Seven Steps to Solving Tabletting and Tooling Problems—Step 1: Clean

Many factors can contribute to tablet manufacturing problems. Tablet tooling failures are generally the result of one, or a combination of issues. In this series, we will discuss some of the difficulties and how to avoid them with simple steps that will help to resolve these including:

• Difficult product/granule

• Inappropriate tablet design

• Incorrect tablet press set up and operation

• Inadequate tablet press maintenance

• Poor condition of tablet tooling.

I Holland has developed the PharmaCare seven-step process, a logical, planned, and professional approach to tooling maintenance, measuring, and storage that has been adopted by many companies around the world as a standard operating procedure (SOP). Each step-clean, assess, repair, measure, polish, lubricate, and store-has been designed to help users extract the maximum life from tablet tooling. It provides a consistent approach to tooling maintenance and aids production at all times by sitting seamlessly alongside your tablet production processes. Having a coordinated tooling SOP ensures punches & dies are ready for production, with the assurance that they are clean, un-damaged, and within specification.

Step 1: CLEAN

Step 1, Clean, is the most critical part of the PharmaCare seven-step process. Punch and die cleaning is essential for the removal of residue and to avoid product contamination and potential production issues, such as sticking and picking, caused by old product adhering to the surface of the punch tip. Cleaning also allows for an accurate assessment of tooling condition during further processes within any maintenance schedule. If cleaning is not carried out effectively, it will have a knock on effect on the other steps in the process. For example, if punches are not sufficiently clean, this will make visual assessment of the punch tips and die bores for signs of wear, damage, or corrosion more difficult. Repair work to be undertaken and measurements such as working length may also be inaccurate.

When tooling is removed from the tablet press, it should be thoroughly cleaned to remove any oil or product residue, especially from difficult to reach areas such as embossing and keyways etc. Equipment used for this process would include ultrasonic cleaning and automated washing processes. However, it is essential that the process does not cause corrosion of the tooling material and to that end, a corrosion inhibitor should be used.

This step can be used to highlight damage to punch tip edges. Punch tip edges are very delicate and damage may occur in the form of nicks and bruises causing burrs and occasionally chipping. These defects can lead to more serious failures such as punch tip breakage. Experience tells us that approximately 80% of damage to punches and dies is usually caused accidentally when handling the punches through the production and tool care processes. Examples of where this can happen include, when loading or unloading the tools in the tablet press, during transportation of the tooling, during storage, or whilst cleaning or polishing the tools. By adopting Step 1, Clean, of the seven-step process, this type of damage can be identified and by repeating the assessment throughout the process, we may recognise the main causes.

Andy Dumelow is PharmaCare manager at I Holland.