Final answer:
An institutional pharmacy is considered closed when it is not during its regular business hours or when there is no licensed pharmacist present to supervise operations.
Step-by-step explanation:
An institutional pharmacy is considered closed when it is not open during its posted or regular business hours, or when a licensed pharmacist is not present and available to supervise pharmacy operations and to respond to patient's medication-related needs. In many jurisdictions, regulations stipulate that an institutional pharmacy must have a pharmacist on-duty during operating hours to ensure patient safety and compliance with legal requirements.
The absence of a licensed pharmacist typically requires the pharmacy to restrict access to medications. In hospitals or other medical facilities, this might mean that an automated system, such as a Pyxis machine or another electronic medication dispensing system, is used to control access to medication when the pharmacy is closed, which would be managed and restocked by pharmacy staff during open hours.