Comparison of disappearance from blood and lymphatic delivery of human fibroblast interferon in rat by different administration routes.

Abstract

Disappearance from the blood and lymphatic delivery of human fibroblast interferon (HuIFN-β) in rats by the various administration routes were studied. Intravenous injection showed a rapid disappearance of HuIFN-β from the blood circulation, however, the clearance rate was greatly decreased after 2 h and the half-lives were 15 min and 2.0 h. Intramuscular, subcutaneous and intraperitoneal injections maintained readily detectable levels in the blood for 12 h, and the half-lives were 2.3, 1.7 and 1.2 h, respectively. Lipid-surfactant mixed micelles greatly promoted the absorption of HuIFN-β from the large intestine with extremely high selective lymphatic delivery, whereas intravenous and intramuscular injections showed no selective transfer into the lymphatics.