What is the purpose of a cotton ball in drug preparation?

The purpose of a cotton ball in drug preparation is primarily to filter impurities. In various pharmaceutical processes, cotton balls are used as a simple and effective means to filter out solid particles, dust, or other contaminants from a solution. When a drug solution is being prepared—such as when creating syringes or preparing intravenous medications—the cotton acts as a barrier that ensures only the desired, clean liquid passes through while trapping any unwanted materials.

Using a cotton ball in this way enhances the purity of the medication being administered, thereby helping to ensure patient safety and the effectiveness of the drug. It's particularly useful in settings where sterility and cleanliness are paramount, as it can help prevent infections and reactions that could occur if impurities were introduced into the therapeutic regimen.

The other options provided are not relevant to the primary function of the cotton ball. For instance, while cotton can have absorbent properties, its main role in drug preparation is not to absorb excess liquid or dissolve drugs. Similarly, flavoring agents are typically not part of the filtration process, but rather are considered separately based on the type of medication being formulated.