Inhalative administration of insulin using a new bubble jet atomization device.

In this study, we attempted to perform inhalative administration of insulin using a new "bubble jet" atomization device based on ink jet printing technology and developed by Canon Inc. The aim of this study was to confirm the usefulness of the new device for achieving a hypoglycemic effect by insulin inhalation in normal rats. Inhaled insulin (15 U/kg) or a control solution without insulin was administrated to each Wistar rat intratracheally using the bubble-jet atomization device. Blood glucose concentrations were measured at 0, 10, 20, 30, 60, 90 and 120 min after administration of insulin or control solution. The blood glucose concentrations in the inhaled insulin group were 63 +/- 10 mg/dl (20 min), 43 +/- 8 mg/dl (60 min) and 35 +/- 9 mg/dl (120 min), while those in the control solution group were 80 +/- 9 mg/dl (p = 0.016), 75 +/- 10 mg/dl (p < 0.001) and 85 +/- 27 mg/dl (p < 0.001). The blood glucose concentrations after administration of inhaled insulin were significantly lower than those after administration of control solution at all time points (p < 0.05) except 0 and 10 min. We confirmed the hypoglycemic effect of inhaled insulin using the new bubble jet atomization device. These results proved that the new device could atomize insulin while maintaining its bioactivity.