Insulin compatibility with polymer materials used in external pump infusion systems

Area of Science:

• Pharmaceutical Science
• Materials Science

Background:

• Insulin pump therapy is a common treatment for diabetes.
• The materials and sterilization methods of infusion sets can potentially affect insulin quality.

Purpose of the Study:

• To assess the impact of different external insulin pump infusion set materials and sterilization methods on insulin quality.
• To identify which infusion set components and processes maintain insulin stability.

Main Methods:

• Insulin quality was analyzed using high-performance liquid chromatography (HPLC).
• Two types of infusion sets were tested: PVC/rubber with PVC catheter (gamma irradiation) and polyethylene/polypropylene with polyethylene catheter (ethylene oxide sterilization).
• Insulin solutions were passed through the sets under simulated user conditions.

Main Results:

• The PVC infusion set significantly reduced preservatives to below 30% and increased insulin transformation products (2-3x baseline).
• The polyethylene/polypropylene infusion system showed minimal preservative loss and no significant increase in insulin transformation.
• Gamma irradiation of PVC catheters was detrimental to insulin stability, while ethylene oxide sterilization of polyethylene catheters did not affect it.
• These effects were independent of insulin brand and zinc content.

Conclusions:

• Gamma-irradiated PVC infusion sets compromise insulin quality, impacting therapeutic efficacy.
• Ethylene oxide-sterilized polyethylene infusion sets are suitable for maintaining insulin stability in external insulin pumps.
• Material selection and sterilization methods are critical factors in insulin pump infusion set design.