THE EXCRETION AND CHARACTERIZATION OF INTRAVENOUSLY ADMINISTERED OLESTRA

Although sucrose octaoleate that is consumed is neither digested or absorbed, following intravenous injection it is found mainly in the liver. Olestra is a mixture of the hexa-, hepta-, and octaesters of sucrose. To follow the metabolic fate of intravenously administered [C-14]sucrose-labeled olestra, we measured its urinary elimination, and the rate of excretion of C-14 in the feces, and characterized the C-14-labeled material that appeared in bile. The fecal excretion for days 4-14 after dosing was found to be first order with the half-life of the injected olestra being 5.0 +/- 0.5 days. The C-14 recovered in the bile was soluble in chloroform. Two-dimensional thin-layer chromatography autoradiograms of the biliary lipid showed the pattern of the biliary C-14 to be essentially the same as that of the dosed olestra. Biliary excretion and subsequent fecal egestion of essentially unhydrolyzed sucrose esters is the principal route for the removal of intravenously administered olestra. Only traces of C-14 were found in the urine.