What criterion must be met for a drug to be returned and repackaged?

The correct criterion for a drug to be returned and repackaged is that the drug must be in an unopened tamper-evident unit. This requirement ensures the safety and integrity of the medication. When a drug is in an unopened and tamper-evident container, it indicates that the product has not been exposed to contamination or deterioration. Tamper-evident packaging is designed to show whether the product has been altered, ensuring that consumers and healthcare providers can trust that the drug remains safe for use.

Returning and repackaging drugs in any other condition, such as an opened container, would raise significant safety concerns about contamination and product integrity. Moreover, the repackaging process should be performed with proper handling to prevent any risk of reintroducing contaminants. Therefore, adherence to the criterion of an unopened tamper-evident unit is crucial in maintaining drug safety during return and repackaging processes.