The role of the analytical chemist in today’s chemical industry is pretty much what it has always been — checking the quality of the final and intermediate products, and providing feedback to the plant so its operators can ensure that quality. But, as has happened to so many other professions, that role has become increasingly automated as traditional laboratory-based analytical techniques are moved online and even replaced by the virtual analysis offered by soft sensors and inferential measurements.
In many sectors such as refining and petrochemicals, online process analysis is the norm. Their high-throughput, low-margin operations can't afford the delays inherent in waiting for laboratory results to reveal whether or not a process is producing to specification. But other sectors, particularly pharmaceuticals, are relatively recent converts to the concept of moving the lab out into the plant. It was, after all, only three years ago that the U.S. Food and Drug Administration issued its guidance on Process Analytical Technology (PAT), "A framework for innovative pharmaceutical development, manufacturing, and quality assurance."
"The aim of PAT is to focus on the process rather than the end product. Processes are actively managed to achieve a high degree of repeatability and efficiency, and quality assurance becomes a continuous and real-time activity" (Figure 1), says Thomas Buijs of ABB Analytical, Québec, Canada.
Putting it all together
Buijs is line manager for development of a systems approach to PAT at ABB Analytical. Such an approach is crucial to PAT success, believes industry analyst Paula Hollywood of the ARC Advisory Group, Dedham, Mass. "Selecting and purchasing an analytical instrument for an in-process application the same way you would for a laboratory-based instrument is a recipe for failure," she says. "For pharmaceutical manufacturers struggling with what to do about the FDA's PAT initiative, early engagement with a strong engineered solutions supplier can bring much more to the process than standalone analytical devices."
In collaboration with one of its leading pharmaceutical industry customers, ABB this year unveiled its IndustrialIT for PAT solution, which Buijs describes as "a product, a solution, and a service." In essence, the product takes in data from online (and offline where necessary) analytical instruments, consolidates the data and provides information to the process control system for feedback control.
"The main PAT problem," Buijs says, "is a lack of interoperability between third party analyzers." ABB is addressing this problem by working with other vendors to enable their analytical data to be seamlessly linked, via OPC, to the FTSW800 software suite at the heart of the PAT product. This software supervises real-time spectra acquisition and property determination and supports the data processing algorithms. All the acquired data are stored in a single distributed database and the system can handle "huge" flows of both scalar and vector data coming from the analyzers.
Instrument vendors whose PAT analyzers can already link include Agilent (with its HPLC system), Mettler-Toledo (through its FBRM control interface software), Axsun (near infrared NIR analyzer), Ametek (mass spectrometer), Bruker (FT-NIR analyzer) and Zeiss (UV-Vis and NIR spectrometers).
Based on ABB's 800xA automation technology, IIT for PAT provides a local interface for data trending and operator interaction, as well as full connectivity to the plant's DCS or PLC control system. The service aspect, says Buijs, stems from the company's ability to look at the whole process, not just individual unit operations, and optimize the overall control strategy.
Siemens, Alpharetta, Ga., is another automation company leveraging its process control knowledge to encourage the uptake of PAT. Working in collaboration with analytical company Applikon Biotechnology, Schiedam, Netherlands, and the state-run Netherlands Vaccine Institute (NVI), Bilthoven, Netherlands, Siemens has developed its Sipat software to help with the implementation of PAT principles. The software brings together all the information flows during processing (in the development case, the cultivation of the Bordetella pertussis bacterium, a critical step in the manufacture of whooping cough vaccine) and enables online comparison of process and historical data. "The outcome is what we believe to be the very first automation system capable of developing and executing full PAT cultivation processes," says NVI project leader Mathieu Streefland.
Although software may be key to the success of a PAT implementation, the FDA initiative has given almost as big a boost to analytical hardware developments in recent years — and not just for pharmaceutical applications. For instance, Foss NIRSystems, Laurel, Md., says that, as a PAT tool, its XDS NIR analyzer is "the next generation of dedicated NIR technology for analyzing solid and liquid chemical and pharmaceutical formulations." In the form of the Foss Process Analytics MicroBundle single-point system, the technology also is said to offer an economical way of performing online remote analyses in hazardous environments.
The IntegraSpec XL NIR spectroscopy platform from Axsun Technologies, Billerica, Mass., is equally at home in a rugged in-line process environment or, in its XLP format, in tightly regulated PAT applications. Both versions are board-level platforms — complete with tunable-laser-based light source, integrated wavelength and amplitude references, and detector — that can be packaged and supplied through third-party analytical instrument manufacturers, systems integrators and process control companies. The XLP also includes comprehensive documentation to support Good Manufacturing Practice (GMP) regulatory compliance for pharmaceutical end-users.