Previous studies1 reported from this department have shown that sulfathiazole(2-[paraaminobenzenesulfonamido]-thiazole) after oral administration to cats appears in the aqueous of normal eyes in relatively small quantities. Only 18.4 per cent as much was found in the aqueous as in the blood. On the other hand, sulfanilamide, sulfapyridine (2-[paraaminobenzenesulfonamido]-pyridine) and sulfadiazine (2-[paraaminobenzenesulfonamido]-pyrimidine) attained the high level in the aqueous of 75 to 80 per cent of the level in the blood. Bellows and Chinn2 obtained similar results in dogs. Liebman and Newman,3 working with rabbits, reported comparable data. Because of the low concentrations of sulfathiazole in the ocular tissues it was implied that clinical use of the substance against intraocular infections was probably inadvisable.
Such a restriction of the use of sulfathiazole would be unfortunate, since this drug has certain advantages over other sulfanilamide compounds. It ranks low in toxicity. It is the drug of choice in combating