Which auxiliary label must always be applied to suspension medications?

The requirement to apply the label "Caution: Shake well before use" to suspension medications is essential because suspensions are liquid formulations in which solid particles are dispersed throughout the liquid phase. Over time, these solid particles can settle at the bottom, leading to the medication not being distributed consistently. By shaking the suspension before use, the pharmacist ensures that the active ingredients are properly mixed and that the patient receives the correct dosage upon administration.

This label serves an important role in medication safety and efficacy, as it reminds patients of the necessary action to prepare the medication correctly. Providing clear instructions enhances patient adherence to the prescribed treatment and minimizes the risk of administering an ineffective dose.

In contrast, while other labels may also have safety or storage implications, they do not specifically address the critical need for uniformity in suspension medications. "Keep away from children" provides a safety warning, but it is not unique to suspensions. "Store in a cool place" pertains to storage conditions but does not specify handling instructions at the time of use. "Take with food" refers to the timing of the dose in relation to meals and is not relevant to the nature of the suspension itself. Hence, the requirement for the label ensuring proper mixing is paramount for suspensions.