Distribution, excretion, and metabolism of nitro‐p‐phenylenediamine in rats

Abstract

The distribution, excretion, and metabolism of nitro‐p‐phenylenediamine, a constituent of hair dye, was studied after administration of [¹⁴C/nitro‐p‐phenylenediamine (2.6 mg/30 μCi/kg) to male rats. After intraperitoneal administration, 37.4% of the radioactivity administered was excreted in the urine and 54.3% in the feces within 24 h. After intravenous administration, 42.2% of the radioactivity was excreted in the bile within 24 h. The highest concentration of radioactivity in tissues was found at 1 h, except in the small and large intestines, followed by a rapid decrease in concentration. Only small amounts of radioactivity were found in the tissues 48 h after administration. Some of the radioactive materials in the urine were separated by thin‐layer chromatography and identified as N¹ ,N⁴‐diacetyl‐2‐amino‐p‐phenylenediamine, N⁴‐acetyl‐2‐nitro‐p‐phenylenediamine, and unchanged nitro‐p‐phenylenediamine.