Compact direct compression line A New Era of Continuous Tablet Production
Apart from process safety and product quality, one particular aspect is of major importance for a tableting plant: efficiency. The machine should be as economical as possible, while taking up a minimum of space. Instead of being oversized and complex, it should be compact and simple. In the form of a direct compression line, Fette Compacting is ushering in a new era for the continuous production of pharmaceuticals and food.
Continuous manufacturing has long been applied in pharmaceutical and nutritional production and is associated with tangible benefits. This is because integrated processes increase efficiency and process reliability compared to batch processes. Process development is faster, while production output increases at the same time. As a result, products can be launched onto the market faster and production processes can be designed more flexibly.
Although the continuous direct compression process is gaining in popularity among many tablet manufacturers, not all reservations have been dispelled to date. Batch-to-batch production is still the standard at many companies. There are many reasons for this, some of which can be traced back to long-standing reservations about a changeover: too expensive, too complex, too time-consuming to implement. Unfortunately, this outdated skepticism all too often obscures the numerous advantages incurred by the leaner plant design of a direct compression line.
One of the biggest disadvantages of classic continuous plants is their size. Tablet manufacturers are often obliged to add on or convert existing buildings to accommodate the plants, some of which are several floors high. In addition, continuous lines require long lead times for design and production, as the systems have to be customized. Both of these aspects have a negative impact on costs.
The new continuous tabletting shows what economically viable continuous production must look like: less complex and more easily adaptable.
In addition, scientific personnel are usually required to set up the system and specially-trained staff are needed to operate it. Combined with the time-consuming cleaning and retooling processes, this means potentially long downtimes accompanied by high investment and operating costs for companies.
The Solution: Become Compact and Simple
Based on the problem description, conclusions can be drawn as to what economically viable continuous production must look like: It should be less complex and more easily adaptable. One crucial prerequisite for this is the direct compression process, which makes upstream granulation processes obsolete and, due to its lower technological complexity, enables more flexibility and faster product changes. With the help of lean designs and a simplified process chain, the production process is reduced to three to four steps and requires less equipment. This significantly reduces the space required compared to other systems.
The Next Step: Modularity
Building on this, Fette Compacting has been able to make a technological leap: the continuous tableting system consists of a closed dosing-mixing unit including the FE CPS powder transport system, an FE55 tablet press, and an operating terminal. The entire system can be integrated into existing production areas at a single height level. This reduces structural investments to a minimum.
The modular design allows flexible arrangement and installation of the process units in a total area of 5 × 10 m at the maximum, including all free areas for handling materials. If space is limited, the footprint can even be reduced to 5 × 6.5 m. Alternatively, the system can also be set up on two levels.
Maximum Flexibility With a Wide Range of Tablet Types
The FE CPS processes a wide range of formulations with throughput margins from about 5 to 200 kg/h. It thus offers a high degree of process flexibility — from product development to smaller batches and large-volume production. This is made possible by the FE 55 all-round tablet press, which is able to handle a wide range of different tablet types.
With three instead of two compression stations, the rotary press enables longer pressure holding times at lower pressures. This results in gentler processing and an even more flexible tableting process. Such an overall design is also suitable for a multiple unit pellet system (MUPS), in which the formulations to be processed can accidentally segregate. With the FE CPS, segregation processes can be effectively reduced.
The Result: 100 Percent Dust-Tight and Easy to Clean
During development of the FE CPS, the focus was on operator safety. All process units are designed to be dust-tight. Additional protection is provided by the enclosed design of the system, including negative pressure in the process chamber and sealed glass panels.
Until now, cleaning and retooling have been considered critical steps in continuous systems, as they consist of well over a hundred individual parts. The FE CPS, on the other hand, is designed with far fewer parts and interfaces, and has separate process and technical areas which are easily accessible.
For this purpose, the dosing-mixing unit was divided in such a way that the process parts of the refilling stations, the dosing stations and the mixer specially developed by Fette Compacting are located in the process area. The technical area, which is dust-tight and separate from the process area, houses the drives, the electronics and the cabling, among other things. All components can be easily removed from the process area for cleaning.
Fette Compacting’s proven "TRI.EASY-design" consistently focuses on the user as well as simplicity in terms of operation, changeover and maintenance. At its heart is the human-machine interface (HMI), which provides operators with an overview of all dosing, mixing and tableting parameters. On a single terminal, operators record the entire continuous process — from recipe management, through reporting, events and diagnostics, to process analysis. Intuitive handling of the HMI significantly lowers the qualification threshold for operation.
Integrated Process Analysis
The stability of the continuous process depends primarily on the material properties and the machine and process design. To monitor the quality attributes, the FE CPS has an innovative ePAT (embedded Process Analytical Technology) system with integrated sophisticated sensors. These can be positioned at the outlet of the mixer, at the inlet of the tablet press, at the Fill-O-Matic, and in the process chamber of the tablet press.
The inline measurements with near-infrared spectroscopy (NIRS), directly in the production flow, allow swift reactions in the case of quality deviations and direct monitoring of the production process. n