Final answer:
It is generally not acceptable to combine return-to-stock vials with stock bottles in a pharmacy due to risks of contamination and drug potency issues.
Step-by-step explanation:
In response to the question regarding the Annual Physical Inventory and the practice of combining the contents of a return-to-stock (RTS) vial with a stock bottle of the same medication, it's important to apply strict protocols. Generally, it is not acceptable to combine RTS vials with stock bottles due to potential contamination, inconsistency in drug potency, and variations in expiration dates. The integrity of the medication must be maintained to ensure patient safety. Therefore, all handling should adhere to pharmaceutical guidelines, which often dictate that returned medications should not be re-dispensed or mixed with other stock due to the risk of cross-contamination and the difficulty in tracking the medication's history once it has left the pharmacy's control.