Improving the quality of pharmaceutical packaging components
Ensuring that rubber stoppers and plungers used in pharmaceutical vials and syringes are free from defects and contamination is of paramount importance. The iM series of modular, fully automated inspection machines manufactured by Simac Masic bv have been designed to meet that challenge.
Utilising multi-camera high-speed vision systems, developed in conjunction with STEMMER IMAGING, in combination with metal detection, they provide 100% inspection of these products and provide automatic rejection of out-of-specification product.
Huge quantities of rubber stoppers and plungers of different sizes are manufactured for the pharmaceutical industry each year using many different elastomer materials. The stoppers are used to seal drug products in a vial and are held in place by an aluminium cap. They feature a hollow central plug and in use, a syringe needle is inserted through the stopper.
When the vial is inverted, the medication flows into the hollow plug allowing it to be extracted through the needle. The plunger forms an airtight movable seal in the syringe body that allows the medication to be drawn into the syringe. The elastomer stoppers and plungers are potential sources of particulate contamination and since both come into contact with the drug product itself, this could lead to costly end of line product rejection or even compromise patient safety.
Industry expertise meets the challenge
Simac has been involved in the design and production of rubber stopper inspection machines for around 25 years so has extensive experience in this field. Each new generation of their inspection machines is designed to address the increasing requirements of the industry.
Key considerations include:
- The speed, accuracy and reproducibility of inspection
- Imaging the internal bore of stoppers and plungers
- High speed, high volume data handling
- Mechanical handling to allow inspection of all surfaces
- Mechanical handling of different size stoppers and plungers in the same machine
- Meeting CFR21 Pt 11 and GAMP5 requirements
- Ensuring the system can be used in an ISO Class 5 clean room environment
In addition, many stopper and plunger manufacturers also want to make dimensional measurements and check for the presence or absence of any inert elastomer coatings that have been applied, so the system needs to be able to meet these needs.
Self-contained system with modular design
Vision inspection
A vibratory bowl feeder receives the parts from a hopper and then orients them onto an accumulation track. A rotating separation wheel collects the stoppers one by one from the accumulation track and transfers them to a rotating mechanical vacuum wheel which presents them to the first vision station. Here two high resolution cameras are used to inspect the top of the stopper and the steep internal sidewalls of the hollow plug for defects such as marks, cosmetic defects, inclusions, dents, particulate debris, fibres etc. Inspection of the cavity and inner walls of the stopper is particularly demanding, requiring precise positioning and careful attention to the lighting and lenses used.
A similar approach is used for the plungers, but as the cavities here are much smaller, a different camera with wide angle lensing is used. Since the stoppers and plungers can be made from a wide range of elastomer compounds, colour cameras are used to ensure that light coloured defects on light product compounds can be detected. A pneumatic ejector blows all components that fail these inspections off the wheel and into a reject bin.
Parts that pass the inspection remain on the rotating wheel and are then transferred onto a larger, uniquely designed rotating ring, which transports them through the second vision station and metal detector. They are given an identification key so that they can be tracked through this process.
The second vision station consists of a compact camera aisle on which multiple cameras are mounted. Four of these cameras are arranged around the component to provide a full view of the entire side surfaces of the component. One of these cameras looks down to image the bottom surface of the top of the stopper. These inspections are triggered simultaneously. There is also space on this camera aisle to mount optional cameras for dimensional measurements and inert surface coating inspection.
The component then passes through a metal detector to check for embedded metal particulates that may have come from the moulding process. On completion of this inspection, the components pass to another pneumatic ejector system. Failed components are blown into a reject bin, while good parts are blown into either an acceptance bin or a QA sampling bin for subsequent manual inspection. The proportion of good components that are sampled for QA is specified by the manufacturer and set up in the inspection recipe. The system is capable of inspecting 700 components or more per minute, depending on the design of the components.
System performance
Enhanced productivity
A touch screen interface provides access to all machine functions and any changes and adjustments are displayed in ‘real-time’. Batch information can be entered and recipes can be selected for the particular components being inspected. The operator can follow statistics, processing results and operationally-check the current product run. A separate vision terminal shows images and vision inspection results.
Roberto Griguoli concludes: “Key factors that characterise our machines are performance and the potential to go further. In the current generation of machines we have increased the speed, the reliability of error detection and the accuracy of detection.
Defect detection levels are >99% and the current inspection speeds are limited by the mechanical feeder system – the imaging system could handle a faster inspection rate. We can also offer additional inspection modules but we are always happy to speak to manufacturers about their specific needs and carry out additional customisation if needed. We provide comprehensive customer support including remote access to monitor machine status if needed.”
Simac’s latest iM range of rubber stopper and plunger inspection machines enable top-of-the-range pharmaceutical component suppliers to deliver products that have been automatically 100% verified to be free of specified defects and contamination. Designed, engineered and manufactured in house according to GAMP standards, these new machines precisely meet the needs of the industry.
Pushing machine vision to the limits
About Simac Masic bv
Simac Techniek N.V. was founded in 1971. Operating as a family business across Benelux and Central Europe, it supplies and supports high-quality technology solutions for improving the business processes of large and medium-sized organisations. The Simac operating companies offer a wide range of solutions, products and services in the ICT infrastructure, ICT applications and Industrial Electronics & Automation business sectors.
Simac Masic bv is part of the “Smart Solutions” group of companies within Simac and a global supplier of machine vision systems to a number of industries including pharmaceutical, medical, food, electronics, and packaging. Since the delivery of its first vision system in the 1990s, the company not only provides complete turnkey solutions, but also supplies integration pathways for existing production lines. The last few years they focus mainly on medical and pharmaceutical applications to provide true technology leadership within these industries.