Quality Control in High Speed Inhaler Testing

Ensuring the highest quality standards in metered dose inhaler (MDI) production is essential for patient safety and regulatory compliance. Each inhaler must contain a precise amount of liquefied gas propellant under pressure to generate an effective aerosol. Detecting leaks in these canisters is critical, as even a minor defect can lead to reduced drug efficacy or total product failure.

Traditional manual off-line leak testing methods are prone to inefficiencies, including:

• Slow processing times, limiting overall production volume.
• High rejection rates that can result in the disposal of entire batches due to a single faulty unit and limited accuracy, since sampling only a few items per batch may allow defective products to reach the market.

To overcome these limitations, the manufacturer sought an automated, high-speed solution to improve quality control while maintaining production efficiency.

"We knew that the application would require a high level of accuracy and repeatability in position control to effectively move and monitor the pMDI canisters. Mitsubishi Electric offers very reliable and accomplished small robots which are easy to synchronise and control, using powerful controllers and intuitive software. We also appreciate the technical support and assistance offered, which helps to deliver the type of advanced tailor-made solutions we specialise in."
— Nigel Penny, Project Manager, Optimal Industrial Automation

To address these challenges, Optimal Industrial Automation and Mitsubishi Electric collaborated to develop a state-of-the-art, fully automated leak detection system. The key components of this solution include:

• Two Mitsubishi Electric FR-Series SCARA robots that precisely pick and position MDI canisters into moving pucks.
• MELSEC iQ-Platform PLC for seamless synchronisation between robots, conveyors, and testing equipment.
• MAPS SCADA software for real-time monitoring, data logging, and process optimisation.
• An 86-cavity puck conveyor system, designed to transport canisters through a sealed testing tunnel.
• Advanced laser gas analysers, which detect even the smallest gas leaks with unmatched sensitivity.

The SCARA robots are especially important, because they ensure that canisters are accurately positioned into the moving pucks for continuous, in-line testing. This eliminates the need to stop the conveyor, allowing for uninterrupted production and higher throughput.

"Synchronisation on this line is critical because the canisters are unstable and may topple unless the motion of the robots and conveyors matches perfectly," explains Martin Gadsby, Director at Optimal Industrial Automation.

Critical to meeting the demanding timing and reporting requirements of the new line was a control solution offering ultra-responsive command processing and seamless data capture. In his own words, Steve Kirby of Mitsubishi Electric explains how their platform rises to this challenge:

"The iQ series PLC is ideal to meet the levels of speed and accuracy required by the system. The controller executes command processes in a matter of nanoseconds. It also offers a high-speed data logger module, where the sampling function is synchronised with the sequence scan," adds Steve Kirby, Key Account Manager at Mitsubishi Electric.

Operators can monitor the process in real time via Mitsubishi Electric’s SCADA platform, which collects and logs analytical data for each canister. This not only enhances traceability but also enables data-driven decision-making to optimise production processes further.

By implementing this fully automated quality control system, the manufacturer achieved:

• 30x improvement in leak detection rates, enhancing product reliability and compliance.
• Processing speed of 180 canisters per minute, significantly increasing production efficiency.
• Drastic waste reduction, as only defective units are discarded rather than entire batches.
• Optimised resource utilisation, lowering costs and improving sustainability.
• Seamless integration with existing production lines, minimising downtime during implementation.

In the weeks after commissioning, the upgraded line delivered on its promise of higher throughput and steadier cycle times, with operators noting a marked reduction in unplanned stops. Behind the scenes, engineers from both companies worked in tandem to iron out any teething issues, ensuring that integration stayed on schedule. Their hands-on approach to problem-solving helped the system hit its performance targets almost immediately.

"It has been a real pleasure working with Mitsubishi Electric and we are extremely satisfied with the project's outcome. The company's extensive capabilities in factory automation were crucial to deliver the high level of performance and accuracy required by the production and testing line. In addition, the expert engineers established a close collaboration with Optimal and the end customer in order to deliver a highly effective system and a smooth handover."
— Nigel Penny, Project Manager, Optimal Industrial Automation

This case study highlights how advanced robotics and automation are revolutionising pharmaceutical manufacturing. By integrating high-speed, fully synchronised automation, manufacturers can achieve:

• Increased precision and accuracy in leak detection.
• Reduced waste and cost savings.
• Improved compliance with regulatory standards.
• Increased overall production output.

The success of this solution demonstrates Mitsubishi Electric’s commitment to driving innovation in pharmaceutical quality control.

"We are delighted to have been involved in this project and help set up a highly effective system. The application proves how advanced robots and automation equipment can improve quality control in highly regulated sectors such as the pharmaceutical and life science industry." — Steve Kirby, Key Account Manager, Mitsubishi Electric