Background and Aims

Background: Intraperitoneal insulin delivery provides more rapid onset of action and shorter duration compared with subcutaneous insulin. These attributes are critical for improving management of diabetes with sensor-augmented pump therapy or automated insulin dosing. We present data on the stability of insulin delivered through a novel system for continuous intraperitoneal insulin infusion (CIPII) using an Insulin Delivery Conduit (IDC) made up of a subcutaneous port and tunneled catheter that is accessed by a customized traditional external pump infusion set in an ex-vivo environment that mimics the intraperitoneal space.

Aim: This study aims to examine three system configurations to evaluate compatibility with insulin over 6 weeks.

Methods

Methods: Each system was maintained at 37°C. Regular insulin was pumped through the IDC using a Medtronic insulin pump at a basal rate of 0.6U/hr and three manual daily 5-unit boluses. Infusion sets and pump cartridges (with fresh insulin) were replaced every 7 days. Samples for all test replicates were collected on Day 1, 7, 14, 21, 28, 35 and 42 just prior to weekly infusion set/pump cartridge replacement, and tested for physical and chemical degradation, using Thioflavin T (ThT) fluorescence and HPLC, respectively.

Results

Results: All insulin samples were negative for ThT response indicating absence of insulin aggregates, and had purity levels greater than 97.3%, which meets specification of less than 6% loss in target purity. Therefore, target acceptance criteria for insulin stability were met.

Conclusions

Conclusion: This novel IDC approach for CIPII is a promising method to effectively deliver insulin without insulin degradation.