Analyzers have been used for many years in pharma/biotech R&D and manufacturing. Rather than just measuring temperature, pressure, pH, and so on, an analyzer can provide multiple data points or, potentially, a spectrum of data.
There are many analyzers available today that are based on NIR (near infrared), diode array, Raman, and other technologies, each of which enables presentation of very specific data—data that is not presented when using traditional process measurements. Most of the instruments include proprietary “analyzer controllers” that allow the user to configure as well as gather vital data, such as that for process information, alarms, and instrument health.
Methods for pulling analytical and decision-making information out of analyzers vary—typically, via a serial interface, a 4-20 mA signal or some form of OPC communication. But the information that is transferred or pulled from the instrument is typically “pre-processed” and does not contain all of the information that could be helpful in evaluating the process. In addition, all analyzers use different protocols for their interfaces, making it difficult and costly to tie multiple analyzers together to get the total picture of the process.
Analyzer integration for Process Analytical Technology (PAT) presents a unique set of challenges. There are varied analyzers, supplied by multiple vendors, which utilize multiple data-exchange protocols to provide many different types of critical data. The best way to accomplish the level of analyzer integration required for PAT is through broadly adopted, open standards.
Similar issues have existed with process instrumentation, as well as with computer interfaces to different printers. A specific driver or a “one off” serial interface is required to allow communication with different suppliers’ instruments, printers, etc. The solution was to develop open standards and protocols that would allow easy connection, identification, configuration, and use of the instrumentation and/or printers. From a process instrumentation standpoint, this was accomplished with open standards such as Profibus, HART and FOUNDATION Fieldbus. Instrumentation suppliers developed new technologies that would allow automation control systems to use the same open standards or bus technology to tie into and communicate with multiple instruments, from multiple suppliers.
Towards an Analyzer Device Integration Model
Since its launch in February 2008, the OPC Foundation Analyzer Device Integration (ADI) Group, comprised of suppliers, end users, and systems integrators, has steadily developed in terms of numbers of participants and its importance to the pharmaceutical industry with regard to becoming one of the key instruments enabling and expediting future PAT and Quality by Design (QbD) initiatives.
The OPC Foundation working group has members representing both PAT and laboratory activities, while end users include Abbott, Bristol-Myers Squibb, GlaxoSmithKline, Novartis, and Pfizer. Vendors include ABB, Bruker Optics, CAS, Foss, Kaiser Optical Systems, Malvern Instruments, Mettler-Toledo AutoChem, Siemens, Sentronic, Software Toolbox, Sympatec, Thermo Fisher Scientific, Umetrics, and Yokogawa. Together, they are developing an information model for analyzer devices to allow plug-and-play multivendor interoperability. This model allows users to configure, operate, monitor states and expose status and data in a standardized way. It works for both process and laboratory analyzers. The model is a logical extension of the OPC UA specifications. The release candidate of the specification was published on September 9, 2009. Final release is expected within the next few months.
The OPC Foundation completed the OPC Analyzer Device Integration draft specification for review in December 2008. At the ACHEMA 2009 Fair (in Frankfurt in May), ABB demonstrated an NIR spectrometer simulator based on the ADI draft specification, connected to the OPC Unified Architecture (UA) client for OSIsoft PI historian. OPC UA is designed to facilitate building complex systems that are composed of products from multiple vendors. It’s also designed to provide the infrastructure for responding to both simple and complex information integration opportunities.
The OPC UA ADI interface supports a wide range of existing and future analyzers including but not limited to: Spectrometers (IR/NIR, Visible, UV, Raman), particle size analyzers, chromatographs (gas, liquid), acoustic and TeraHertz spectrometers, nuclear magnetic resonance spectrometers, mass spectrometers, automated microscopy and imaging systems (Visible, NIR, Cell Counting, etc.).
Reaping the Benefits
With the introduction and acceptance of the OPC UA ADI standard, PAT solutions will enable implementers to:
- Integrate third-party analyzers into a common database
- Time-align data for ease of analysis and control
- Integrate with any third-party control system
- Reduce variability of process by measuring critical quality attributes (CQA’s) and controlling critical process parameters (CPP’s)
- Utilize an object library to reduce set-up, validation and documentation time and expense
The release of this highly anticipated new specification follows the OPC Foundation’s founding principles of providing end-users with the ability to implement Quality by Design in their manufacturing systems. Process analyzers will no longer be isolated, proprietary systems. They will be based on OPC UA ADI specifications and have the ability to easily interact with complete plant systems through open communications. This will ultimately facilitate access to better process related data, from a variety of different instruments; all to be tied into a single control system for monitoring, data analysis, process modeling and closed-loop process control. In addition, it will help reduce manufacturing time and improve the quality and yield of end product.