Drug accountability encompasses the comprehensive tracking of investigational product from receipt at the investigational site through final disposition, creating an unbroken chain of documentation that demonstrates what happened to every unit of study medication. This meticulous accounting serves multiple purposes: verifying that participants received assigned treatments as intended, confirming that no product was diverted or misused, supporting assessment of participant compliance, and demonstrating that proper storage and handling procedures were followed throughout.

The drug accountability record documents the complete lifecycle of each medication unit at the site. Receipt records capture shipment details, quantities received, lot numbers, expiration dates, and confirmation that products arrived in acceptable condition. Dispensing records link specific medication units to specific participants and visits, documenting what was provided and when. Return records capture products brought back by participants, enabling calculation of compliance based on remaining medication. Destruction or return-to-depot records document final disposition of unused product.

Accountability reconciliation must demonstrate that all product is accounted for throughout the trial. The fundamental equation requires that quantity received equals quantity dispensed plus quantity remaining plus quantity destroyed or returned, with any discrepancies fully investigated and documented. Monitors verify accountability records during site visits, comparing physical inventory against documented counts and reviewing the chain of documentation for completeness and accuracy. Unresolved accountability discrepancies may indicate serious compliance issues requiring investigation.