On predicting the performance of different silicas on key property enhancements of fine APIs, blends, and tablets

Predictive selection of silica size, type (hydrophobic/hydrophilic), and amount is addressed for achieving significant property enhancements of fine active pharmaceutical ingredients (APIs). Four models, Chen's multi-asperity particle-adhesion, total surface energy-based guest-host compatibility, dispersive surface energy-based tablet tensile strength, and stick-bounce-based silica aggregation on coated particles, are invoked. The impact on the bulk properties of four APIs cohesive API powders (∼10 μm) and 40 wt% (wt%) blends of one API, dry-coated at 50% and 100% surface area coverage (SAC) of four nano-silicas (7–20 nm), hydrophobic (R972P), hydrophilic (M5P, A200, A300) is assessed. Significant enhancements in flowability, bulk density, compactability, agglomeration reduction, and dissolution for API or blend are achieved with all silicas. The experimental and model-based outcomes demonstrate that silica performance is impacted by multiple factors, silica size and coating effectiveness being most critical. In conclusion, R972P and A200 at lower 50% SAC present two excellent choices.