During MEDTEC 2018, Spang & Brands GmbH from Friedrichsdorf, Germany exhibits a large number of medical devices. These demonstrate the company's performance capability as a complete solution supplier, encompassing processing, packaging and labelling. It involves single- and multi-component injection moulded precision and micro products, such as connecting elements, functional parts for infusion solution bags and closure systems. Pierceable membranes, cannulae, syringes, implants, components for minimally invasive surgery and assembled groups of components are also on display. Furthermore, Spang & Brands presents a sterile bag sealing system made out of two plastic components with proof of originality (TPC: temper-proof cap). The company also presents sterile connectors, 2-port bottle-pack caps with sealing elements in TPE, break opening caps made out of various plastic components and material combinations.
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Disposable nasal doser |
On the basis of these plastic exhibits, interested parties can find out in technical discussions with the exhibitor which route a product takes throughout the entire value chain: from the initial idea, the first 3D design, through the various stations in the new technology centre, right up to mould sampling and production process conditions - including validation, which is an integral part of the entire process.
Validation is one of the most dominant and overriding topics in the medical device value chain of a company such as Spang & Brands that is certified according to DIN 13485. Toolmaking for medical devices in plastic differs fundamentally here from toolmaking in automotive and white goods sectors, for example. Risk assessment of moulds for medical devices is much more demanding: even an injection mould has to comply with typical regulations that are common in medical technology. “For such tools, risk assessments must be carried out and documented accordingly. This is what validation is all about”, explains Friedrich Echterdiek, CEO of Spang & Brands GmbH. "Process optimisation and traceability are essential: when looking at the customer and ultimately the patient, it is important to be able to prove the origin of the individual components and the various process stages on the way to fault-free medical devices. It is for this purpose that Spang & Brands appointed a validation officer in 2016 to work seamlessly with quality assurance and report directly to the company management".
Validation covers four areas, three technical and one informative. The latter is called Design Qualification (DQ), the others are Operational Qualification (OQ), Installation Qualification (IQ) and Performance Qualification (PQ). "For an assembly, comprehensive validation is never complete, it continues throughout the life cycle of the project," says Dominic Mader, Project Development Medical Devices.
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810 individual (superimposed) measurement results for only one of numerous (n.n.) different process parameter variables. Explanation: |
In DQ, plans, offers, qualification, error & risk analyses are combined and drawings are always kept up-to-date. The document describes where everything can be found and is therefore an aid for the user. Mader says: "We have to deal with TUV and DIN standards, as well as other demands that are placed on us. Everything is put together from a practical point of view. After all, our customers expect compliance with these standards. They serve above all as a tool for us to prepare our processes absolutely transparently".
With technical validation steps, it is ensured that production takes place within an exact tolerance window. The CpK statistical value, which is determined for each inspection characteristic, is crucial. It is the most important parameter describing process capability. It contains information on both the spread of values and deviation within tolerance limits. Mader explains: "We produce within a strictly scientific framework. A component not only has dimensions relating to connection such as length, width and height, but also certain functional dimensions. But we also validate aspects such as weight, internal pressure curves, internal pressure integrals, break off behaviour, among others. With validation, I can set the course for a future product with an optimum CpK value".
DQ is hard work that begins from the very first moment, even before order confirmation (with feasibility analysis, risk assessment, etc.) and then it also accompanies the project. Installation qualification (IQ) documents correct implementation of requirements previously defined in e.g. Design Qualification (DQ). Operational Qualification (OQ) and Performance Qualification (PQ) are both very labour-intensive processes with regular verification, which can, in principle, take a very long time. For example, processing of semi-crystalline plastics is a challenge, as it is difficult to calculate dimensional shrinkage. This means the tool has to be kept under control, in order to be able to influence production: "Temperature, for example, can only be varied within a certain window. Tool and melt temperature influence the moulded part’s shrinkage behaviour and therefore also its dimensional stability", says Mader. This process of flexible production is familiarised and documented with OQ. This requires well-qualified staff who can also contribute with their own experience. Quality assurance is applied systematically at Spang & Brands: short-term tests are important, but even more fundamental are long-term tests that have been carried out at Spang & Brands for years and guarantee lasting product quality.
Beyond and within validation as such, there are questions of how testing is performed and how process parameters can influence component properties, and which parameters are key to guarantee a stable process. For example, with the "Nosy" applicator for nasal drug administration, its design involved determination of which nozzle hole geometry would be suitable to ensure oscillation of the fluid and therefore easy handling for the patient. Reproducibility of the nozzle hole was ensured during validation, without even slightest deviation. Mader says: "Evaluation is made already in our technology centre on exactly what is possible and what is not. The practical details are then evaluated with OQ and PQ". Important standards such as ISO 13485, GMP (Good Medical Practice) and many others are only "pre-theories" for Spang & Brands as a basis for its own validation procedure, which is enriched with incredibly large amounts of data from IQ, OQ and PQ, in order to determine the best CpK value for each component.
Injection moulds as well as the injection moulding machine and its ancillary equipment are used as instruments for validation. Mader points out that a production run must first take place in order to have a fixed value, the so-called initial sample test report, on which validation is then based. Spang & Brands has standard requirements for its products, but individual validation can also however be carried out with the customer. "If IQ is more important to the customer than OQ, this can be worked out individually," the expert emphasizes.
Validation generates extremely large amounts of data, with which the best production process can also be visualized. Up to 5,000 values for just one process variable are not uncommon. Four to eight process variables are usually investigated. So coloured classic mathematical X/Y axis charts show how parameters such as injection speed, mould and melt temperature at different pressures relate to each other. Colour highlighting shows the CpK value expected in production. A CpK value above 1.67 is optimal and production is still sure up to 1.33. But while production is possible up to 1, it is not recommended. A CpK figure is also used to illustrate target limits for mean value and standard deviations.
Dominic Mader created the attached screenshot as an example - from 810 individual (superimposed) measurement results for a single cavity mould and for only one among numerous (n.n.) variables. The result: this process determination leads to optimisation... so that "everything is in an acceptable area".
A small validation can take a working week, but validations can also take years. They are a particular challenge in the medical industry. Moulds with 96 or many more cavities are often used for single-use mass-produced components such as syringes, cannulae or tubing systems, which are produced in short cycle times. It is very complex and difficult to implement this along with compliance with regulatory requirements. Spang & Brands is one of the few medical device producers to meet these challenges in ongoing dialogue with its customers.
During the fair, Messrs Echterdiek, Mader and Lilly are available for questions and answers.
About Spang & Brands
Spang & Brands has specialised in precision and cleanroom injection moulding technology for the medical and pharmaceutical industry for over 35 years. In addition to its own products, the company sees itself above all as a competent contract partner for customer projects. Product innovations at Spang & Brands go through all process stages - from the idea to the finished product, ready-to-use. The company ensures consistency of CAD tool data and maximum precision in CAM production of moulds for medical and pharmaceutical devices in its own technology centre. Spang & Brands has at its disposal latest equipment, as well as a team with a high level of competence and experience, which masters the technology: part development, mould design and construction, injection moulding with 70 mainly electric drive single and multi-component machines, as well as the subject of cleanroom production. Fully automatic and manual assembly and packaging of parts and assemblies are located in cleanrooms - from pre-series or just-in-time batch sizes, extremely small series, and right up to full production running into millions of products. Strategically positioned control points and 3D measuring technology support quality assurance.
