Which of the following defines a medium risk CSP?

A medium risk compounded sterile preparation (CSP) is defined by the complexity of the preparation process and the potential for contamination. When using multiple doses from a single vial, there is an increased risk of contamination due to the handling and potentially extended time before the product is used. This makes it a characteristic of medium risk CSPs, as the preparation involves more than just the mixing of sterile ingredients and requires greater attention to maintaining sterility throughout the process.

In contrast, other options do not appropriately define a medium risk CSP. Using only 1-3 sterile ingredients is more characteristic of low-risk compounding, where the assembly involves fewer variables and less potential for contamination. A requirement for a sterile environment is essential for all CSPs, not just medium risk, and thus does not uniquely define them. Finally, containing only nonsterile ingredients applies to formulations that need additional sterilization before use, which is not relevant to the definition of medium risk CSPs. Understanding these definitions helps reinforce the importance of sterility and the complexity associated with CSPs in a pharmacy setting.