Abstract
The blood and tissue levels of unchanged ethchlorvynol (EC) were determined after intraperitoneal administration of EC suspended in 5% polyethylene glycol 400 aqueous solution (5% PEG). Pre-oral administration of 5% PEG did not show any effect on the levels of EC in blood and tissues, compared with the pre-treatment of normal saline as a control. However, pre-administered corn oil as well as peanut oil and soybean oil decreased the brain levels of EC. In order to exclude the effect of the vegetable oils, the thoracic fistula rats were used in the studies. When EC was administered orally in corn oil to the fistula rats, the brain levels of EC were fairly improved, and were higher than in the intact rats. As little as 0.06 and 0.05% of total dose were recovered in the lymph as EC and EC-glucuronide (ECG), respectively after oral administration of EC in corn oil. While both EC and ECG were not detected in the lymph when EC was given in 5% PEG.
