Tooling as a Factor in Tablet Weight Variation and Control

The importance of punch length uniformity to the control of tablet weight variation was demonstrated in a rotary tablet press. An assessment of the weight variation of single-station compression on the multiple-station tablet press was obtained by means of a special isolation technique involving a force-actuated weight control device. Analysis of the relation between punch length and compression force pointed to the uncertainty of the relationship between tablet weight and compression force when variations of upper and lower punch lengths are considered. Control of tablet weight based on compression force signal suffers from this uncertainty, as demonstrated by experimental data.