Preliminary Investigation on the Effect of Production Parameters on the Strength of Large Tablets

Abstract

A case study of large tablet manufacturing in the chemical industry is presented. Since the tablets are much larger than the usual scale in the pharmaceutical industry, common practice that was developed mainly for pharmaceutical tablets could not be applied directly. Customer complaints concerning damaged tablets were the reason for this comprehensive study, which was aimed first at evaluating a testing method for process control, then to provide some hints for stabilizing the manufacturing process and for producing stronger tablets. Three test methods were evaluated: measuring compression and tension crush strengths and wear tests in a rotating drum. It was shown that the wear test provides sufficient results faster and easier than the other methods. By testing hundreds of tablets, produced in various batches, production parameters such as granule aging, surrounding humidity, tableting pressure and tablet aging were evaluated in order to provide stronger tablets. The strongest tablets were achieved by using fresh granules at very high humidity and compacting pressure and by allowing the tablets to age for at least 2 weeks.

Fatigue Analysis of Particle Attrition in a Rotating Drum

“…Kalman and Goder [8] showed that rotating drum tests could be considered as an example of fatigue and are comparable to the attrition that takes place during pneumatic conveying. Another study by Kalman et al [9] showed that rotating drum tests of 1-in tablets are comparable to compression and tensile strength measurements. In this work we investigated the breakage behavior of various materials when they were subjected to repeated impact loads in a rotating drum.…”

Particle Breakage and Attrition

“…However, Kalman et a!. [ 17] showed that the two stresses are correlated for large tablets (2.5 em in diameter).…”