MedImmune Integrates Control of Cold-Chain Distribution Center
Vaccines are one of the pharmaceutical industry’s most perishable products. The shelf-life of biologic agents, such as influenza vaccines, is relatively short even under ideal conditions – around six months. Most of these life-saving agents are sensitive to temperature variations. Any break in the “cold chain” could harm their potency and effectiveness in warding off disease.
MedImmune – the global biologics research and development arm of pharmaceutical giant AstraZeneca – operates its single cold-chain distribution facility near Louisville, Kentucky. From there, it annually ships millions of doses of FluMist®, the first nasal-spray flu vaccine approved by the U.S. Food and Drug Administration (FDA).
The Louisville distribution center is strategically located near major facilities for commercial shipping companies that deliver the vaccine to hospitals, clinics and retail pharmacies. One of MedImmune’s major customers is the U.S. Department of Defense, which contracts with the company to provide the flu-shot alternative to American military personnel based around the world.
The distribution center stores the FluMist pallets in two FDA-validated, temperature-controlled freezer spaces, totaling 27,000 square feet. Each frozen space also contains automated storage-and-retrieval systems that include conveyors, lift tables and robotic cranes, which break down the pallets and cases. A high-tech, pick-and¬-pack area is equipped with eight stations where orders are filled in various quantities for various customers.
A large percentage of orders are small parcels delivered in one or two days. They’re shipped in passively-cooled containers – essentially, ice chests containing frozen gel packs to maintain the cold chain until the products reach their destinations.
The distribution center facility contained diverse legacy systems, partly because it changed ownership twice before AstraZeneca bought it in 2007. In addition, the automation systems were largely siloed. For example, each freezer’s ammonia-based refrigeration system operated independently.
“We had eight separate control systems that were loosely connected at best,” explained Jim Heckmanski, senior manager for global automation at AstraZeneca’s Global Operations/Supply Biologics division. “The components that were networked were on our public business systems, so when IT would do maintenance on the corporate network, we were subject to interference.”
The lack of a dedicated, unified production network also restricted operators’ access to critical data, such as freezer temperatures. Two redundant human machine interfaces (HMIs) were the sole source for operational information about the refrigeration systems.
That limited line of sight and also created safety concerns.
If the site were to ever experience an accidental ammonia release, everyone would have to evacuate the building,” said Gary Bilger, distribution analyst at the MedImmune facility. “But unless you were standing at one of those terminals, you wouldn’t be able to trace the problem, diagnose it and help direct emergency responders.”
Meanwhile, accessing reports about temperature monitoring was cumbersome. That information was housed on databases that had to be backed up every six months to avoid overloading the system.
“We have to be able to pull that information quickly, especially in case of an FDA audit,” Bilger said. “We needed a solution to make that data more accessible and easy to interpret.”
As an FDA-licensed and regulated facility, the distribution center also required an automated solution that would segregate good manufacturing practice (GMP) from non-GMP data.
To further comply with FDA regulations, pharmaceutical operations need reliable equipment and readily available spare parts. But with so much dated hardware from so many vendors, complying with those requirements posed a growing challenge for the Louisville facility.
“We needed a state-of-the-art automation strategy to combine our automation islands on a unified common platform,” Heckmanski said. “With plans for the possible addition of another refrigeration system at the Louisville site, MedImmune also needed a robust, expandable infrastructure that could effectively handle the future process needs of the facility.”
MedImmune selected the PlantPAx® process automation system from Rockwell Automation – a scalable, plantwide control system – to gain fully integrated control over the Louisville center’s distribution operations. The project was implemented in phases to minimize downtime to the two freezers.
MedImmune partnered with Stone Technologies – a Solution Partner within the Rockwell Automation PartnerNetwork™ program – to implement phase one of the new system. That included installation of the facility’s core control infrastructure, a fully redundant, fiber-optic ring backbone enabled with EtherNet/IP™ connectivity.
Deployment of the freezers’ process control network quickly followed, including two new programmable automation controllers for each, and a third dedicated to segregating and archiving GMP data. All electronic components associated with the two freezers were replaced.
Phase one also included the creation of a virtual environment using VMware® to save on space, as well as the high costs that come with purchasing, commissioning and maintaining multiple physical servers.
In phase two, MedImmune engaged directly with Rockwell Automation to design and implement a new conveyor and control system, and integrate it with the PlantPAx system for plantwide control.
“Each of the conveyors systems had somewhere north of 500 I/O and were not well-documented,” Heckmanski said. “Using their code-transfer tools, the Rockwell Automation design and engineering team was able to extract the existing code with 80 to 85 percent accuracy. They did the minor modifications in their facility and brought the new control system into our distribution center ready to go.”
Phase three – addressing the automated storage and retrieval system for each freezer – is under way. Besides new controllers for the system, the legacy crane equipment will eventually be replaced with a full complement of Rockwell Automation equipment, including new drives and remote, reset-overload capabilities.
“With the reset, our operators won’t have to go into a minus 25-degree environment to reset a trip. They can just push a button on an HMI,” Heckmanski said. “From a safety standpoint, the more information the operator can access outside the freezer, the better.”
The ease of implementing the modern DCS system helped shave weeks off the original timeline. MedImmune leveraged the Rockwell Automation library of process objects to minimize development and testing time, allowing them to finish phase one six weeks ahead of schedule.
Virtualizing the system servers provided significant savings in time, too. System setup and software installation was reduced from a typical two weeks to eight days.
“We were surprised how much time we saved overall,” Heckmanski said. “In particular, reducing the anticipated downtime of the refrigeration system by over 20 percent was huge because the freezers are the most essential element of the facility’s operation. The longer they sat at ambient, the longer it would have taken to come back down to the validated temperature.”
The PlantPAx platform has provided MedImmune with all the components needed for regulatory compliance in a single, plantwide solution, opposed to the islands of automation previously deployed at the facility. Availability of centralized GMP data delivered by the new system helps the company easily pull any required information required for an FDA audit.
In addition, the facility’s process systems now operate with greater efficiency and ease of access for operators and maintenance personnel, though MedImmune is still quantifying those benefits as it moves through phase three of the project and beyond.
“The seamless integration and compatibility of components with the PlantPAx system will reduce risk when we replace other aging equipment and continue to upgrade the facility,” Bilger said. “Once everything is connected to the system, we can really explore all the bells and whistles. We are really just scratching the surface of what the system will enable us to do.”
The results mentioned above are specific to MedImmune’s use of Rockwell Automation products and services, in conjunction with other products. Specific results may vary for other customers.
