SOME PHARMACOLOGICAL PROPERTIES OF UNSYMMETRICAL ETHYL-O-ETHYLPHENYLUREA

¹ From the Burroughs Wellcome & Co. U.S.A. Experimental Research Laboratories, Tuckahoe, N. Y.

1. Unsymmetrical ethyl-o-ethylphenylurea is somewhat more soluble in water, equally effective as a hypnotic and definitely less toxic as judged by relative H 50 and L 50 values than its isomer, unsymmetrical n-propyl-o-tolylurea. Thus, some of the properties, visualized at the onset, were found present in the former.

2. The H 50 dose in albino mice, albino rats and in dogs closely approximate each other, especially when the same sex of each specie are compared, being, respectively, 0.282 mM. (54 mgm.), a little less than 0.26 mM. (50 mgm.) and between 0.26 mM. (50 mgm.) and 0.364 mM. (70 mgm.) per kilogram.

3. Unsymmetrical ethyl-o-ethylphenylurea like other anesthetics tends to lower the body temperature, it has a variable effect on the pulse and respiratory rates and it causes a depression in blood pressure, the extent and duration of which is proportional to the dose administered.

4. In neither chronic nor acute toxicity studies in rats could pathological changes in the blood, heart, liver, kidney or spleen be demonstrated.