Abstract The promoting effect of glyceryl esters of acetoacetic acid on the rectal absorption of insulin and inulin was studied. A decrease in the serum glucose level was observed in rabbits following the administration of an insulin suppository containing glyceryl-1, 3- diacetoacetate (adjuvant II) or 1, 2-isopropylideneglycerine-3-acetoacetate (adjuvant IV). The promoting effects of adjuvants II and IV on the rectal absorption of insulin and inulin ...