Which of the following is NOT a criterion for a drug to be considered adulterated?

A drug is considered adulterated if it fails to meet certain standards of purity or quality as defined by law. Regarding the criteria listed:

Containing expired ingredients refers to using components that are past their expiration dates, thus compromising the safety and efficacy of the drug, making it adulterated.

Not made under acceptable manufacturing methods involves the production failing to comply with Good Manufacturing Practices (GMP). This can introduce impurities or variations in strength, which would classify the product as adulterated.

Unsafe color additives are another factor because the use of color additives that do not comply with safety standards can pose health risks to consumers, resulting in adulteration.

In contrast, the inclusion of added flavoring does not necessarily render a drug adulterated. Many pharmaceutical formulations, particularly those meant for pediatric use, incorporate flavoring agents to improve taste and patient compliance. As long as the flavoring is approved for use and does not affect the safety or efficacy of the medication, it does not meet the criteria for adulteration. Therefore, the presence of added flavoring does not compromise the drug's integrity in the same way as the other options listed.