by Hank Rahe
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Containing potent compounds is becoming even more of a challenge for the pharmaceutical industry. As new drugs are more focused in terms of specific receptor sites in the human body, smaller quantities of the compound will effect those individuals who are exposed. Many compounds that are currently in development are found to have exposure limits in the low nanogram range.
While the shift to lower drug dosages is wonderful for the patient, it creates the need for a shift in paradigm for individuals working in the research and development laboratories. The old thought was, “a little bit of material is not dangerous,” and many operations were carried out on open bench tops or in unidirectional air flow environments. If this open handling of materials is continued, it creates risks, not only for the individual handling the material, but for others working in the same facility. In many cases these materials are newly created and the long-term effects are not fully understood.
Using tracer materials, tests have shown that materials are primarily tracked by the hands and the feet. During one test, materials handled with “normal” precautions were found on telephones, door handles, hallways outside the laboratory space, water fountains and in the restroom. The large areas of the building contaminated by the tracer material indicates that the individual handling the materials and others run the risk of exposure.
While containment at the source is important, it has met with resistance. Initial efforts by the manufacturers of the containment devices had not considered the degree of freedom required by individuals working in the laboratories. Poor ergonomic design, coupled with the lack of understanding of the activities being performed, has lead to containment devices that are used improperly or not used at all.
An example is a balance placed in a containment device using unidirectional air flow. The physical environment must be such that the air flow does not disturb the accuracy of the balance and any vibration from the blower is eliminated. Consideration must be given as to how the laboratory personnel will interact with the balance, in terms of placing materials on the balance and how they will recover or dispose of the materials when the operation is complete.
The inability of the enclosure to satisfy these needs will result in improper use of the device. The devices will be turned off or changed to remove the functional problem leaving an even more dangerous situation.
Developing enclosures to satisfy the needs of the laboratory or development operation starts with an understanding of the unit operations taking place. The laboratory is no different than production operations in that a defined number of activities can be established requiring the interaction of personnel and equipment. Each, in turn, needs to be evaluated regarding the requirements of the equipment and the need for personnel to interact. The enclosure used to separate the activity from the laboratory or development space must meet all these needs or it will not be used properly, negating the protection it provides.
The containment system must have at least two levels of protection. The first, a physical structure that has integrity and the second, the proper pressurization scheme. The integrity of the physical structure includes the ability of individuals to interact and materials to enter and leave safely. If the structure contains a piece of equipment with moving parts, safeties need to be in place to prevent personnel from reaching into a dangerous area while the equipment is operating.
Research and development facilities require a greater level of containment because more potent compounds are being developed. If containment is to be successful, individually designed enclosures will be required rather than the initial approach of simply putting the activity 'in a box.'
Hank Rahe is director of technology at Contain-Tech in Indianapolis. He is the past chairman of the board of the International Society of Pharmaceutical Engineers, and is on the CleanRooms Editorial Advisory Board.