Good Distribution Practice (GDP): What It Requires
A pallet of medical products leaves a manufacturer's warehouse in full compliance with every production standard that applies to it, and everything that happens to that pallet afterward — how it is stored, how it is trucked, who handles it, how long it sits on a loading dock — falls outside the manufacturer's control and inside a different framework entirely. Good Distribution Practice (GDP) is the set of requirements that governs that afterward: the storage and transport chain between a manufacturer's gate and the point of use. It is easy for a buyer to assume that a product's quality is fixed once it passes manufacturing; GDP exists because that assumption is wrong.
GDP Is a Different Question From GMP
Good Manufacturing Practice (GMP) asks whether a product was made correctly. GDP asks whether a correctly made product was kept correct on the way to the customer. A distributor, freight forwarder or warehouse operator that never manufactures anything can still be the point where a product's integrity is lost — through a temperature excursion, a damaged package, or stock that sat past its usable window without anyone noticing. GDP treats storage and transport as quality-relevant steps in their own right, not as neutral logistics that happen after quality has already been decided.
Storage: Conditions, Monitoring and Segregation
A GDP-run warehouse typically maintains temperature and humidity mapping across its storage areas, since a single reading at the door does not represent what a pallet in a far corner actually experiences. Calibrated monitoring equipment with an audit trail, rather than a single thermometer checked occasionally, is the baseline expectation. Physical segregation matters just as much as temperature: quarantined, rejected, expired and recalled stock needs to be kept clearly separate from saleable inventory so that nothing moves out the door by mistake. Stock rotation should follow a first-expiry-first-out (FEFO) logic rather than simple arrival order, since the goal is to move product before it expires, not before it arrives.
Transport: Maintaining the Chain of Custody
Storage conditions mean little if they are not preserved in transit. GDP calls for transport routes and packaging to be validated for the conditions a shipment will actually encounter — a cold-chain product needs qualified insulated packaging and, for longer or higher-risk routes, active temperature monitoring rather than an assumption that the trip is short enough not to matter. Any temperature excursion during transport should be a documented, investigated event, not something quietly ignored because the product arrived looking fine. Where a subcontracted carrier is used, the distributor holding the product's quality obligation still needs oversight of that carrier's practices — outsourcing the truck does not outsource the responsibility.
Documentation and Traceability
A defining feature of a GDP system is that a shipment's history can be reconstructed after the fact. That typically means being able to answer, for any given lot: where it was stored, at what conditions, who handled it, when it moved, and to whom it was delivered. This traceability is what makes a recall workable — a distributor that cannot say which customers received a specific lot cannot execute a recall efficiently, regardless of how well the recall itself is planned.
Quality System and the Responsible Person
GDP is usually implemented as part of a broader quality management system, with a designated person accountable for compliance, defined procedures for handling deviations and complaints, and periodic self-inspection to catch drift before an external audit does. A system that exists only on paper — procedures nobody follows day to day — provides none of the actual protection GDP is meant to deliver.
The Takeaway
GDP is the recognition that a product's quality is not locked in at the factory gate; it depends on every storage and transport step afterward being controlled and documented as carefully as the manufacturing step was. For a buyer, asking a supplier how its GDP system actually works — not whether it exists — is a reasonable and useful due-diligence question.
This is general educational information, not legal or regulatory advice; consult the current official texts and your competent authority.
