Cool Chain Drugs | What are Cool Chain Drugs?

A cold chain is a temperature-controlled supply chain. An unbroken cold chain is an uninterrupted series of refrigerated production, storage and distribution activities and associated equipment which maintain a given low-temperature range. It is used to preserve and to extend the shelf life of products such as fresh agricultural produce, seafood, photographic film, chemicals, pharmaceutical drugs and other medical and biological agents. It is important that the formulator of a pharmaceutical product understands the effect of temperature on the product, so as to maintain its efficiency, structure and safety. If the cold chain is broken by allowing transported material to warm up, even for a short time, the effect can be seriously damaging not only on the structure and form of the products but also on their efficacy and safety, It is necessary therefore to understand how the storage and delivery of the products from one location to another are likely to impact on their performance. To assist in this process, standard operating procedures (SOPs) and guidelines are published by health authorities such as the Federal Drug Agency (FDA) in the USA and other regulatory organizations. The FDA covers cool chain drugs under the Code of Federal Regulation —Title 21, Section 211.94(b). This defines the container type, for example, that should be used to maintain and control the temperature of products within standard limits.

There is some dispute in the literature regarding terminology. Cold chains may be called cool chains and products that are transported in cold chains are often called ‘cool products’. Some experts from health agencies and the FDA suggest that the term ‘controlled room temperature’ or CRT better indicates the care that should be afforded to these products.

The cold chain distribution process is an extension of the good manufacturing practice (GMP) environment that all drugs and biological products are required to adhere to, enforced by the various health regulatory bodies. As such, the distribution process must be validated to ensure that there is no negative impact to the safety, efficacy or quality of the drug substance. The GMP environment requires that all processes that might impact the safety, efficacy or quality of the drug substance must be validated, including storage and distribution of the drug substance.

What would happen if the temperature is not controlled?

The US FDA requires that all cool chain products should be maintained according to the within specified temperature limits. If there is an imbalance or no control, the drugs may become adulterated resulting reducing the quality of the product. This is also covered in Section 501 (a) (2) (B) of the Federal Food, Drug and Cosmetic Act.

The therapeutic effects of certain drugs are changed markedly if the temperature of the cool chain is not controlled. For this reason regulatory authorities such as the FDA may take action on the drug supplier if cool chain standards are not maintained. An example would be in the case of drugs or vaccines intended for diabetic patients where uncontrolled storage and distribution temperatures of the drugs may lead to harmful side effects when administered to a patient.

Temperature Limits

Traditionally all historical stability data developed for vaccines were based on the temperature range of 2–8 °C (36–46 °F). This range has been adopted by the FDA for pharmaceutical products, and is now generally accepted for all biological agents and drugs.

Shipping and storage

The processes for handling the shipping and storage of cold chain drugs is constantly evolving as new technology emerges. Monitoring and validating the cold chain – distribution and storage – is essential, and GPS sensors are available that can track temperatures throughout the chain from production to end use. Standard Operating Procedure (SOP) guidelines have been published by regulatory bodies which should be followed with respect to shipping. Products can be transported in special vacuum-insulated containers, in which ice packs are used to control the temperature. Should drugs be transported in refrigerated vehicles or stored in electrically refrigerators, the thermostat should be set between 2 and 8°C. Temperatures need to be checked regularly and documented. In the case of storage in remote locations, emergency back-up power needs to be available there be a power failure which would cause the temperature to rise above the 8°C upper limit. Indeed, there are continuing concerns in maintaining cold temperatures when transporting and storing vaccines and drugs to remote locations, such as central Africa.