Primary Local Anesthetic Testing and Acute Toxicity of N,N′-Disubstituted 2,3-Diamino-2′,6′-propionoxylidides

Abstract Eight N , N ′-disubstituted 2,3-diamino-2′,6′-propionoxylidides and 1- tert -butyl-2-aziridinecarboxy-2′,6′- xylidide were prepared and tested for local anesthetic activity in the rat sciatic nerve block and in the guinea pig wheal. The durations in the rat sciatic blocks fell between those for lidocaine and tetracaine, but none of them possessed the long duration of tetracaine in the guinea pig wheal. All compounds were more toxic than tetracaine intraperitoneally in the mouse but, except for the aziridine compound, were less irritating than tetracaine in the rabbit intradermal wheal.