Hypoglycemic effect of surfactant-coated insulin solubilized in a novel solid-in-oil-in-water (S/O/W) emulsion

A novel solid-in-oil-in-water (S/O/W) emulsion for oral administration of insulin has been developed using surfactant-coated insulin. The S/O/W emulsion prepared by a shirasu porous glass (SPG) membrane provided a sharp size distribution and was stable. Leakage of insulin from the S/O/W emulsions was not observed for several days. The S/O/W emulsion showed the hypoglycemic activity for a long period after oral administration to rats.