AIM To investigate the possibility of the enhancing effect of flexible nanoliposomes on buccal delivery of insulin. METHODS
Two kinds of liposomes (flexible nanoliposomes and conventional liposomes) were prepared by reverse-phase evaporation methods. The liposomal entrapment efficiency was determined by column chromatography. The particle sizes and the morphology of the liposomes were also evaluated. The hypoglycemic effect and the changes of insulin concentrationin vivo of insulin liposomes on rabbits were investigated. RESULTS The entrapment efficiencies of the flexible and conventional liposomes were (18.9±1.8)% (n=3) and (22.1±2.2)% (n=3), respectively. The particle sizes of the flexible and conventional liposomes were (42±20) nm and (60±34) nm, respectively. There were no significant differences of appearance between two liposomes. Compared to subcutaneous administration of insulin solution, the
relative pharmacological bioavailability and the
relative bioavailability of insulin-flexible nanoliposomes group were 15.59% and 19.78%, respectively. The insulin-flexible nanoliposomes group was higher than both insulin conventional liposomes group (P<0.05) and blank flexible nanoliposomes and insulin mixture group (P<0.05).CONCLUSION The flexible nanoliposome may be a better carrier for buccal delivery of protein drugs than the conventional liposome.