Chewability testing in the development of a chewable tablet for hyperphosphatemia.

The official Pharmacopeia does not include a test procedure for the in vitro estimation of the chewability of tablets and publications in the scientific literature on this subject are rare. The purpose of this study was to evaluate a number of different test procedures for assessing chewability, starting from standard breaking force and strength testing and progressing to develop new procedures that simulate the actual chewing action on tablets. A further goal was to apply these test procedures to characterize the chewability of the novel phosphate binder PA21 in comparison with a commercially available phosphate binder chewable tablet product based on lanthanum (Fosrenol®) and a chewable tablet product containing calcium (Calcimagon®) - the latter being used as a standard for its very good chewability.