Which of the following is considered a common method of sterilization for injections?

Filtration is a widely accepted and common method of sterilization for injections. This technique involves passing a liquid through a filter that removes microorganisms, including bacteria and fungi, ensuring that the final solution is sterile. It is especially important in sterile compounding and the preparation of injectable medications, as it effectively eliminates contaminants without the use of heat, which could potentially degrade the active ingredients.

In contrast, boiling is not typically used for sterilizing injections due to the risk of decomposing heat-sensitive materials. Freezing and chilling are also not viable methods for sterilization, as both processes do not eliminate microbial contamination and could compromise the integrity of the pharmaceutical product, especially those intended for injection. Thus, filtration is the safest and most effective option for achieving sterilization in injectable solutions.