetic antimicrobial agent, has a wide spectrum of activity that may prove beneficial in the treatment of ocular infections. To determine the penetration of rosoxacin into ocular tissues and serum of the rabbit after topical, subconjunctival, and intravenous (IV) administration, rosoxacin levels were measured using a microbiological assay after enzymatic digestion of the ocular tissues. Quantities of rosoxacin that should prove to be of therapeutic value were detectable in the anterior segment of the eye after topical or subconjunctival administration. Subconjunctival administration also resulted in high levels in the retina and choroid area and in the optic nerve. Low levels were detected in the retina and choroid 15 minutes following IV injection; however, no detectable levels were found in the ocular tissues after this period.

To our knowledge, this is the first report of a topically applied, specific adenylate cyclase activator that reduces intraocular pressure. Forskolin, a novel adenylate cyclase activator, is reported to increase cyclic adenosine monophosphate (AMP) in intact cells. Cyclic AMP levels are increased with various antiglaucoma agents. Intraocular pressure in rabbits was significantly reduced with two concentrations of forskolin, 0.1% and 0.05%. Ocular hypertension was noted with 0.05% and 0.2%. No change in IOP was noted with 0.01% forskolin. The IOP lowering with 0.1% and 0.05% forskolin lasted approximately six hours. Mild, transient conjunctival chemosis was noted in the doses that decreased IOP. The contralateral control eye showed decreases in IOP, but the differences between control and tested eyes were significant by the Student's paired t test.