“85% of punch and die problems can be traced back to poor handling and aftercare procedures.”
This surprising figure highlights the importance of why correct maintenance procedures are integral to obtaining the maximum tooling life to mass-produce quality tablets quickly and in the most cost-effective way.
Tablet compression tools are often viewed as consumable items. Though they can be easily replaced, they should never be viewed as disposable. The “throw-away” approach is a mistake that will directly affect production.
Correctly maintaining tablet tooling and ensuring everything is in good working condition will not only reduce tablet press downtime, but it will also minimize common compression problems like sticking and picking. Regular maintenance also increases the lifespan of the tooling, thus retaining the value and productivity of each set of punches and dies.
Stepping up Maintenance Procedures
All tablet manufacturers should implement certain tried-and-tested processes as standard operating procedures to ensure productivity per punch can be maximized more effectively to meet high-capacity manufacturing requirements.
A program of professionally planned and consistent maintenance procedures like the I Holland PharmaCare® 7 Steps will help in maintaining and storing punches and dies correctly so tooling is clean, serviceable, and within specification when required for production (see Figure 1).
The first and most critical step is to clean the tooling. Removal of dirt, lubricant, and product contamination not only prevents cross-contamination, but it also increases the accuracy of tooling inspection and assessment.
Cleaning should take place after every campaign but, for particularly challenging formulations, tooling may need to be cleaned mid-campaign. This minimizes potential production issues like sticking, which is caused by product adhering to the surface of the punch tip. This step also uncovers any damage to punch tip edges like nicks and bruises, which can cause burrs and occasionally chipping.
An ultrasonic cleaner is the most efficient and effective method to clean both coated and uncoated tooling (Figure 2). It is important to clean all equipment, not just punches and dies. Also, ensure die table segments are cleaned using an efficient and repeatable process like the I Holland Segment Cleaner (Figure 3). Equipped with a specially designed fixture to prevent scratching and damage, it holds the segment safely and securely within the tank and leaves the bores unobstructed to ensure effective cleaning of the entire segment.
The next important step is to assess the tooling, checking its condition and suitability to produce tablets of sufficient quality and to prevent tablet press damage.
Punches and dies should be digitally inspected to establish if the tablet production process is running well. Close-up inspection of the punch tips and cups, die bores, embossing, and land will help to identify defects and wear.
Tooling repair should take place after assessment. This will recondition the surface finish of uncoated punches and rectify minor damage to the tooling before further maintenance steps take place.
Minor damage and corrosion can be repaired using a motorized chuck with double-ended polishing motors used in conjunction with abrasive polishing accessories. It is important to remember that repair to punches and dies should only be carried out when only necessary and by trained technicians to ensure that the tooling does not exceed tolerance limits.
Step 4 is to measure the tooling, which is crucial after any repair. Critical tooling dimensions must be maintained within an acceptable range for accuracy and quality throughout the manufacturing process. Even if a repair has not been necessary, measuring should be carried out at regular intervals to check for natural wear during the compaction process.
Polishing is the next step in the process. Frequent and controlled light polishing will ensure the tools are maintained to a smooth finish, helping to maximize tooling life. An automated polishing regimen is preferable due to the controlled and repeatable process.
Next in the process is to lubricate the tooling. Lubrication is important to protect, preserve, and aid the smooth operation of continuous press tooling operations. A non-toxic, FDA-compliant oil or grease that offers machine component protection and lubrication performance with a wide temperature range is recommended to ensure it can be used in all equipment.
The final step is proper storage. Transport and keep tooling in specially designed storage containers to reduce the likelihood of damage. The tooling must be separated to ensure it avoids contact with other punches and prevents deterioration.
Application of the PharmaCare 7 Step Process will have a direct impact on the reduction of many common tablet and tooling problems, resulting in a better quality tablet, and can provide a direct cost saving. However, if each step is not performed correctly the processes are inefficient.
Technicians should be proficient in all areas of tablet compaction, including maintenance procedures, to ultimately improve productivity and enhance the end product.
E-learning provides an economical training solution that results in optimized tablet production (Figure 4). Online learning programs can combine comprehensive and flexible courses in a wide variety of disciplines and is an important method for bringing operators in line with the procedures quickly.
By ensuring key training in procedures like tool maintenance is achieved, tablet manufacturers are helping to make processes more effective and proficient, therefore facilitating increased output and efficiency.
Andy Dumelow is the head of technical sales for Europe, the Middle East, Africa and North America. He has been at I Holland for 20 years and held several technical and sales roles, including PharmaCare Product Manager. He was also instrumental in the 7?Step concept, as well as the launch of our successful I Holland tool management system. www.iholland.co.uk