Absorption, fate and excretion of glaziovine-14C in the dog.
The pharmacokinetic parameters of glaziovine, a proaporphine alkaloid with neuropharmacological properties, were investigated in dogs. At alkaline pH, glaziovine-14C showed a very high partition coefficient value from a buffered water solution and both benzene and chloroform. When administered i.v. to both conscious and anaesthetized dogs, levels of glaziovine-14C were higher in the heart, liver, kidneys and brain, and lower in skeletal muscle, skin and plasma. The high amount of radioactivity found in the small intestine as well as that found in bile obtained from a biliary fistula demonstrates that glaziovine is excreted both via the bile and via urine in not dissimilar amounts at least in dogs. When administered orally, peak plasma levels were encountered in 1 hr. Cumulative urinary excretion of glaziovine over a 24 hr period was 49% after the i.v. route and 39% after the oral route. By comparing the percentage of urinary excretion or the area under the plasma level time curve (AUC) obtained in the first 24 hr after i.v. and oral administration, percentages of bioavailability were obtained ranging from 80 to 98%. Glaziovine thus seems to possess a very high enteral absorption.