Editorial: Vapour hydrogen peroxide - a sterilising agent?

摘要

It is an unusual step for an inspector to step up and write a blog to make a point that he felt that people were just not getting. This blog is most likely a result of responses to the recently released new version of Annex 1. On 20 April 2018, Andrew Hopkins (Senior Medicines and Healthcare Products Regulatory Agency (MHRA) Inspector) wrote an MHRA blog1 giving a clear MHRA interpretation of the use of vapour hydrogen peroxide (VHP). The clarity was that currently VHP is a decontamination agent not a sterilising agent. With all Grade A microbiology results, the requirement is no viable organisms isolated2. What this means in practice, is that you can possibly accept >1 colony-forming unit/test within a scientific justification. This is not the case for sterility test failures. For VHP, there is a requirement to show that the decontamination works but not a requirement to show a 6-log reduction - although this is the current practice during initial and periodic validation. Isolators and restricted access barrier systems (RABS) are small cleanrooms that typically integrate process equipment as part of the barrier. There is no requirement for barrier surfaces or non-product contacting surfaces of process equipment within to be sterile. Sterility assurance is gained both by using a recognised sterilisation process and validating this by a 6-log reduction of an accepted indicator species. It is not the other way around. You cannot claim a sterilisation process by having a 6-log reduction and claiming that therefore the "kill" process is a sterilising process. The blog focuses on considerations in fragility of VHP relative to failure to inactivate spores in clumps (as sometimes found on biological indicators) and where bio-contamination is protected from the sporicidal process, e.g. fatty acids from human contact. It follows qualifying a VHP process with clean un-clumped spores, as is often the case, does not assure surfaces are actually sterile if bioburden has characteristics that do not support biological inactivation.