Source of Cold-chain freight

{{Infobox concept | name = Cold-chain freight | subtitle = Logistics | image = cold-chain.svg | caption = A passive shipper holds temperature for a designed duration, not indefinitely. | Passive systems = Insulation plus phase-change material | Active systems = Powered refrigeration | Evidence of performance = A temperature record, not a cold pack }} '''Cold-chain freight''' is transport under controlled temperature. For peptides it is used to limit the degradation routes — [[Deamidation|deamidation]], oxidation, [[Peptide aggregation|aggregation]] — whose rates rise with temperature, and its performance is a matter of record rather than of appearance.{{r|ich_q1a}} A passive shipper is insulation plus a phase-change material, designed to hold a temperature range for a stated duration under a stated ambient profile. It does not hold indefinitely, and a shipment that takes longer than the design duration is outside the qualification whatever the pack looks like on arrival.{{r|usp1079}} The presence of a cold pack is therefore not evidence that a cold chain was maintained. The evidence is a temperature record, from a logger or an indicator, covering the whole of transit. See [[Temperature excursion]].{{r|usp1079}} == Passive and active systems == Passive shippers are qualified by testing against defined ambient profiles: a summer profile, a winter profile, and a duration. Qualification states what the system will do under those conditions, and nothing about what it will do outside them.{{r|usp1079}} The coolant matters. Gel packs conditioned to refrigerator temperature hold a chilled range; frozen packs can take contents below the intended range, and freezing is a distinct hazard for a solution. Phase-change materials formulated to melt at the target temperature avoid both extremes. Active systems maintain temperature by refrigeration and can hold it as long as they are powered. They are used for high-value or long-duration shipments and are uncommon in research-chemical supply.{{r|ich_q1a}} == Monitoring == | Device | What it records | |---|---| | Single-use threshold indicator | Whether a threshold was crossed | | Time–temperature indicator | Cumulative exposure above a threshold | | Electronic data logger | A full temperature profile with timestamps | | Nothing | Nothing | A threshold indicator that has not tripped establishes that a specific threshold was not crossed, which is genuinely informative and is much less than a profile. A logger record is the strongest evidence available and is uncommon outside pharmaceutical distribution.{{r|usp1079}} Reports submitted to this wiki that mention temperature control most often mention the state of the coolant on arrival. That is a weak observation: a pack can be solid on arrival after a period at ambient if it was frozen at dispatch, and can be liquid on arrival without the contents having exceeded the intended range.{{r|reports}} == How much it matters for a lyophilised peptide == Degradation rates in the dry solid are much lower than in solution. A lyophilised peptide is considerably more robust to a transit excursion than a reconstituted one, and short excursions at moderate temperature are unlikely to produce a measurable change.{{r|ich_q1a}} This is not a reason to disregard the cold chain, but it does bear on interpretation. An unfavourable [[Third-party testing|independent result]] on material shipped without temperature control is weak evidence about the supplier, because the material's history is unknown — the asymmetry described at [[Chain of custody]]. The stability statement on a [[Certificate of analysis|certificate]] is written against a named storage condition. A material stored or shipped outside that condition is outside the statement, and the certificate does not describe it.{{r|usp1503}} == References == {{reflist}} <ref name="ich_q1a">International Council for Harmonisation, ''Q1A(R2): Stability Testing of New Drug Substances and Products'' (2003).</ref> <ref name="usp1079">United States Pharmacopeia, General Chapter <1079>, ''Risks and Mitigation Strategies for the Storage and Transportation of Finished Drug Products''.</ref> <ref name="reports">PeptidePedia Wiki community test-report tally, 2024–2026 (self-reported; see [[Project:Sourcing_guidelines]]).</ref> <ref name="usp1503">United States Pharmacopeia, General Chapter <1503>, ''Quality Attributes of Synthetic Peptide Drug Substances''.</ref> == See also == * [[Cold chain]] * [[Temperature excursion]] * [[Chain of custody]] * [[Peptide stability table]] * [[Customs seizure]] {{DEFAULTSORT:Cold-chain freight}} [[Category:Logistics]] [[Category:Cold chain and stability]] [[Category:Manufacturing and supply]]