Effect of liposome encapsulation of a fluorescent dye on its uptake by the lymphatics of the rat.
The fluorescent dye carboxyfluorescein (CF), entrapped in liposomes and administered by intraduodenal injection to thoracic duct-cannulated rats, was not detected in thoracic duct lymph at any time after dosing. However, the dye was present in blood, and in higher concentration in portal than in systemic blood. Similarly, free CF given intraperitoneally (i.p.) appeared to be absorbed into portal blood and was quickly cleared from the circulation, with less than 1% of the injected dye being recovered in thoracic duct lymph within 24 h after dosing. In contrast, 27% of the injected CF was recovered in thoracic duct lymph of rats receiving CF/liposomes i.p. These findings indicate that liposomal entrapment effectively limits passage of CF into the splanchnic blood vessels while enhancing the lymphatic uptake of the dye from the peritoneal cavity.
D000818:Animals; D004396:Coloring Agents / Q000008:administration & dosage / Q000378:metabolism*; D004355:Drug Stability; D005452:Fluoresceins / Q000008:administration & dosage / Q000378:metabolism*; D007274:Injections, Intraperitoneal; D007408:Intestinal Absorption; D007441:Intubation, Gastrointestinal; D008081:Liposomes; D008208:Lymphatic System / Q000378:metabolism*; D008297:Male; D010713:Phosphatidylcholines; D051381:Rats
D004396:Coloring Agents; D005452:Fluoresceins; D008081:Liposomes; D010713:Phosphatidylcholines; C024098:6-carboxyfluorescein; C017251:1,2-oleoylphosphatidylcholine