[Mechanisms of action of transportation of liposomes and chitosan-coated liposomes containing leuprolide across intestine and Caco-2 cell].
OBJECTIVE
To investigate the mechanisms of action of transportation of liposomes and chitosan-coated liposomes containing leuprolide across rat intestine and Caco-2 cell.


METHODS
Everted-gut technique and Caco-2 cell were used to study the transport properties of free leuprolide, liposomes and chitosan-coated liposomes containing leuprolide. Caco-2 cell was used to study the effect of chitosan concentration and the order of addition on the permeation of liposomes.


RESULTS
The transport of leuprolide was passive diffusion. Probably because the entrapment by liposomes prevents the transport of leuprolide across the rat intestine and Caco-2 cell, the permeation amount of leuprolide from liposomes was lower than that of the free drug. However, liposomes protected the leuprolide from degradation. Chitosan promoted the transport of leuprolide from liposomes and there was no obvious difference in enhancement effect from the concentration of 0.1% to 0.5%. On the other hand, the incubation of chitosan with liposomes may weak the enhancement effect of chitosan.


CONCLUSIONS
Chitosan-coated liposomes showed both protection and enhancement effect, therefore, they may promote the oral absorption of leuprolide.
Guo
Jian-xin
JX
Department of Pharmaceutics, China Pharmaceutical University, Nanjing 210009, China.
Ping
Qi-neng
QN
Dong
Jun
J
Li
Zheng-rong
ZR
Li
Chao-jun
CJ
D000818:Animals; D018931:Antineoplastic Agents, Hormonal / Q000008:administration & dosage / Q000493:pharmacokinetics*; D001692:Biological Transport / Q000187:drug effects; D018938:Caco-2 Cells; D048271:Chitosan / Q000737:chemistry / Q000494:pharmacology*; D004337:Drug Carriers; D016503:Drug Delivery Systems; D006801:Humans; D007583:Jejunum / Q000378:metabolism*; D016729:Leuprolide / Q000008:administration & dosage / Q000493:pharmacokinetics*; D008081:Liposomes; D010316:Particle Size; D010539:Permeability; D051381:Rats; D017207:Rats, Sprague-Dawley
D018931:Antineoplastic Agents, Hormonal; D004337:Drug Carriers; D008081:Liposomes; D048271:Chitosan; D016729:Leuprolide