[Effect of preoral and transdermal insulin preparations on blood glucose concentration in mice]

Effects of oral and transdermal insulin applications on blood glucose concentration were investigated in nonconditioned, healthy mice. Insulin was applied in a special lipid formulation which contained no chemical enhancers or protease inhibitors. In comparison to control applications with same volumes of insulin free lipid formulations significant and reproducible blood sugar lowering effects were found with the insulin-lipid formulation. Additional control applications of the same dosages of oral aqueous insulin solutions differed only slightly to the insulin free lipid formulations. Same dosages of s.c.- and p.o.-applications of the insulin-lipid-formulation induced quantitatively comparable blood sugar lowering effects. The maximum oral effects showed dose dependence in a dose range of 0.7 to 9.5 IU/kg bodyweight. Maximal effects after oral application were seen 1-2 h after oral application. Investigations with transdermal insulin applications showed also significant effects in lowering blood glucose concentrations, but these effects were weaker than after oral application and showed a delayed onset.