Stability of Insulin Aspart in Normal Saline Infusion

Aim: To investigate the stability of insulin aspart in sodium chloride 0.9% (normal saline) during storage and continuous IV infusion. Method: Five bags containing insulin 0.1 unit per mL were prepared for each of the four different experimental conditions - room temperature, 37 degrees C, 2 to 8 degrees C, and within an IV administration set. Insulin was assayed by high pressure liquid chromatography. Results: The insulin concentration fluctuated for 4 hours and then remained within the prescribed range over a 24 hour period at both room temperature and 37 degrees C. When stored at 2 to 8 degrees C for eight days, the concentration remained stable after one day and was always within the prescribed range. Infusion through an administration set provided a stable concentration after the initial first hour of infusion. Conclusion: Insulin aspart can be produced in batches in normal saline, stored at room temperature or 37 degrees C for 24 hours or in the refrigerator for eight days, and administered without significant change in the prepared concentration.