I checked, and found that USP grade EDTA still contains up to 0.1% of formaldehyde. Now, L-carnosine in the eye drops will probably convert that into methylamine, but methylamine is also toxic, and it can revert back to formaldehyde through oxidation. So my dilemma is: How do we get rid of traces of formaldehyde and traces of methylamine? What should we add to the eye drop? Maybe, glutathione, or vitamin C. Or maybe, something else?