By Angela Godwin
ATLANTA, Ga.-When Celliance Corporation, a Serologicals company headquartered in Atlanta, Ga. (www.serologicals.com), began performing environmental monitoring on their recombinant human insulin packaging suite, they immediately realized some improvements had to be made.
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Traces of the product, an extremely fine, talc-like powder used for cell culture, could be found outside the room, indicating that the dust-control mechanisms were not sufficient. In addition, the relative humidity needed to be more precisely regulated. “The powder is very hydroscopic… We had a specification for packaging which said that the humidity in the room had to be less than 40 percent, and we could meet that regularly. But we actually wanted to establish a range for the product rather than just say that it’s got to be less than 40 percent,” explains Michael Riley, technical manager for Celliance Corporation. According to Riley, if the environment is too moist, the product will absorb it; if it’s too dry, there can be static problems.
Celliance realized that in order to remedy these concerns, a new cleanroom would have to be built, one that would directly address the dust and humidity concerns. According to Riley, they wanted to build a dust control area around the workspace where the insulin product would be packaged. “We had ceiling-to-floor laminar flow as part of the general design, but we also needed lateral laminar flow across the work surface that was going to draw air across and away from the operator,” explains Riley. To address the humidity specifications, they wanted a system that would maintain a relative humidity (RH) level between 20 and 40 percent.
Celliance took their concepts to Terra Universal, a critical environment design and construction company in Anaheim, California (www.terrauniversal.com). Terra Universal worked with Celliance to provide a modular room that would meet their expectations.
The stringent RH requirements and temperature specifications proved a tricky combination. Bernie Gaon, chief engineer with Terra Universal, recalls, “The biggest challenge was being able to perform within their environmental requirements, with the outside conditions getting really extreme. Their outside conditions could get up to almost 100 percent relative humidity during the summer.”
Nevertheless, Terra Universal was able to configure a room that met the required RH and temperature controls. An air conditioning unit lowers the RH to approximately 40 percent, while a silica gel absorption system further reduces it to the target range of 25 to 35 percent.
Inside the new cleanroom, operators are in full cleanroom garb: hats, booties, jumpsuits, and gloves. And, because some people can develop allergies to these kinds of powders, full-face respirators are worn. Laser particle counters are used to monitor total particle counts, and a centrifugal air sampler monitors viable counts. Contact and settling plates are also used. III