The absorption metabolism, and excretion of Estracyt (NSC 89199) in patients with prostatic cancer.

Estraumustine phosphate (estradiol, 3-N-[bis(2-chloroethyl)-] carbamate-17beta-dihydrogenphosphate (Estracyt) labeled with 3H in the estradiol moiety and 14C in the carbamate moiety was synthesized, and its absorption, metabolism, and excretion were studied after oral administration to three patients with prostatic carcinoma. One of the patients was also given the same dose by intravenous injection. In addition to monitoring isotope levels in peripheral blood, urine, and feces, samples of portal vein blood were obtained through a catheter in the umbilical vein. Analyses of portal blood samples revealed that most of the estramustine phosphate was dephosphorylated to estramustine during absorption. Estramustine was found to be the major metabolite in peripheral blood after oral as well as after intravenous administration. The urinary excretion data appeared to warrent the conclusion that most of the carbamate ester of estraumustine is hydrolyzed before it is excreted. In the patient given estramustine phosphate by both routes the absorption of the compound when given by mouth was found to be approximately 75 per cent.