Abstract: AIM: To evaluate the buccal absorption and the effects of absorption enhancers and the enzyme inhibitor on the absorption of insulin.METHODS: The hypoglycemic response was examined by buccal delivery of insulin solution(INS-SOL)and insulinPatch(INS-PAT)co-administered with various absorption enhancers and the enzyme inhibitor in diabetic rats.ThePharmacological bioavailability was used to evaluate the absorption enhancement of INS-SOL and INS-PAT from the buccal cavity under various conditions in comparison with subcutaneous injection.RESULTS: In the absence of enhancers,the bioavailabilities werelow(0.77 %and 1.82 %)after buccal delivery of INS-SOL and INS-PAT.However,the concomitant administration of 3 % sodium deoxycholate(SDCh)and 5 % nonoxinol(NON)appeared to be more effective in increasing the hypoglycemic effect of insulin(P<; 0.05).3 % SDCh had the optimal enhancement,and the bioavalabilities of INS-SOL and INS-PAT were increased by three times(2.84 % and 7.26 %).CONCLUSION: Insulin can be absorbed through the buccal mucous,andProper absorption enhancers canPromote absorption function.

Key words: pharmacology, insulin, buccal absorption, absorption enhancers, buccalPatch, the enzyme inhibitor, sodium deoxycholate, nonoxinol, hypoglycemic effect