Managing the Cold Chain

Cold chain management is vital in many industries, but particularly in the transportation of vaccines, insulin and blood. Managing the cold chain requires keeping a product within a particular temperature range throughout the supply chain. This presents many challenges for pharmaceutical companies, government health agencies, transportation providers, and health care practitioners.

In the pharmaceutical industry, management of the cold chain may eventually become a regulatory function (1). The Parenteral Drug Association’s Pharmaceutical Cold Chain Discussion Group in Bethesda, MD has issued draft guidance on cold chain management.

Considerations
Multiple factors must be considered in designing a cold chain. These include:

• Temperature tracking – Even in refrigerated units, temperatures can vary. Temperature tracking is important to confirm appropriate temperature throughout.
• Selection of containers – Container selection influences temperature variation within the unit.
• Transportation provider’s ability – Whil, the availability of temperature-controlled transportation is increasing, it is still necessary to look at experience and what processes the transportation company has in place.
• Distribution route – Certain transportation routes experience greater temperature variation or higher average temperatures than others. A more stable external temperature influences the internal stability.

• Contingency Plans – Decisions about route, provider, container and tracking can help in the development of contingency plans, but it is important to think about backup should equipment not work, or transportation take longer than expected.

The Role of Packaging (1)

The role of packaging can provide a buffer against variations in the distribution network. Packing that includes insulation, temperature-tracking equipment, and some form of coolant creates additional insurance in the cold chain. One simple temperature gauge that can be used is the pressure-sensitive label. Once the label is exposed to specific conditions, the label changes color alerting the supply chain of a disruption in the cold chain. More sophisticated alternatives are also available that digitally track temperature throughout the transportation process. Many feel that these digital solutions are not cost effective (2).

Consequences

The importance of maintaining temperature is high. In the case of vaccines, the World Health Organization reports that manufacturers only test the potency within certain temperature ranges. Efficacy outside of these ranges is unproven. Additionally, experts note that vaccines are live organisms and require refrigeration. The organisms die and become ineffective outside of the refrigerated conditions. Almost half of all vaccines are wasted as a result of failures to keep the treatment in the proper temperature range (3).

Local Solutions

Administering vaccines for humanitarian aid is difficult in rural areas of developing countries, as there is often no electricity to operate refrigeration units. One solution to this challenge has been the development of a solar powered refrigerator. Models introduced in the last five years have proven themselves by passing UNESCO’s requirements for 5 days of power provided by solar energy (4). This technology helps to establish that the cold chain can be maintained, even under complicated conditions.

Evaluation of the cold chain is an ever-evolving process and will become more necessary should standards be instituted for the pharmaceutical and other industries. This will not only help insure the quality of the product, but also reduce costs of wasted goods and materials.

References

(1) Forcinio, Hallie. “Temperature-Sensitive Products.” Pharmaceutical Technology. March 2004.

(2) Kevan, Tom “Theft and terror threats push sensors into the supply chain.” Frontline Solutions. September 2004.

(3) Shetty, Priva Zero refrigeration vaccine trials begin. October 20, 2004.

(4) Powell, Peter “Something new under the sun.” Air conditioning, heating and refrigeration news. April 7, 2003.