Pharmacologic chelators do not effectively penetrate cell membranes and blood-brain barrier. This study assesses methylsulfonylmethane (MSM) as a permeability enhancer and an excipient to facilitate EDTA transport across biologic membranes, and to make possible localized, regional chelation. Topical application of MSM with C(14)EDTA onto the rat cornea led to uptake of the C(14)EDTA in all tested ocular tissues. Without MSM, EDTA did not penetrate the eye. The ability of MSM to deliver EDTA into an eye provides an opportunity for regional chelation therapy. Additionally, these studies suggest that MSM could also be an adjuvant for delivering ciprofloxacin and other chemical compounds to specific, local tissue sites.