Seven Steps to Solving Tabletting and Tooling Problems---Step 2: Assess

Last week, the importance of adopting a simple PharmaCare seven-step process for punch and die maintenance, to help eliminate a number of potential tablet manufacturing problems and tablet tooling failures was discussed. We looked at optimized cleaning techniques for tablet tooling. As the second part of this series, we look at the importance of “assessing” the punches and dies to check their condition and how this step may help avoid any problems that may occur during tablet manufacture.

Step 2: ASSESS

Punches and dies should be visually inspected to establish if the tablet production process is running well and also to identify whether any tooling maintenance is required. This assessment should also be carried out under magnification, looking for any signs of damage, wear or corrosion on the tooling, and to validate the cleaning process.

By carrying out a visual assessment, it will establish if the production process is working as it should, giving clues to problems with the tablet press or tooling itself. This assessment step will also show if any tooling maintenance is required. Typical equipment that should be used to assess include high magnification lenses and microscopes. I Holland’s iNSPECT, visual camera system is one example of such product. Due to the high mirror finish of tablet tooling, it has been especially developed for the close inspection of punch tips and tablets. Any system that is used should be precise and should give a clear high quality image that can enable identification of any problems.

Physical close up inspection and photography of punch tips and cups, die bores, tablets, embossing, and land will help to identify defects and wear, which in turn will allow for any tooling repair work or replacements to be planned. One such problem that can be identified through this step is head wear. This is where those areas of a punch that are in contact with other parts of the tablet press and are subjected to high speed frictional and compaction forces and are typically prone to wear. An example is the head ‘dwell’ flat, which is in contact with the pre-compression and main compression rollers. If the wear is considered to be premature, then it should be investigated. It may be attributable to various causes, but more commonly it is due to punch tightness and/or poor lubrication. This can be identified during Step 2. Remember that identifying damage off the tablet press is far less costly and time consuming for the tablet manufacturer and far better than letting the tablet press find it.

Andy Dumelow is PharmaCare manager at I Holland.