INFLUENCE OF BILE-SALTS ON THE PERMEABILITY OF INSULIN THROUGH THE NASAL-MUCOSA OF RABBITS IN COMPARISON WITH DEXTRAN DERIVATIVES

Nasal drug absorption and the effect of absorption promoters have been studied in rabbits. Nasal mucosa excised from rabbits was mounted as a flat sheet in an in vitro chamber. The increase in the membrane permeability coefficient for sodium chloride indicates the change in the porosity by pretreatment with bile salts. The permeabilities for dextran derivatives were enhanced by pretreatment with sodium glycocholate (GC). The permeability coefficient (P) for fluorescein isothiocyanate diethylaminoethyl dextran (FITC DEAE-dextran, DE) was higher than that for FITC-dextran (DT), and P for FITC dextran sulfate (DS) was lower than that for DT with the same molecular weight. Comparing insulin with dextran of the same molecular weight as insulin, the value of P for insulin induced by pretreatment with GC was higher than that for hydrophilic dextran. The partition coefficient seemed to have much more effect on the nasal membrane transport than the molecular weight of the penetrant.