Assessing materials' tablet compaction properties using the Drucker–Prager Cap model

Abstract

Compaction of powders into tablets is the most common method for producing solid dosage forms in the pharmaceutical industry. Despite the frequent use of compaction, the majority of commonly used methods for assessing compaction behavior of pharmaceutical materials are empirical in nature, and are not based on fundamental material properties. This can make it difficult to predict whether a material will fail to compact properly. This work describes the use of a physical model of the compaction process to determine relevant fundamental material properties, which will improve our ability to predict and control compaction problems. The parameters of the Drucker–Prager Cap (DPC) model of 14 materials, including excipients, active compounds and formulations are provided. The function of the DPC parameters with relative density is determined for each material. The material properties were compared at a common relative density of 0.85. Several of the formulations are known to have compaction risks, e.g. low tablet strength, high compaction force, or tablet defects. It is shown that insight into these materials' compaction behavior can be gained by examining these model parameters, as well as the stress distribution required to compact tablets. The development of this method will enable the evaluation of compaction risk using a small amount of material, and minimize the need for larger scale studies.