Final answer:
Expired drugs in a pharmacy must be quarantined until properly disposed. The disposal is managed through take-back systems in the EU or voluntary initiatives in the U.S., with incineration being the typical method.
Step-by-step explanation:
Expired drugs in a pharmacy are required to be quarantined until they can be returned or destroyed. Proper disposal of pharmaceutical waste is critical to prevent environmental pollution. In the EU, there are take-back systems to manage these residues, while in the U.S., local voluntary initiatives are more common. A significant concern is the disposal of unused or expired pharmaceuticals; if not managed correctly, they can end up in water systems. Incineration is the most common disposal method, and regulations typically dictate that chemical waste must be unused and in the form of a commercial chemical product to be acceptable for certain disposal methods.