Pharmacokinetics and targeting property of TFu-loaded liposomes with different sizes after intravenous and oral administration

The purpose of the study was to develop the liposomal formulations of TFu for oral and intravenous (i.v.) administration, clarify the biodistribution characteristics and in vivo pharmacokinetic behaviors of TFu-loaded liposomes. Four TFu-loaded liposomes of different sizes were prepared and characterized. The pharmacokinetic characteristics and the biodistribution of TFu-loaded liposomes with different sizes were investigated after i.v. or oral administration to mice. The pharmacokinetic studies indicated that TFu-loaded liposomes with different sizes all resulted in higher bioavailabilities than the TFu suspension after oral administration, and the gastrointestinal absorption increased with the reduction in liposome sizes. Following i.v. administration to mice, larger TFu-loaded liposomes (530 and 400 nm) showed higher hepatic and splenic targeting properties and lower cardiac and renal accumulations, while smaller sized liposomes (180 nm) significantly enhanced drug plasma concentration, bioavailability and prolonged retention time in circulation. Therefore, it can be concluded that both the oral and the injectable TFu-loaded liposomes are promising anticancer formulations for improved bioavailability; larger sized liposomes are potential passive targeting therapeutic agents for hepatoma and splenoma through i.v. administration while smaller liposomes might be preferable for oral administration due to its enhancing oral absorption possibility. Consequently, TFu-loaded liposomes with different sizes might have different clinical applications according to different goals of treatment.