Expiry once Opened

Once a sterile aqueous solution is accessed for the first time, it is no longer in a fully sealed, sterile environment. Although these formulations contain a preservative system designed to limit microbial growth, regulatory standards and preservative-effectiveness testing only validate this protection for up to 28–30 days after initial puncture.

This time frame is based on well-established industry and laboratory findings showing that, after repeated access, the likelihood of introducing environmental microorganisms increases. Preservatives slow or inhibit microbial proliferation but do not sterilise the solution. Over time, and with cumulative exposure events, the ability of the preservative to reliably suppress potential contaminants can no longer be assured.

For this reason, international quality and safety standards—such as USP Antimicrobial Effectiveness Testing (Chapter <51>) and USP Sterility Tests (Chapter <71>)—set clear limits on how long multi-use sterile solutions may remain suitable for continued use after a container is breached. These limits are also reflected in guidance from global regulatory agencies, which cap the allowable in-use period unless extended stability and preservative-effectiveness data are provided.

In practical terms, the solution itself does not “expire” immediately after 30 days, but beyond this period the manufacturer and governing standards can no longer guarantee the same level of microbial protection. This is why all sterile aqueous solutions with preservatives are labelled with a maximum 30-day window after initial access.

Adhering to this guideline ensures that the integrity and reliability of the solution remain consistent throughout its intended in-use period. For storage-specific instructions, please refer to the individual product page.