Tolerance of N-chlorotaurine, an endogenous antimicrobial agent, in the rabbit and human eye--a phase I clinical study.

N-chlorotaurine (NCT), an essential weak oxidative N-chloro compound produced by stimulated human leukocytes, shows bactericidal, fungicidal, virucidal and vermicidal efficacy. A double-blind, randomized and placebo controlled study was done to evaluate the tolerance of the aqueous NCT solution by application to rabbit and human conjunctiva. In six rabbits treated with 1% and 3% NCT regimen for nine days no ocular and behaviour changes could be observed. In a pilot study with two volunteers, treatment with 2.8% NCT for five days caused a self-limited conjunctival injection of one subject, while 1% NCT was well tolerated. Subsequently, eight healthy volunteers participated in a phase I clinical study. One percent NCT was applied for five days and was well tolerated by all subjects except for minimal eye burning after the application. Because of these positive results, usage of the antimicrobial agent NCT in ophthalmology is suggested.