GDP (Good Distribution Practice, İyi Dağıtım Uygulamaları) is the set of rules that ensures the quality, temperature conditions and traceability of medicinal products for human use are maintained while they are stored and transported from the manufacturer to the pharmacy. In the EU it is defined by guideline 2013/C 343/01; in Türkiye, pharmaceutical warehouses operate according to these principles under the supervision of the Turkish Medicines and Medical Devices Agency (TİTCK).
What does GDP cover?
The European Commission guideline of 5 November 2013 consists of eleven chapters. The first ten chapters regulate the following topics:
- Quality management and control of outsourced activities,
- Personnel, in particular the responsible person; a pharmacy qualification is preferred,
- Premises and equipment: temperature mapping, calibration, qualification and validation,
- Documentation and records,
- Operations: qualification of suppliers and customers, receipt, storage, destruction, dispatch,
- Complaints, returns, suspected falsified products and recalls,
- Outsourcing contracts, self-inspection, transport and brokers.
A separate GDP guideline for active substances was published in 2015. The World Health Organization also defines good storage and distribution practices for countries outside the EU in TRS 1025 Annex 7.
Why does it matter?
The quality of a medicine can deteriorate even after it leaves the factory. A vaccine that must be stored at 2–8 °C may lose its efficacy if it stays below freezing for a few hours, and this damage is invisible. GDP requires proof, through records, that the product's conditions were maintained throughout the journey. The transport chapter of the guideline states this clearly: whatever the mode of transport, it must be possible to demonstrate that the product has not been exposed to conditions that could compromise its quality. Preventing falsified medicines from entering the legal supply chain is another aim of the same rules.
How is temperature control ensured?
| Storage condition | Typical product |
|---|---|
| +2 / +8 °C (chilled) | Vaccines, insulin, many biological products |
| +15 / +25 °C (controlled room temperature) | Most tablets, capsules and syrups |
| −20 °C and below (frozen) | Some biological and investigational products |
- Before use, the warehouse undergoes temperature mapping under representative conditions; monitoring devices are placed at the points where the extreme values occur.
- In refrigerated vehicles, mapping takes seasonal variations into account.
- Monitoring devices in vehicles and containers are calibrated at regular intervals, at least once a year; a temperature data logger record is kept throughout the journey.
- In thermal boxes, cool packs do not come into direct contact with the product; frozen and chilled packs are kept separate.
- Any deviation is reported to the distributor and the recipient and investigated according to a written procedure.
Practice on the road is explained in detail in cold chain road transport.
How are validation and traceability managed?
Which equipment requires qualification and which process requires validation is decided through a documented risk assessment. Computerised systems are validated before use. Records are kept for the period set by national legislation, at least five years. A wholesale distributor buys only from authorised suppliers and sells only to authorised recipients. In Türkiye, the QR code on medicine packs records every change of hands in the chain via the Pharmaceutical Track and Trace System (İlaç Takip Sistemi).
Who is it mandatory for?
| Party | Relationship to GDP |
|---|---|
| Pharmaceutical warehouse, wholesale distributor | Legal requirement; wholesale distribution authorisation in the EU, TİTCK authorisation and inspection in Türkiye |
| Pharmaceutical exporter | Under the EU guideline, export also counts as wholesale distribution |
| Carrier and 3PL warehouse | No direct licence; a written contract with the distributor and openness to audit are required, and in practice a GDP certificate is requested |
| Broker | Registration mandatory; does not physically handle products |
The certification process for carriers is explained in how to obtain a GDP certificate.
How does Voltim Global support this?
Voltim Global carries out pharmaceutical and temperature-sensitive shipments that require GDP together with partners holding a GDP certificate. In cold chain logistics shipments, temperature records, deviation reports and delivery documents are kept within this framework.