Iothalamate ethyl ester as hepatolienographic agent.

In search of a hepatolienographic agent, the iothalamate ethyl ester particulate suspension was prepared with the average particle size of 1.5 mu in diameter. When mixed with plasma of different animal species, the physical properties of the particular suspension changed significantly. The nature of this difference is not understood but is probably related to protein-particle interaction in the different species. Doses of 550 mg iodine per kg body weight as a single intravenous infusion of the particulate suspension resulted in satisfactory opacification of liver and spleen in rats, followed by complete loss of radiopacity within three days. Larger doses resulted in the death of the rats within 12-14 hours. In general, the mice tolerated larger doses than rats, but there was very poor opacification of the liver, despite good opacification of spleen. Further work is being carried out to improve the suspension and to better understand the difference in behavior of the particulate suspension in different animal species.