A mechanistic powder compaction equation for blends

A mechanistic powder compaction equation for binary blends is proposed, extending author's previous single-component framework (Powder Technology 464, (2025) 121285) to predict tablet tensile strength from physical particle properties and two fitting parameters: the corrected contact number c and the brittle property number k. Novel mixing rules are developed for c_mix and k_mix based on three dimensionless quantities: the surface area fraction λ, particle number fraction χ, and weighted surface area fraction ω, which capture the relative contributions of particle size, density, and composition. The model is validated against two binary blend systems: a ductile–ductile blend (Ibuprofen (IBU)–microcrystalline cellulose (MCC)) and a brittle–ductile blend (Mannitol–MCC), spanning six loading levels. Ductile–ductile systems where k=0 for both components is determined by c_mix for blend predictions and captures the nonlinear decay of tensile strength of intermediate IBU blends. Brittle–ductile systems, where one component k≠0 is governed by both c_mix and k_mix capturing the more gradual decline in strength and wider porosity sensitivity at high Mannitol loadings. The novelty of this framework is that it provides quantitative formulation guidance, without having to prepare and test blends, yet can predict that the IBU–MCC system could achieve ∼60% IBU loading while the Mannitol–MCC system could achieve higher, ∼70% Mannitol loading before falling below a 2 MPa tensile strength threshold.