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.