Background and Aims

The primary container that stores the insulin is one of the key elements of the design of an insulin pump. It shall resist to the environmental conditions linked to a home usage, to the aging and ensure the integrity of the insulin. Debiotech designed a reservoir based on a rigid frame with a flexible membrane. The rigid-flexible design of this reservoir prevents over-deliveries of insulin resulting from variations of temperature and pressure increase.

The challenge by using a flexible membrane is to ensure that insulin stored in the container will keep its integrity.

Methods

The test protocol is based on a comparison between insulin in the reservoir of the pump and insulin inside its original vial. The insulin used for this test session was the insulin lispro.

The insulin was collected from the pump at day 0, at day 2, at day 8, at day 14, at day 21 and day 28. Reference vials were also collected at the same times. And an additional original sealed vial was kept in the fridge at 5°C.

Results

Results showed that insulin characteristics such as physical appearance, potency, purity (presence of polymers), presence of high molecular weight products (HMWP), metacresol concentration and pH were all kept within the pharmacopeia criteria.

Conclusions

The introduction of a flexible membrane in the design of the primary container prevents over-deliveries of insulin resulting from variations of temperature and pressure increase. The proposed design is able to store the insulin for at least 14 days by keeping its main properties.