Most refrigerated medicines travel between 2 and 8 °C; vaccines, insulin and many biological products are among them. Even so, it is not a rule for every medicine: the transport condition is set by the outer packaging and the authorised product information, and some medicines are stored at room temperature.
For pharmaceuticals, three things define what the cold chain is: a narrow band, risk in both directions and an unbroken record.
The band runs both ways
A product that warms can lose stability, and one that freezes can lose its structure. Aluminium-adjuvanted vaccines are freeze-sensitive, and freezing can lower potency irreversibly. The vial looks the same from outside; whether the contents still work is not visible. So the logic of the colder the better fails in medicine; the target is staying inside the band.
What GDP asks
The EU Good Distribution Practice guidelines (2013/C 343/01, chapter 9) and the TİTCK GDP guideline (section 10.2) require the storage conditions defined for the product or stated on its outer packaging to be kept in transit, and any deviation to be reported to the distributor and the recipient. Packaging is chosen on the expected external temperature extremes, the longest transport time including waits at customs, and the qualification status of the packaging; temperature mapping takes seasonal variation into account.
With passive packaging, cool packs are placed so they do not touch the product directly, frozen and chilled packs are kept apart, and the seasonal packing configuration sits in a written procedure. One reading at dispatch and one at arrival does not show the exposure in between; a temperature record near the product does. After a deviation, the product is not accepted into stock without a risk assessment showing its integrity.
