Insulin inhalation with absorption enhancer at meal-times results in almost normal postprandial insulin profiles

Conventional insulin therapy with subcutaneous injections of regular insulin at meal-times result in plasma insulin peaks that are lower and appear later than meal related insulin peaks in healthy individuals. The present study was designed in order to evaluate the resulting insulin concentrations in peripheral blood after inhalation of micro crystalline human insulin together with an absorption enhancer [dioctyl sodium sulphosuccinate (DOSS)] via a powder inhaler.

Ten insulin dependent middle-aged non-obese diabetic patients (mean diabetes duration 21 years) were included. Blood samples for glucose and insulin were taken immediately before and 13 times, up to 300 min, after insulin inhalation. The mass median aerodynamic diameter of the particles was 3.2 microm. The inhaled insulin dose was 39 U.

Within 5 min after the end of the 2 min inhalation procedure the mean increase of insulin was 7.0 microU ml-1, and the mean maximum concentration, 12.1 microU ml-1, was reached between 20 and 30 min. There was then a slow decline until base-line was reached after around 210 min and there were no adverse events.

Inhalation of a mixture of 39 U of insulin and enhancer resulted in a rapid plasma insulin peak with a slow decline, similar to the normal postprandial insulin profile.