What is the recommended expiration period for a multi-dose vial after it has been opened?

The recommended expiration period for a multi-dose vial after it has been opened is 28 days. This guideline is based on the stability and sterility of the contents once the vial is first accessed. After opening, multi-dose vials are susceptible to contamination and degradation from exposure to air and handling, which is why it's important to have a defined period for safe usage.

Choosing 28 days as the expiration period balances the need to prevent waste of usable medicine while ensuring patient safety. It allows healthcare providers sufficient time to utilize the remaining doses without exceeding the safe usage window where the efficacy and safety of the medication can be guaranteed. This standard is commonly referenced in clinical practice to ensure adherence to best practices for medication handling.