Q345 · What is a “Retention Sample”? Do…

Q345 · Category G: Quality management and compliance systems (Q301–Q350)

A retention sample is a representative sample taken and kept from each batch of medicines. Its main purpose is to ensure that, in the event of a product quality complaint, suspected counterfeit medicines or an investigation, an original-condition sample identical to the distributed product is available for examination and testing. Under GMP, medicine manufacturers must retain sufficient samples of every batch released from the factory. Hong Kong GDP regulations do not require pharmaceutical wholesalers to retain samples of all products. However, in certain circumstances—for example, where a wholesaler has carried out an operation that may affect the integrity of product packaging (such as relabelling), or where required under a quality agreement with the manufacturer—the wholesaler may also need to retain samples.

📘 Regulatory basis

The PIC/S GMP Guide sets out clear and detailed requirements for manufacturers to retain samples. Hong Kong's GDP guidelines do not impose the same requirement on wholesalers, placing this responsibility mainly on manufacturers.

📗 Drew Tang's recommendations

Although this is not a statutory requirement, we recommend that wholesalers clearly allocate responsibility for retaining samples and specify how to obtain them in quality agreements with their main suppliers. You need to ensure that, when necessary, you can quickly obtain a retained sample of a particular batch from the manufacturer to support an investigation. For products that you have repackaged, for example, we strongly recommend retaining samples yourself, as you determine the product’s final state.

📕 Risk notice

If neither the manufacturer nor your company has retained a sample when handling a quality complaint, the investigation will be at a serious disadvantage. You will lack the most direct physical evidence for assessing whether the complaint is genuine or identifying the root cause. While this does not in itself constitute a breach by the wholesaler, it will significantly undermine your ability to handle quality incidents.

Plan Your Hong Kong Pharmaceutical Licensing Project with Drew Tang

Business Manager Tang Shangyong (Drew Tang) will review your products, operating model, licence type and preparation requirements with you one-to-one. The precise service scope is confirmed in writing; pharmaceutical duties are carried out by legally qualified personnel, and approvals are determined by the competent authorities.

What is a “Retention Sample”? Do pharmaceutical wholesalers need to keep one?

Plan Your Hong Kong Pharmaceutical Licensing Project with Drew Tang