Evaluation of regular insulin adsorption to polypropylene bag and polyvinyl chloride infusion set

Clinical application of insulin infusion therapy is usually accomplished with regular human insulin. It is known that the regular insulin adsorbed to the hydrophobic surfaces and different approaches were implemented into the clinical practices. It was aimed to evaluate the rate of adsorption of insulin to polypropylene (PP) bags and polyvinyl chloride (PVC) infusion sets and stability of insulin during the infusion.

A 100 IU insulin was added to PP bags containing 100 mL of 0.9% NaCl solution (n = 6). The infusion was started at a rate of 2 mL/h using infusion sets in the PVC structure. Insulin quantification was performed in the samples taken both from the bag and from the end tip of the infusion set during infusion. The stability of insulin solutions stored at room (+25°C) and refrigerator (+4°C) temperatures were compared. Samples were analysed using reverse-phase high-performance liquid chromatography.

No statistically significant difference was found between the concentrations of the samples taken from the bags stored at room and refrigerator temperatures at the 4th, 12th, and 24th hours (P > .05). It was seen that the adsorption rate of insulin to PVC set was 57% and PP bags is at most 5% at the 24th hour.

When PP bags are used for insulin infusion, it is predicted that 24-hour change can be made instead of frequent change. In addition, losses caused by the high rate of insulin adsorption to PVC infusion sets should be considered and PP infusion sets would be the better option to use if available.