Insulin Aspart by Jet Injection Enhances Absorption

Senior author Bastaan de Galan, PhD, from the Department of Internal Medicine, Radboud University, in the Netherlands stated that, "We found that the jet injector greatly enhanced the rate of insulin absorption, resulting in a truly immediate onset of action and approximately halving of the time to reach maximal glucose-lowering effect, in comparison with conventional insulin administration."

The authors note that even though rapid-acting insulin analogs have clearly advanced glycemic control in both type 1 and type 2 diabetes, their pharmacologic profile still falls short of mimicking the physiologic effects of endogenous insulin release. It usually takes more than 90 minutes for insulin, delivered conventionally, to reach maximal effect, and the duration of significant hyperinsulinemia often exceeds 3 hours.

Because of that, the authors note, the risks for immediate postprandial hyperglycemia and late postprandial hypoglycemia remain relatively high in patients with diabetes who are treated with rapid-acting analogs. Studies have shown that if insulin is absorbed faster, it may help reduce those risks and more closely approximate the effects of endogenous insulin release.

Using a randomized, double-blind, double-dummy, crossover study design, the researchers assessed the rates of absorption of insulin in 18 healthy volunteers. They performed euglycemic glucose clamp tests in the volunteers after each was administered 0.2 units/kg body weight of aspart, either via jet injection or conventional pen device.

They found that when insulin was administered with the jet injector compared with conventional pen, the time to maximal glucose infusion rate was significantly shorter (51 ± 3 vs 105 ± 11 minutes; P < .0001). It also took less time for peak insulin concentrations to be achieved (31 ± 3 vs 64 ± 6 minutes; P < .0001). Peak insulin concentrations were increased (108 ± 13 vs 79 ± 7 mU/L; P = .01) when insulin was given via jet injection compared with a pen.

The researchers also say that injector insulin administration reduced the time to 50% glucose disposal by approximately 40 minutes (P < .0001).

They found no differences between the devices in terms of maximal glucose infusion rate, total insulin absorption, or total insulin action.

"Our study convincingly shows the pharmacokinetic and pharmacodynamic superiority of jet injection over conventional needle pens for administration of rapid-acting insulin at a dose that is realistic for many people with type 1 or type 2 diabetes," they write.

They also say this study is the first to compare jet injection technology with insulin pens, which most patients prefer over syringes because they are easy to use and deliver a high level of accuracy.

Diabetes Care, July 6, 2011