Corneal penetration of rifampin.
We tested the corneal penetration of rifampin in four vehicles: dimethylsulfoxide, polyethylene glycol, an ocular lubricant, and as rifampin ointment. We measured drug concentrations in the aqueous humor in rabbits after topical instillation of 1 and 2.5% rifampin according to two dosage schedules. Drug concentrations in the aqueous humor were bactericidal to Mycobacterium leprae. Since leprosy of the cornea, iris, and ciliary body may develop despite standard systemic bacteriostatic treatment, treatment of leprotic involvement of the anterior eye may be enhanced by intensive topical application of rifampin.