Refrigerator
Refrigerator

Cold chain

A cold chain or cool chain is a temperature-controlled supply chain. An unbroken cold chain is an uninterrupted series of refrigerated production, storage and distribution activities, along with associated equipment and logistics, which maintain a desired low-temperature range. It is used to preserve and to extend and ensure the shelf life of products, such as fresh agricultural produce, seafood, frozen food, photographic film, chemicals, and pharmaceutical drugs. Such products, during transport and when in transient storage, are sometimes called cool cargo. Unlike other goods or merchandise, cold chain goods are perishable and always en route towards end use or destination, even when held temporarily in cold stores and hence commonly referred to as cargo during its entire logistics cycle.
Cold chains are common in the food and pharmaceutical industries and also in some chemical shipments. One common temperature range for a cold chain in pharmaceutical industries is 2 to 8 ĀC (36 to 46 ĀF), but the specific temperature (and time at temperature) tolerances depend on the actual product being shipped. Unique to fresh produce cargoes, the cold chain requires to additionally maintain product specific environment parameters which include air quality levels (carbon dioxide, oxygen, humidity and others), which makes this the most complicated cold chain to operate.
There have been numerous events where vaccines have been shipped to third world countries with little to no cold chain infrastructure (Sub-Sahara Africa) where the vaccines were inactivated due to excess exposure to heat. Patients that thought they were being immunized, in reality were put at greater risk due to the inactivated vaccines they received. Thus great attention is now being paid to the entire cold chain distribution process to ensure that simple diseases can eventually be eradicated from society.
The overall approach to validation of a distribution process is by building more and more qualifications on top of each other to get to a validated state. This is done by executing a component qualification on the packaging components, an operational qualification to demonstrate that the process performs at the operational extremes and finally a performance qualification that demonstrates that what happens in the real world is within the limits of what was demonstrated in the operational qualification limits.
Thus the process is continually evolving and correcting for anomalies that occur in the process. Eventually the process can evolve into periodic monitoring once sufficient data demonstrates that the process is in a state of control. Any anomaly that occurs once a process is in a state of control may result in the process being invalidated and not in control and could potentially result in product withdraw from the market to ensure patient safety. A formal product withdraw is only done when the quality, safety or efficacy of a product is questionable. A single anomaly would not necessarily require a product withdraw if there is sufficient stability data that demonstrates that excursions will not affect product quality.