Validation and applications of an expedited tablet friability method

The harmonized monograph on tablet friability test in United States Pharmacopeia (USP), European Pharmacopeia (Pharm. Eur.), and Japanese Pharmacopeia (JP) is designed to assess adequacy of mechanical strength of a batch of tablets. Currently, its potential applications in formulation development have been limited due to the batch requirement that is both labor and material intensive. To this end, we have developed an expedited tablet friability test method, using the existing USP test apparatus. The validity of the expedited friability method is established by showing that the friability data from the expedited method is not statistically different from those from the standard pharmacopeia method using materials of very different mechanical properties, i.e., microcrystalline cellulose and dibasic calcium phosphate dihydrate. Using the expedited friability method, we have shown that the relationship between tablet friability and tablet mechanical strength follows a power law expression. Furthermore, potential applications of this expedited friability test in facilitating systematic and efficient tablet formulation and tooling design are demonstrated with examples.