Chapter 22 The strength of pharmaceutical tablets

Publisher Summary This chapter discusses issues related to pharmaceutical tablet strength. The strength of flat and curved-faced tablets and other characterization methods, such as bending tests are presented in the chapter. Tablets are produced by die compaction, which consists of filling a die with powder, compression between two rigid punches and ejection from the die. The strength of the tablets is dependent on the state of densification of the powder, which is given by the applied force. The resulting tablet is subject to bulk handling and other post-compaction operations during which it must maintain mechanical integrity. In industrial practice, the most commonly applied strength measurement for a compact is the diametrical compression test. The test is simple and easy to perform and has been widely used to determine the tensile strength of a variety of brittle materials such as concrete, coal briquettes, gypsum, and lactose tablets. The mechanical and bioavailability properties of tablets are dependent not only on the composition of the powder blend but also on the process parameters during compaction, which are also defined in the chapter.