The impact of lean manufacturing methods on drug delivery devices

Alan Thomas from ZwickRoell examines how lean manufacturing methods spur innovations in the testing of drug delivery devices.

The number of people who live with diabetes is on the rise. The World Health Organisation (WHO) estimates that one in eleven people are affected by the disease. This makes the auto-injector market one of the fastest growing subsets of the pharmaceutical industry. Moreover, with the rise of biologic and sustained release drugs, the market will see an even greater demand for auto-injectors in the future.

Strict regulations by the Food and Drug Administration (FDA) for these class II devices mean that testing to ISO 11608-5 is a critical step for manufacturers in guaranteeing the quality and safety of its products. Whether testing is managed in-house or handled by a contract testing laboratory, for one or for many different product designs, these companies are turning to testing platforms that are both versatile and comprehensive. Testing must support manufacturing protocols and industry regulations, while maintaining absolute accuracy and reducing time to market.

As a result, concepts used in modern manufacturing have shaped product development. Best practices from lean manufacturing and other methods rooted in quality management systems are often part of the design process. Features based on ‘poka-yoke’ principles help auto-injector producers manage high volumes and maintain compliance with Good Manufacturing Practice (GMP) standards and FDA regulations at the same time, thereby reducing the potential for costly errors.

‘Poka-yoke’ systems, first established in Japan by car manufacturer Toyota, prevent inadvertent errors made by workers performing a process. Companies have benefitted by implementing such systems because they are able to eliminate set-up errors and decrease set-up times to boost production throughput, improve quality, increase safety, and lower costs. Implementing this type of ‘mistake proofing’, as it is sometimes called, has never been more crucial in the pharmaceutical and medical device industries, as companies strive to ensure compliance with regulatory requirements while providing next-generation products on which patients can rely.

In a high throughput testing environment where, for example, auto-injectors are manufactured, multiple operators use the testing system over the course of a production period. The gathered results are then evaluated to make decisions on product quality. Reducing the steps required to set up and run tests improves efficiency and substantially minimises the potential for inadvertent human error.

A typical market solution is a semi-automated testing machine that requires an operator to load the test specimen, close the safety door, and start the test. From that point forward, all steps in the test sequence are carried out automatically by the machine within just a few minutes per injector. To reduce the risk of operator errors even further, a robot-driven fully automated testing system removes the auto-injector from the cartridge and inserts it into the testing machine.

Typical tests performed by semi or fully automated solutions measure the cap removal, activation force, delivered volume, injection time and needle shield blocking force in one continuous process. Software directs the robot to remove insulin pens one by one from the magazine, feed them into the testing machine, and start the test. The test process is significantly more efficient because of increased specimen throughput. Test result accuracy also increases because operator influence is minimised.

Another way to reduce operator influence is by using barcodes as early as the test set-up phase. A barcode and Bluetooth integration feature ensures consistent selection of jaw faces and grips when running tests, because every auto-injector type has a slightly different design and requires a unique test set-up. First, the correct jaw face and grips are selected, and their configuration is saved in the software, so it is impossible to start a test with the wrong accessories. Then, a Bluetooth transmitter in the auto-injector testing system works together with a special barcode reader to help the operator simplify test set-up. Before the operator starts the test, the testing software specifies the exact tooling needed for that specific test and auto-injector. The operator selects the corresponding grips and uses the barcode to scan the jaw face. The software then validates the selection of the correct configuration, allowing the test to continue. If the operator chooses the wrong grip, the software does not allow the test to start and prompts the operator to choose the grip that corresponds to the type of auto-injector being tested. Grips and jaw faces are also colour-coded to visually aid the selection of the right tooling.

Furthermore, medical device product development is subject to many regulations that require test, and system-relevant actions and settings to be logged. Regulation 21 CFR Part 11 on electronic records and electronic signatures of the United States FDA defines acceptance criteria for the use of electronic records and electronic signatures in place of records in paper form and handwritten signatures on paper. These electronic documents must be handled with as much confidentiality, be just as authoritative, and hold the same value as the paper documents. Testing software that makes it possible to create documentation for the testing process that is complete and tamper proof is vital for companies subjected to the regulated areas of the medical and pharmaceutical industry.

Growth in market demand for auto-injectors is placing greater emphasis on throughput. Yet accurate test results are critical when it comes to patient health. This challenge has motivated manufacturers to seek solutions that streamline and automate the testing process without sacrificing accuracy, repeatability, reproducibility, and traceability. Implementation of mistake-proofing mechanisms ensures consistency in testing programs, further elevating accuracy in measurement and supporting excellence in manufacturing that complies with GMP standards and FDA regulations.