[learn_more caption=”Dr. Pingjun Tang”] Dr. Pingjun Tang is a Senior Scientist in pharmaceutical development at Vertex Pharmaceuticals Inc. in Boston, MA., where he is responsible for powder material mechanical property characterization and application in formulation and process development. He received his Ph.D. at the Pennsylvania State University in 2004. His Ph.D. research was focused on particulate material mechanics including powder flow, segregation, and compaction. He was the founder of the Vertex Compaction Simulator Lab.[/learn_more]

An approach to performing a comprehensive study of important mechanical properties of pharmaceutical materials in a materials‐sparing framework is introduced. The evaluation focuses on coupling precise in‐die measurements, performed with an instrumented die on a compaction simulator, with conventional out‐of‐die breaking tests on the same specimens. A second set of compression experiments is executed using a split die. These data provide a comparative approach to evaluating the impact that die wall / powder interactions during tableting may have on the tensile strength of the final compact. The ultimate data set contains a rich spectrum of material properties which provide insight into multiple aspects powder compression behavior. Approximately ten different mechanical parameters may be derived from these experiments, but the result is a multi‐dimensional, complex analysis space that can be cumbersome for making critical decisions in early stages of development. A simplified model, focusing principally on compact tensile strength and residual die wall stresses measured during compact decompression, is presented as an effective two‐dimensional summary of a more expansive understanding. These parameters may be able to serve as the basis for a simplified classification system of mechanical properties that can assist in important aspects of excipient selection and formulation design. This system is envisioned as an analog to the well‐known Biopharmaceutical Classification System (BCS), and can provide a framework for targeted approaches to robust product development along similar lines.