As a manufacturer of generic and branded drugs using proprietary drug delivery systems such as time-release and site-release processes, St. Louis-based KV Pharmaceutical Co. is subject to plenty of federal regulation.

“Being in a regulated industry, we’re required to do environmental monitoring for temperature, relative humidity and that kind of thing. We’re required to monitor those things and record them, so that we can present those data to the FDA (Food and Drug Administration) if requested,” notes Chip Bennett, validation specialist at the company.

For KV Pharmaceutical, this once meant the need for hundreds of permanent chart recorders wired to sensors throughout the company’s multiple
St. Louis

Today, though, that is rapidly changing, as the company converts to mesh network-based wireless systems—both for revalidation and for permanent environmental monitoring. The wireless systems, supplied by GE Sensing, a Billerica, Mass.-based division of General Electric Co., rely on wireless mesh technology from Dust Networks Inc., based in
Hayward, Calif., and from Sensicast Systems Inc., based in Needham, Mass.

Labor intensive

The traditional monitoring method based on chart recorders has various drawbacks, says Bennett. One of the largest is that maintenance is labor intensive. “You have personnel constantly going around to maintain the chart recorders and replace recorder papers weekly,” he notes, “and when you’ve got hundreds of monitoring locations spread over several locations that may be miles apart, as we have here, that only compounds the problem.”

To avoid these issues, KV Pharmaceutical began replacing its chart recorders with  GE Sensing’s Kaye LabWatch systems, which use sensors with integrated input/output hardware that are networked for alarming, data acquisition and storage, viewing and reporting from a central location. These initial systems relied on wires to connect the sensors. But around mid-year 2005, KV Pharmaceutical began making the switch to the wireless version of the LabWatch system, says Bennett.

With the 2.4 Gigahertz wireless LabWatch system, which uses self-organizing mesh network technology based on the
Institute of
Electrical and Electronics Engineers’ IEEE 802.15.4 standard, “it’s much easier to locate sensors wherever you need them,” Bennett observes. “It’s much easier to maintain because you don’t have to worry about a wiring system, and it’s a whole lot more scalable.”

The wireless LabWatch systems work primarily with temperature and/or relative humidity sensors at KV Pharmaceutical, depending on the application. Current sensor locations include processing areas, manufacturing rooms, packaging areas, drying ovens, stability chambers, incubators and cold storage areas.

“We currently have LabWatch systems installed in five facilities,” says Bennett; this encompasses a total of about 200 wireless monitoring points. A sixth location is currently being added, and Bennett plans to request funding next year to add wireless LabWatch systems at the company’s two remaining primary manufacturing facilities.  

The LabWatch systems monitor environmental conditions continuously. In most cases, only one sensor is mounted within a room or area, in a spot that is deemed to the be the “worst-case” location for variability of the parameter being monitored, Bennett says. Determining that “worst-case” location is done during periodic required revalidation tests through temperature mapping, which is done using another system provided by GE Sensing.  

“Generating temperature map data is a requirement for validation [and revalidation] of a facility, a process or a stability chamber—demonstrating the temperature change across the entire volume,” Bennett notes. The traditional way of doing this, he says, is to string up typically 15 or 27 wired thermocouples in a given area, where they are used to gather temperatures for a designated time period—in some cases, up to 30 days. The thermocouples are arranged in a three-plane grid with either five or nine monitoring points to create the “temperature map,” Bennett explains. Each sensor wire—up to 30 feet in length—is linked back to a central data collection unit such as GE Sensing’s Kaye Validator 2000.

When the study is complete, the temperature map data can be used to prove that air handling systems ...