Temperature mapping
Storage areas should be temperature mapped to identify the range of conditions across the space, including the worst-case locations, before monitoring positions are fixed. Monitoring devices placed without a mapping study cannot be shown to be measuring the right place.
Mapping should cover the seasonal extremes the area will experience, and should be repeated after changes that could alter the profile — new racking, changed stock density, HVAC modification, a new door, or a change in the way the space is used.
Mapping reports that are several years old and predate visible physical changes are a common finding.
Monitoring and alarms
Continuous monitoring with recorded data is the expectation for controlled storage. The system should alarm on excursion, and the alarm needs a defined response including out-of-hours coverage. An alarm that sounds in an empty building on a Saturday is not a control.
Records should show that alarms were acknowledged and acted on, not merely that they occurred. Alarm logs with no corresponding response records are a recurring inspection theme.
Calibration
Monitoring and measuring devices should be calibrated at defined intervals against traceable standards, with certificates retained. Where a device is found out of calibration, there should be a documented assessment of the impact on the data it produced since its last valid calibration.
That retrospective impact assessment is frequently omitted, and it matters because it determines whether stock stored during that period can still be considered evidenced.
Transport and shipper validation
Chapter 9 requires that the required storage conditions are maintained during transport. For passive shipping systems this means the packing configuration must be validated for the routes and ambient conditions it will face — including the duration, the seasonal extremes and the specific arrangement of coolant and product.
A validated configuration is only valid as packed. Deviations in coolant conditioning, product quantity or pack-out sequence invalidate the study, which is why packing instructions and packer training matter as much as the shipper itself.
What a shipper validation should define
- Ambient profiles tested, covering summer and winter extremes.
- Maximum transit duration the configuration supports.
- Minimum and maximum product load.
- Coolant type, quantity and required conditioning.
- Exact pack-out arrangement, with an instruction staff can follow.
- Whether a monitor travels with the shipment and how it is reviewed on arrival.
Third-party carriers
Using a carrier does not transfer the obligation. Chapter 7 treats transport as an outsourced activity requiring a written contract that defines GDP responsibilities, and the provider should be assessed before use and monitored afterwards.
Practical oversight includes reviewing the carrier's temperature data rather than accepting assurances, agreeing how excursions in transit are reported and within what timeframe, and periodically auditing the provider.
Arrival checks
Temperature-sensitive deliveries need a defined receipt check that includes reviewing the transit monitoring data before the stock is placed into saleable storage. Booking stock in first and reviewing the data later creates a window where unassessed product is available to pick.
Common questions
- How often should storage areas be re-mapped?
- There is no fixed interval. Re-mapping should follow change and be reviewed periodically; many operators re-map on a defined cycle and additionally after any significant physical or operational change.
- Do we need monitors in every shipment?
- Not necessarily, if the shipping configuration is validated and packed to instruction. Monitoring is commonly used for higher-value or higher-risk shipments, for new routes, and to periodically verify that validated configurations still perform.
- Is ambient temperature monitoring enough?
- Ambient air temperature is what most systems measure, and it is generally what mapping and validation are based on. What matters is that the study establishes the relationship between the measured point and the product, and that the monitoring position reflects worst case.
Sources
- Guidelines of 5 November 2013 on Good Distribution Practice of medicinal products for human use 2013/C 343/01
- MHRA Guidance Note 6 — applicants and holders of a Wholesale Dealer’s Licence or Broker Registration Fifth edition 2022, section 9 amended 2023
- MHRA — Medicines: good manufacturing practice and good distribution practice