The meaning of cleaning
04/01/2000
by Hank Rahe
Cleaning takes on a whole new meaning in the area of life sciences where the objective in cleaning is to remove potential cross contamination, defined as anything that is not an ingredient in the product.
In the different segments of the industry, 'cleaning' can mean very different things. For example, the sanitizing step in the manipulation of parenteral products many times is called 'cleaning.' cGMP cleaning in the life sciences is defined by our ability to measure for the presence of any material. The ability to detect or measure for any cross contamination, especially the active ingredient, is important as products are becoming more potent. The potent compound active ingredients are effective in extremely small quantities. This means that a small amount of cross contamination can create an adverse effect.
Many potent compound processing steps take place in closed systems, making the cleaning process difficult to achieve when the goal is a non-detect level. Cleaning of the facilities that process potent compounds should be divided into two steps. The first step is deactivation or removal of the potent material to the level at which effective cGMP cleaning can take place. This is important, because many times the cleaning required to achieve the cGMP level requires a brisk physical intervention.
There should be a defined approach to the first level of preparing the facility or equipment for cGMP cleaning. In most cases, the product is a powder and has contaminated the area by becoming airborne during the process. After the powder has settled onto a surface, it is important to capture it on the surface without allowing it to become airborne again during the attempt to remove it. Lightly misting the surfaces with liquid is an effective means of capturing the powder on the surface. A typical "washing" will cause the materials to break free of the surface and become airborne. These particles will resettle contaminating the same or other surfaces after the washing.
Misting is the preferred method versus wiping of surfaces, because it creates a more uniform coverage of the surfaces resulting in a more complete capture of the particles. After the particles have been captured by the wetting mist, they can then be rinsed away with less risk of becoming airborne. The "firehose" approach to cleaning needs to be tempered until the final cGMP cleaning takes place.
In the first step in the cleaning process the goal is to reduce the level of active product below its exposure limit so the final cleaning steps may take place. In most cases, the initial step takes place while the system is closed. Personal protective equipment may be necessary in the final cGMP cleaning and is a function of several factors.
The factors to consider when making the decision to use personal protective equipment during cleaning are the ability to view the process environment, the impact of an exposure, and the level of validation of the initial deactivation step. In all cases personal protective equipment should be worn during the validation of the deactivation steps. The ability to see the process area is important to verify that the misting and rinse was effective. The impact of the exposure to the product on personnel will determine an acceptable exposure risk factor and the validation level will determine the effectiveness and reliability of the deactivation process.
cGMP cleaning requires a validated process for the removal of any potential contaminant from surfaces. Potent compounds have complicated the cleaning process by adding to the equation the requirement to protect personnel during the cleaning.
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Hank Rahe is director of technology at Contain-Tech in Indianapolis. He has over 30 years' experience in the healthcare industry, as well as four years in academia. He is an expert in the areas of conventional and advanced aseptic processing. He is the past chairman of the board of the International Society of Pharmaceutical Engineers, and is a member of the CleanRooms Editorial Advisory Board.