Validation of a Sporicidal Bio-Decontamination Process for use in Pharmaceutical Isolators in an NHS Aseptic Manufacturing Unit

Abstract

The recently published revision of EU GMP Annex 1 Manufacture of Sterile Medicinal Products includes a requirement for pharmaceutical isolators to undergo a bio-decontamination process of the interior which should be automated, validated and controlled within defined cycle parameters and include a sporicidal agent. It is widely accepted that the easiest way to achieve this is by converting Hydrogen Peroxide (H2O2) liquid into a state that will diffuse readily through the closed isolator chamber leading to bio-decontamination of all surfaces which it comes into contact with. The technology to do this has been around for years and can be validated to give a high level of assurance of surface bio-decontamination comparable with sterilization when used on surfaces in the isolator critical work zone. This type of activity is routinely used in large-scale sterile manufacturing that takes place in the pharmaceutical industry where the amount of materials and timescales involved make this viable. In the NHS, aseptic preparation and manufacture of sterile products is carried out in isolators both for immediate use and for stock in anticipation of demand. Automated bio-decontamination systems are available but their use is much less than in the pharmaceutical industry and reliance is still placed on manual spraying and wiping of surfaces with disinfectant agents such as alcohol and hydrogen peroxide. This brings a degree of variability and is more difficult to validate. For sterile manufacturing units holding an MHRA Specials Manufacturing licence the expectation is that proper consideration is given to using an automated bio-decontamination process or there is justification for not doing it. For units preparing products for immediate use there is not the same expectation but as standards are improved, it is reasonable to assume it may become the case in the future. To use this type of process requires it to be integrated into the isolator, meaning either buying a new isolator or retrofitting to an existing one. The relatively high cost of this is a barrier to pharmacy department aseptic units using the technology. There is a range of bio-decontamination systems on the market from Devea (www.devea environnement.com)which are claimed to be suitable for use in hospital pharmacy clean room facilities. One model from this range, the Phileas Genius is a simple, stand-alone battery powered unit that generates vapourized hydrogen peroxide of particle size 5-10 µm from 7.4% solution using novel spinning disc technology. This generator can be transferred into and out of any closed isolator work zone through the transfer hatch (as long as the hatch door is wide enough) and can be used to do pre-programmed cycles (called zones) to routinely decontaminate inner surfaces.