Spreading Property of Azoproteins in the Dermis

1. Azoproteins are shown to have the property of spreading when introduced intradermally into the rabbit skin. 2. The aromatic derivative selected for the coupling does not affect specifically the spreading property of the azoprotein. Likewise, the type of protein has no importance, except in quantitative respects. 3. The spreading property conferred upon a protein by coupling appears to derive from the presence of the azo group. 4. The spreading power of an azoprotein preparation seems to be determined by the number of diazo groups which enter the protein molecule, and to vary in direct proportion with the concentration of the solution. 5. Azo compounds of low molecular weight fail to exhibit any significant effect on skin permeability.