| 摘要 |
Superficially porous macroparticles of improved characteristics are formed from an impervious core having a diameter in the range of about 5 to about 500 microns, at least two monolayers of like microparticles adhered to the core, each microparticle having an average diameter in the range of about 0.005 to about 1.0 micron, and at least two monolayers of like ultramicroparticles adhered to the surface of the microparticles, each ultramicroparticle having a diameter in the range of about 1.0 to about 15 millimicrons. |
