Medicine at the touch of a button
Process visualization in the pharmaceutical industry

In the pharmaceutical industry, safety takes top priority. Both the final products and the manufacturing processes must fulfill stringent quality requirements. This also applies to the handling of production data. This is certainly not the least important reason why Siegfried in Zofingen usesSimatic WinCC as process visualization system in its grinding and mixing plants.

Companies in the pharmaceutical, cosmetics or food industry which manufacture products for the U.S. market must comply with the guidelines of the Food and Drug Administration (FDA) for plant validation and operation. Since 1997, U.S. authorities have been telling manufacturers which process data must be available, and in what form. Failure to comply can have devastating consequences, possibly even the revocation of product approval. In order to prevent this, the Siegfried pharmaceutical company chose the Simatic WinCC process visualization system for their new grinding and mixing plants. Bernhard Hunziker, project manager for Deleproject AG, which integrated the plant’s software, has no doubts whatsoever: “As far as FDA compliance is concerned, WinCC is the undisputed leader.”
Central operator control and monitoring
The FDA guidelines stipulate that Siegfried must record and be able to produce all process data for a thirteen-year period. This has a useful side effect. “The recorded data help us with process optimization,” says Roger Schärer, project manager at Siegfried. WinCC/Audit and Simatic Logon WinCC options also contribute to the two grinding and mixing plants’ FDA compliance. Whenever the system undergoes modification, WinCC/ Audit automatically records user, date and time, object, and old and new value, as well as comments. Simatic Logon, which is integrated in the Windows security and user management systems, can be used to define access privileges. In addition to the forwarding of data for archiving, the main advantage of the visualization system lies in its central operator control and plant monitoring capability. In this particular instance, each of the two grinding and mixing plants extends over five storeys. In these two plants, pre-synthetized, cleaned and crystallized pharmaceutical agents, for the most part psychopharmaceutical agents, are ground to the required particle size, homogenized, and packaged. By way of a filling plant, the substance goes first to a silo, where it is forwarded to the mill by a proportioning screw. Once the agent has been ground or sieved, it is homogenized in a screw mixer. Then, in a final step, the agent is packaged. Because of the danger of explosion, the entire process takes place in an atmosphere of nitrogen. In addition, a permanent overpressure of fifteen pascals must be maintained in the production rooms, and humidity and temperature must not exceed specific limits. High demands are also placed on the air quality. In production rooms in which samples are taken, the air quality comes close to that of the rooms in which chips are manufactured. At one time, all parameter modifications and settings required for this complex process and for ventilation had to be made manually. “Today, thanks to WinCC, we can monitor everything on the display and make the necessary adjustments. And every modification is automatically recorded,” says Schärer.

Closed plant preventscontamination
The visualization system permits separate selection of the ventilation area as well as the individual process areas in the plants, and tracking of the relevant process data. To make this possible, the nine Simatic S7-300 controllers used to automate the two plants are linked with the WinCC server over the company’s intranet. This also enables central control of the plants via the process visualization system. Operator panels located on each floor are used only for the fine adjustment of individual process steps. Automatic operation of the two plants via a WinCC client station located in a control room has a number of big advantages for Siegfried. For one thing, the working conditions have improved. For another, the plant can be operated in “closed shop” mode, — the product never comes into contact with the environment, preventing contamination, and the grinding and mixing process can be recipe-based. Entering the recipe numbers in PM-Batch, a WinCC add-on, is all that is necessary; the settings for the process as well as the subsequent cleansing of the plant are handled automatically. The new plants are also well-equipped for the future. At Siegfried, all process data, including audit trails, are transparent and are available for inclusion in a factory-wide information system with WinCC as data platform. Despite a commissioning time of only three months, the plant functioned extremely reliably from the very beginning. “Once the plant was up and running, almost nothing had to be changed,” said Schärer.