Studies on Impact Strength of Tablets. III. Impact Load Strength of Tablets

In order to estimate the impact strength of tablets reasonably, load impact tests and static load tests were carried out using the Konsistometer. The impact force for 50% tablet breaking (F50) and the static load for 50% tablet breaking (L50) were obtained from the values of the impact acceleration of the load or the static load, and were compared with the tablet hardness which is regarded as the static compression breaking strength. Deformation of tablets was also examined from the viscoelastic considerations. From the results of these experiments, the following conclusions were obtained. 1) The values of F50 and L50 were directly proportional to the values of hardness. This means that each of these three indices is similar measure of the compression breaking strength, but the values of L50 were 5-6 times greater than those of F50. 2) The breaking deformation (Db) of lactose/starch tablets was approximately constant, regardless of the compaction pressure for tableting or the hardness of tablets. On the other hand, the Db values of crystalline cellulose tablets increased with decreasing compaction pressure. 3) WEO was directly proportional to the hardness for each kind of tablets. Crystalline cellulose tablets which have higher values of Db and total work for tablets breaking deformation (Wb) gave higher values of WEO than those for lactose/starch tablets.