Hypoglycemic efficacy of chitosan-coated insulin liposomes after oral administration in mice.
OBJECTIVE
To evaluate the hypoglycemic efficacy of insulin liposomes coated by chitosan with different molecular weights and concentrations after oral administration in mice.


METHODS
Insulin-liposomes were prepared by reversed-phase evaporation. Chitosan coating was carried out by incubation of the liposomal suspensions with the chitosan solution. The hypoglycemic efficacies of chitosan-coated insulin liposomes were investigated by monitoring the blood glucose level using the glucose oxidase method after oral administration to healthy mice.


RESULTS
In all the insulin liposomes, the insulin liposomes coated by 0.2% chitosan (Mr 1000 kDa) showed a better hypoglycemic efficacy as compared with the other liposomes coated by chitosan. The minimum blood glucose level was 15.1%+/-6.0 % of the initial (n=6). The hypoglycemic efficacy lasted for 4 h after oral administration to mice.


CONCLUSIONS
Chitosan-coated liposomes could reduce tryptic digestion on insulin, and enhance enteral absorption of insulin. The molecular weights and concentrations of chitosan had significant effects on hypoglycemic efficacy of chitosan-coated insulin liposomes after oral administration to healthy mice.
Wu
Zheng-hong
ZH
Department of Pharmaceutics, China Pharmaceutical University, Nanjing 210009, China.
Ping
Qi-neng
QN
Wei
Yi
Y
Lai
Jia-ming
JM
D000284:Administration, Oral; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D002686:Chitin / Q000031:analogs & derivatives* / Q000737:chemistry*; D048271:Chitosan; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D016503:Drug Delivery Systems; D007004:Hypoglycemic Agents / Q000008:administration & dosage* / Q000494:pharmacology; D007328:Insulin / Q000008:administration & dosage* / Q000494:pharmacology; D008081:Liposomes; D008297:Male; D051379:Mice; D010316:Particle Size; D013678:Technology, Pharmaceutical / Q000379:methods
D001786:Blood Glucose; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D007004:Hypoglycemic Agents; D007328:Insulin; D008081:Liposomes; D002686:Chitin; D048271:Chitosan