Which of the following tests can confirm the sterility of a compounded preparation?

Endotoxin testing is a critical method for confirming the sterility of a compounded preparation. This test specifically detects the presence of endotoxins, which are toxic substances that can be released from the cell walls of Gram-negative bacteria. While the absence of these toxins indicates that no bacterial contamination has occurred during the compounding process, it also provides valuable insight into the overall sterility of the product.

Endotoxin testing is typically performed using techniques such as the Limulus Amebocyte Lysate (LAL) test, which utilizes the blood of horseshoe crabs to indicate the presence of endotoxins. This is particularly important in sterile compounding, as any presence of endotoxins can lead to serious adverse reactions in patients receiving the compounded medications, especially those with compromised immune systems.

In contrast, the other testing methods mentioned, such as pH testing, solubility testing, and colorimetric analysis, focus on different aspects of the preparation and do not directly confirm the sterility of a product. pH testing assesses the acidity or basicity of a solution, which is crucial for the stability of certain compounds but does not indicate microbial contamination. Solubility testing evaluates whether a substance can dissolve in a particular solvent, while color