Test and reference items are the substances being evaluated and the comparators used in a GLP-compliant study, respectively. The OECD GLP Principles require that all test and reference items be properly identified, characterized, handled, stored, and documented throughout the study lifecycle. Proper management of these items is critical to study validity and regulatory acceptance of results.

Characterization and Identification

Each test and reference item must be characterized with information including its identity, purity, composition, stability, solubility, and expiration date. A unique identification code must be assigned and tracked throughout the study. Certificates of analysis from suppliers or internal testing provide the necessary characterization data.

Receipt and Storage

Upon receipt, test and reference items must be inspected for damage, logged into the inventory system, and stored under conditions specified by the manufacturer or study plan. Storage conditions such as temperature, humidity, and light exposure must be monitored and documented. Segregation of test items from other materials prevents cross-contamination and mix-ups.

Handling and Preparation

Procedures for handling, diluting, mixing, and administering test and reference items must be defined in Standard Operating Procedures (SOPs) or the study plan. Homogeneity and stability of formulations must be confirmed, particularly for studies involving repeated dosing over extended periods. All handling activities are documented in contemporaneous records.

Chain of Custody

A complete chain of custody must be maintained from receipt through use and final disposition, documenting each transfer, usage, and return. Disposal of test and reference items must follow applicable environmental and safety regulations, with disposal records retained in the study file. Any discrepancies in inventory must be investigated and resolved.

Conclusion

Rigorous management of test and reference items is essential for study integrity and regulatory compliance. Proper characterization, storage, tracking, and documentation ensure that study results can be attributed to the correct substance and reproduced if necessary. Facilities must establish robust systems for item management as part of their overall GLP quality framework.