The Four Steps of Tabletting
A simplified process flow for tabletting is as follows:
This process occurs very quickly and utilises top of the range equipment. The tablet compression machines in our HCMF are coupled through a control console to an in-line WHT (Weight, Hardness and Thickness) sampling unit. Uncoated tablet cores are then passed through de-dusters and metal detectors. The compression machines are double sided and operate at up to almost 4000 tablets per minute.
The control console controls both sides of the compression machine and utilises information from the in-line WHT unit along with the compression machine compaction force. This way, the compression machine’s operating parameters are automatically adjusted to meet a pre-set specification.
It was not always like this in the past, IPC tablet tests from weight thickness and hardness were done manually (usually every hour) and the press stopped for adjustment – some companies still use manual IPC tests and readjust compression machines manually. This slowed down the process considerably and was not as efficient. Additionally, the presses needed to be continually monitored and could not be run in ‘light out’ mode.
For automated compression machines to run effectively there are a number or parameters that needed to be controlled to meet the four basic parts of the process.
Filling requires good powder flow – this is achieved at Consort Medical by a granulation process (spray granulation utilising a fluid bed granulator). This is where the API (Active Pharmaceutical Ingredient) are mixed in a fluid bed granulator whilst being sprayed with a granulation liquid to agglomerate the particles of API powder to form larger granules. These granules are dried to a pre-set moisture content under control of air temperature and flow rate. To achieve even more consistency the granules are graded through a mill before being mixed with powdered diluent and lubricant. This is a validated process so that the granule mass / size / moisture content is repeatable between batches and results in consistent flow properties to fill the compression dies quickly to achieve tablet weight control and compression speeds. Granulation also reduces the effect of segregation of API’s due to particle size segregation effects.
Metering requires good flow of granule together with consistent granule density. Variation in granule density and poor flow will result in variation of tablet weight at a set compression speed and would require the compression turret speed to be reduced to maintain tablet weight in specified tolerance.
Compression requires the formulation and manufacturing process of the granule that easily compresses to produce tablets of the required hardness and correct quality with no defects and to meet dissolution requirements.
Ejection requires the formulation and manufacturing process of the granule that easily compresses to produce tablets of the required hardness and correct quality with no defects and to meet dissolution requirements.
Increased efficiency in tablet compression to meet patient supply
All pharmaceutical companies strive for increased productivity consistent with improving quality, and Consort Medical is no different. To achieve this increased production, it requires modern validated automated compression machines linked to automated in-line testing equipment that feeds back in real time to adjust the compression machine’s parameters. This is only possible with a validated formulation and granulation/mixing process in order to reduce variability to a minimum.
The benefits seen are an increase in efficiency in terms of tablet compression speed with reduced level of manual input to produce tablets of improved consistency and quality. The end effect is the production of an increased quantity of high quality tablets that both meet specification and patient supply.