Pharmacokinetics of ethynyl estradiolsulfonate in minipigs

The pharmacokinetics of ethynyl estradiolsulfonate labelled with 3H in the steroid nucleus and with 14C in the isopropylsulfonic acid side chain was investigated in male minipigs. The plasma level after intravenous administration was interpreted according to a three-compartment model. After oral administration the first two phases were overlapped by the absorption period. The renal and fecal excretion of the two labellings were investigated. In urine the majority of the 3H-labelled steroid was excreted in the unconjugated and in the glucuronide fractions. More than 70% of 14C in urine was unextractable.