Under what circumstances is a drug considered adulterated?

A drug is considered adulterated primarily when it is produced in unsanitary conditions or contains impurities. This definition stems from the Federal Food, Drug, and Cosmetic Act, which states that a drug is adulterated if it fails to meet the established safety, purity, and quality standards. Specifically, unsanitary conditions can lead to contamination that compromises the drug's safety for consumption. Additionally, the presence of impurities can indicate that the drug may not have the intended effects or may cause harm to the patient.

The other options do not contribute to the classification of a drug as adulterated. For instance, having preservatives and being manufactured under Good Manufacturing Practices are both standard practices meant to enhance drug stability and safety, not detract from them. Similarly, being packaged in a labeled container indicates compliance with labeling laws and does not affect the drug's purity or safety status.