Hypoglycemic efficacy of chitosan-coated insulin liposomes after oral administration in mice.

AIM

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.

CONCLUSION

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.