title: Transforming powder mechanical properties by core/shell structure: compressible sand.
abstract: Some active pharmaceutical ingredients possess poor mechanical properties and are not suitable for tableting. Using fine sand (silicon dioxide), we show that a core/shell structure, where a core particle (sand) is coated with a thin layer of polyvinylpyrrolidone (PVP), can profoundly improve powder compaction properties. Sand coated with 5% PVP could be compressed into intact tablets. Under a given compaction pressure, tablet tensile strength increases dramatically with the amount of coating. This is in sharp contrast to poor compaction properties of physical mixtures, where intact tablets cannot be made when PVP content is 20% or less. The profoundly improved tabletability of core/shell particles is attributed to the formation of a continuous three-dimensional bonding network in the tablet.
authors.affiliation: Pharmaceutical Materials Science and Engineering Laboratory, Department of Pharmaceutics, College of Pharmacy, University of Minnesota, 9-127B Weaver-Densford Hall, 308 Harvard street S.E., Minneapolis, Minnesota 55455, USA.
authors.forename: Limin
authors.initials: L
authors.lastname: Shi
authors.forename: Changquan Calvin
authors.initials: CC
authors.lastname: Sun
mesh_terms: D004339:Drug Compounding / Q000379:methods; D011205:Povidone / Q000737:chemistry*; D011208:Powders / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D013607:Tablets / Q000737:chemistry; D013718:Tensile Strength
chemical_list: D011208:Powders; D013607:Tablets; D012822:Silicon Dioxide; D011205:Povidone