Coaters Armed

Pharmaceutical systems integration specialist, Optimal Industrial Automation, is reporting increased interest from across the industry in automation and mid-life upgrades to tablet coating equipment. The company, which has automated around 50 such machines for clients all over the world, attributes this demand to three factors: the rising importance of advanced coatings as part of the delivery system in many pharmaceutical products, regulatory pressure to improve process control and reliability in all aspects of the drug production process, and the fact that coating can be a key bottleneck in the manufacturing value chain.

The addition of latest generation control hardware and software can deliver significant benefits in each of these areas, even on equipment that has already been in operation for many years. Automation of key process parameters allows companies to control coating thickness and performance characteristics more tightly, for example, and enables the introduction of in-process sampling and closed loop control for further manufacturing quality improvements.

Integration of tablet coater control into a plant’s shop floor data acquisition systems also simplifies and improves the reliability of record keeping to comply with regulatory requirements and enable systematic continuous improvement efforts. Automation can also offer significant throughput increases, by accelerating product changeovers, for example, or allowing integration with automated feeding and unloading equipment. As a further benefit, new control technologies can bring older equipment into compliance with the latest workplace safety regulations, a particularly important factor for solvent-based coating systems.

“The mechanical systems in tablet coating machines can typically operate reliably for decades,” says Ron Esain, director and senior project manager at Optimal, “It is usually the limitations of older generation control technologies that determines the useful service life of this equipment, so a mid-life upgrade is an extremely cost-effective way for companies to get more value out what is often a highly significant investment.”

A full upgrade to the control systems on a production-scale tablet coating machine can cost less than half the price of a new machine, and Optimal has used its extensive experience of the full range of downstream pharmaceutical manufacturing technologies to build a range of standard control templates, customisable to the needs of individual clients, which further reduce the time, effort and cost of developing reliable, regulatory compliant control strategies.

One recent project, completed for a blue chip pharmaceutical client, comprised the integration of a fully automatic system using a Siemens S7 400 PLC at its heart with GE iFIX client server SCADA at the top end. The system included a full and comprehensive recipe system plus all the necessary CIP functionality. Batch reports were generated for use as part of the product’s life cycle documentation, and all salient parameters were recorded in the SCADA’s database for future use and process optimization.

The quick and cost effective nature of such projects also helps pharma players to manage their longer-term investment risk “in the future, many companies expect to make the transition from batch to continuous coating processes,” notes Esain. “By updating the control technologies on their current generation equipment, they have the opportunity to delay such investment decisions until they have a clearer picture of their roadmap to continuous production.”

Photo Captions

Picture 1: Coated tablets example.

Picture 2: Siemens S7 400 plc used to upgrade tablet coating machine.