Which of the following changes to a drug product is MOST likely to be implemented without prior regulatory authority approval?

The option relating to strengthening a precaution to the product labeling is the most likely change that can be implemented without prior regulatory authority approval. This type of modification is typically considered a routine update that reflects new safety information or enhances clarity, which is crucial for ensuring patient safety. Regulatory agencies often allow manufacturers to make such adjustments to labeling to better inform users about risks and contraindications without the need for a formal submission.

In contrast, adding a new active ingredient is a significant change that could alter the efficacy and safety profile of the drug, thereby requiring thorough review and approval from regulatory authorities. Changing the product’s color may seem minor, but it can have implications for branding, consumer recognition, and possibly even safety (e.g., in the case of differentiating products), thus often necessitating prior approval. Modifying the dosage form, such as altering from a tablet to a liquid form, changes how the medication is administered and absorbed, which also demands regulatory evaluation.

Therefore, strengthening a precaution in the labeling stands out as a proactive approach to safety that manufacturers can take immediately without seeking approval, in alignment with the principles of risk management and post-market surveillance.