As a tableting process is moved from one tablet press to another, tablets may change with respect to hardness, friability, disintegration, dissolution and other properties. Although there are many factors which will ultimately determine the speed at which a given product can be run on a tablet press, the primary variables that must be considered are those which affect tablet weight and tablet integrity (i.e., hardness, friability). Tablet weight consistency is inherently linked to the total time the die spends under the feeder, while tablet integrity depends on compression force and the time interval over which compression occurs. Experience has shown that both tablet weight consistency and integrity improve as feed times and compression times (dwell) increases.
Often, the maximum output (in tablets per minute) that can be achieved on a particular press with a given formulation will be limited alone by either tablet weight consistency or integrity. Rarely do both qualities reach their limits simultaneously. Thus, it is important to note which of these two factors will play the more dominant role in determining production output rates. If, for instance, it was discovered in research trials that weight variations due to the characteristics of the formulation were difficult to control at higher speeds and tablet integrity requirements were easily obtained, greater emphasis should be placed on feed times than on dwell times.
The type of tooling used (i.e., “B” or “D”) does not affect feed times, but does play a role in dwell time:
- Dwell Time: Time (in seconds) that the tool is under maximum compression
- Head Flat Diameter: The flat area of the punch head
- RPM: Revolutions per minute
- PCD: Pitch Circle Diameter (the distance on a press turret from the center of one die to the center of the die on the opposite end of the turret)
Therefore, to maintain tablet integrity during SUPAC, it is recommended to match the dwell time from the current tableting process. This is accomplished by adjusting the RPM of the new press using the above formula.
For more information on compression tools from Wilson Tool, please contact our Tooling Technicians or visit wilsontool.com/tablet.
June 24, 2022