Very stringent hygiene standards are specified for production conditions for manufacturing medicines. It is therefore very important that the production takes place in an environment that is free of germs, particles, bacteria and contaminating oils. The compressed air utilised is also therefore subjected to high requirements e.g. in the form of sterile compressed air or oil-free compressed air because it often comes into direct contact with the product itself in the production processes of the pharmaceutical industry. Compressed air is however, in contrast to the clean room air, not sufficiently monitored in practice and therefore represents a potential risk of contamination.
There are various guidelines and directives, such as GMP, FDA and the European Pharmacopoeia, in which compressed air quality classes are defined for applications. In order to comply with the provisions stated, continuous monitoring (24/7) is important so that deviations can be detected at an early stage and remedied.
The requirements are still not often clearly formulated and the implications for the whole plant or system are not described. We will therefore be very pleased to assist you to determine the quality class, as well as the appropriate design of your compressed air processing and treatment.
The tableting process is still the most important pharmaceutical processes for the manufacture of medicinal products. The process for manufacturing tablets always requires compressed air and it often also comes into direct contact with the product. This direct product contact occurs after the tablet press where compressed air is utilised to remove dust or faulty products are sorted out. Oil-free and dry air is important here otherwise, for example, the pressed tablets could swell up. Compressed air can also be used for applying lubricants onto the tablet press so that the tablets can be ejected easier.
Compressed air is already utilised at the initial stages for mixing the powder mixture and/or the production of the granules for the tablet press. The stages after the presses, the so-called coating, i.e. the coating and/or the encapsulation also utilise compressed air. A common method is the fluidised bed process whereby an air flow ensures that the tablets hover and are constantly in motion. They are sprayed, evenly moistened and dried by utilising spray nozzles. Compressed air is utilised here and in other methods as atomisation air.
Typical problems in the manufacture of tablets, in addition to the health risks for the consumer, are blistering, cracks or breaks in tablets or colour variations. Moist and oil-contaminated compressed air can be a reason for this. Due to the strict requirements in place, there is a recommendation for compressed air quality class 1-1-1.
On the one hand, machines must be cleaned and, on the other hand, the vials, ampoules and bottles, in which the medical products are filled must also be cleaned. The CIP cleaning process (Clean In Place) has been established for cleaning of plants, systems and containers. Compressed air is utilised here for drying. Dry ice blasting is an addition method for cleaning. The dry ice impacts on the surface to be cleaned and loosens deposits. The loosened deposits are then blown off with compressed air.
The filter in the fluidised bed plants must be cleaned during production. This can be executed via a filter blow-out system. Material residues will therefore be routed back into the process with compressed air. There is also a direct product contact here whereby high requirements for the quality of the compressed air must be achieved.
Another field is the cleaning of vials, bottles and ampoules, the compressed air is utilised here to dry the containers and remove the last remaining particles. This is often takes place in a sterile area, the compressed air must therefore be processed and treated with a sterile filter in such a way that it is very dry and germ-free.
Compressed air is often also utilised in the pharmaceutical industry for transporting integral elements for the production process e.g. bulk solids, liquids, powders and granules. Pneumatic conveying can be executed via compressed air or under vacuum. The finished products, such as tablets and capsules, are also transported back and forth between the individual processing units with compressed air. Transporting with compressed air prevents damage to the medicinal products, but a consistent quality of the compressed air is therefore required. The German VDMA recommends a compressed air quality of sterile 1-3-1 for transporting raw materials and finished products.
Compressed air is used on packaging plants and systems e.g. for transporting products and packaging or for packing and sealing of packaging. A controlled atmosphere will be created around the product with highly hygroscopic (water attracting) products, such as e.g. pharmaceuticals. Very dry compressed air must be present (inflating bags etc.), especially at packing positions when packaging pharmaceuticals.
There is often centralised compressed air processing, therefore the compressed air must be transported to the application. It is possible that the compressed air is supplemented with water again on this route. Hygroscopic substances react with the moisture from the ambient air. In order to ensure the product quality, contact of the humidity with the product must be prevented. For this reason, an additional compressed-air drying is required directly on the packaging machine.
If active ingredients are filled in ampoules and vials and then sealed, then a sterile environment is required.
Compressed air is utilised as the control air in the pharmaceutical industry for regulating production plants and systems e.g. via a regulating valve and cylinder. Lower requirements are normally valid for the control air as it does not come into direct contact with the product. There are however exceptions: The control air is subjected to special requirements in clean rooms. This also applies if the control air could affect the process.
When the compressed air does not comply with requirements, then a malfunction of pneumatic tools and machines can occur, lead to corrosion in pipework, cylinders and other components as well as freezing in exposed services during cold weather. This creates a threat of increased downtimes as well as maintenance costs for pneumatic machines, tools and control systems. The correct compressed air processing and treatment as well as periodic monitoring and maintenance is therefore essential.