Intraocular penetration of topically administered acyclovir.

The aqueous and intracorneal levels of acyclovir administered to rabbit eyes were examined utilizing high-performance liquid chromatography. A 3% ointment of acyclovir was administered into the cul-de-sac and 0.1 ml of a 1.5% solution of acyclovir for intravenous application was injected subconjunctivally. The maximum concentrations of the drugs that penetrated into the aqueous and the cornea after ophthalmic ointment administration were 3.38 micrograms/ml at 60 minutes and 45.78 micrograms/ml at 30 minutes after drug administration, respectively. Subconjunctival application showed 15.32 micrograms/ml in the aqueous at 60 minutes and 111.97 micrograms/ml in the cornea at 30 minutes after administration as a maximum concentration, respectively. Relatively high drug concentrations in the cornea after ointment administration and high drug dose penetrations into the eye can be useful clinically. In particular, subconjunctival administration should be a useful treatment for severe herpetic keratitis.