Texture and surface feature-mediated striking improvements on multiple direct compaction properties of Zingiberis Rhizoma extracted powder by coprocessing with nano-silica.

The study aims to markedly improve direct compaction (DC) properties of Zingiberis Rhizoma extracted powder (ZR) by modifying its texture and surface properties with nano-silica (NS). A wet coprocessing method was applied to evenly distribute up to 33.3% NS to ZR. To clarify uniqueness of NS, microcrystalline cellulose (MCC), a superior filler-binder in DC, was used as control. Coprocessed particles and physical mixtures (PMs) were comprehensively evaluated for surface features, micromeritic properties, and texture and compacting parameters. Compared to MCC, NS could more significantly modify the texture and surface features of ZR (e.g., hardness, cohesiveness, yield pressure, and nanoscaled surface roughness) via coprocessing, resulting in more striking improvements on multiple DC properties of ZR, including tabletability, flowability, lubricant sensitivity, hygroscopicity, etc. Especially, tensile strength (σt) of coprocessed ZR-NS (1:0.5) tablets was 4.62 and 3.22 times that of ZR and ZR-MCC counterparts pressed at 210 MPa, respectively. Moreover, percolation thresholds of σt enhancement were observed for ZR-NSs, but not for ZR-MCCs. Evaluation by the SeDeM expert system indicated that some ZR-NSs (but no ZR-MCCs) were qualified for DC. Collectively, coprocessing with NS by liquid dispersion appears to be a novel, effective, and pragmatic option for DC of drugs like ZR.