Definition
GDP (Good Distribution Practice) is the quality management standard for the pharmaceutical distribution process. It is implemented in conjunction with GSP and focuses on the quality and traceability of drug storage, transportation, and distribution. GDP requires full-chain cold chain monitoring, temperature and humidity recording, transportation tracking, cold storage validation, transportation validation, and deviation handling to ensure the quality and safety of drugs during distribution.
GDP involves data such as cold chain monitoring, transportation tracking, and electronic supervision codes, which must meet MLPS (Multi-Level Protection Scheme), data security, and drug regulatory requirements. IoT SIM cards provide VPDN private network connections for GDP cold chain monitoring, in-vehicle temperature and humidity, transportation tracking, cold storage sensors, ensuring data security, real-time update, and completeness.
Technical Features
GDP requires temperature and humidity data collection frequency usually every 5 to 15 minutes, with real-time alerts if limits are exceeded. Transportation tracking must record start and end points, waypoints, and timestamps. Data must be retained for one year after the drug's expiration date, supporting audits and traceability. Integration with the drug supervision traceability platform allows for data reporting and regulation.
Use Cases
GDP is applied in pharmaceutical logistics, cold chain distribution, drug warehousing, and third-party logistics. Typical scenarios include cold chain transportation temperature and humidity monitoring, transportation tracking, drug traceability, temperature and humidity data reporting, cold storage monitoring, and deviation handling. SimtoLink provides VPDN private networks, dedicated APNs, real-name verification, and smart drug supervision solutions for GDP scenarios.
In-Transit Samples Must Not Be Crowded Out by Heartbeats
What the distribution rules mean for the temperature link
On an IoT SIM, good distribution practice is about whether temperature, humidity, and track during storage and transport can be kept as required, and whether a deviation is seen. The technical meaning is a sampling link. Probes in the vehicle or the insulated box take readings at a fixed interval, an out-of-limit condition sends a separate alarm at once, and the platform can hang those points on a specific waybill and drug batch. The SIM is the exit of that link. It does not verify that a drug is genuine, and it does not replace the validation report of a cold store. A heartbeat only shows that the module is still registered. It is not a temperature record.
Sample interval, limit thresholds, and how long records are kept are set in the quality file. The communication design has to follow those intervals, not the other way around, with a plan tier deciding that a report is allowed only every few minutes. How a temperature counts as a deviation can be read against temperature deviation. The distribution step also has to keep the start, the end, and the handovers of the shipment. A temperature curve alone does not say which batch of drug it was.
Conditions before a refrigerated vehicle is activated
The probes are calibrated, the logger keeps sampling after power is lost, and the SIM's access point can reach the quality platform rather than an arbitrary public address. Each refrigerated vehicle, insulated box, and temporary third-party truck needs its own SIM bound to a plate or a box number. Cross-region routes must confirm roaming or coverage. Tunnels and unloading docks may cache, and after a blind spot the out-of-limit alarm goes first, then the ordinary samples. Size the plan for the whole trip's samples plus alarms. One quiet hour in the garage is not the in-transit volume.
If quality rules require data to be kept until an agreed time after expiry, both the platform store and the onboard store have to meet that. Do not rely only on "the SIM already uploaded it." When the carrier changes, the SIM may change. The batch and waybill numbering must not change algorithm. Whether the pre-cool before departure is part of the record has to be written in the rules, so a hot segment in the garage is not counted as a transport deviation, and the transport segment is not left out.
An out-of-limit alarm that arrives after unloading
A common failure puts the alarm and the periodic samples in the same low-priority queue. The cargo is already over temperature, heartbeats and normal points are still going out, and the alarm waits until after unloading. Another uses the time the network returned, inside a blind spot, as the sample time, so the deviation window shifts and the investigation cannot find the stretch that was actually hot. If the SIM is suspended for a device-SIM split, the logger still has local data, but nobody exports it at handover. The link shows a blank, and later that is treated as "there was no monitoring."
When several probes share one SIM and the message has no probe id, cab temperature and cargo temperature become one line. Acceptance should create one short out-of-limit event while driving, confirm the alarm arrives before the later normal points, and confirm that the time after a blind-spot backfill is still the time the limit was crossed.
Departure and arrival handovers have to line up with the temperature curve, or nobody can tell whether the limit was crossed in transit or on the dock. Opening the door at the dock often raises the temperature. If the rule counts the whole trip, a normal load or unload is recorded as a deviation. If the rule excludes loading and unloading, there must be a door-open event. The curve must not be altered by hand afterwards. Door open, door close, departure, and arrival should all be timed events, on the same clock as the temperature points. Probe placement belongs in the record. A probe on the air outlet and a probe among the goods do not read the same. Moving it without updating the note looks like an equipment fault. A probe past its calibration date should not keep uploading as valid data. At least carry a calibration-status field so quality staff can filter it out. Suspending the SIM must not delete records still on the vehicle that have not been exported. The handover list should say "local points still unsent," so the driver does not clear the logger by cutting power.