Comparative Activities of Thyroxine and its Monosodium and Disodium salts

Abstract

The activities of thyroxine (free-acid) and its monosodium and disodium salts have been compared when admd. by subcut. and oral routes in rats. The method used was thiouracil method of Dempsey and Astwood. No differences were found when the 3 compounds were admd. by the same routes. All 3 compounds were more active when admd. subcut. as compared with oral ingestion. Approx. 65% of the orally admd. hormone was absorbed as judged by the activity when given subcut.