The challenge

The most common issues encountered are machine downtime (this could be associated with powders sticking to die surfaces or tablet “capping” issues for example) and poor product performance (poor disintegration, high friability, variable strengths etc.). These issues are common to a wide variety of tablet shapes, sizes and chemical makeups across many industrial sectors. It is for this reason that Lucideon’s ability to take a generic, non-sector specific approach towards teasing out route causes is sought. The approach is based on understanding key raw material and end-product properties and the process variables that link them.

What we delivered

The final powder delivered to dies for tablet pressing often comprises a blend of individual powders. These can simply be dry mixed together or pre-granulated with or without a liquid phase. In either case, variations in the size and shape of the individual starting powders can compromise the quality of die filling and pressing and, in turn, the quality of the final tablet. Knowledge of the properties in the overall powder blend is not sufficient to determine the cause of poor performance at the pressing stage or in the final product.

For clients able to provide retrospective data on:

1. Batch to batch variations in the shape and size distribution of each individual powder
2. The specific powder combinations used in different tablet batches and
3. The performance of tablets from each batch

Lucideon can provide a useful initial investigative phase. Specifically, Lucideon applies retrospective Factorial Experimental Design (FED) to tease out information on which of the individual powders are most likely to cause difficulties. As well as identifying the culprit powders, FED will provide guidance on how the size of the powder can be changed to give better pressed tablets.

Where this initial “retrospective” FED phase fails to deliver sufficient control, a second phase can be initiated where contrived experiments (featuring key raw material powders milled to “fine”, “medium” and “coarse” size) are undertaken either on factory or in pilot-scale / laboratory trials.

Value to the client

FED provides guidance on specifying tighter “upper” and “lower” limits for particle size in each component powder. By working with powder suppliers to achieve better control, the client is then rewarded with higher yields, less wastage and faster order delivery (this last is achieved through reduced machine downtime).