The direct compression (DC) technology is increasingly popular in the manufacture of tablets due to its efficiency and economy. However, its use in the production of Traditional Chinese Medicine (TCM) tablets is often limited owing to poor powder flow and compaction properties of TCM powders. In this work, we aimed at improving properties of powders used in Fufang Danshen tablet, a popular TCM for treating angina pectoris, by particle surface engineering. Both the active ingredients (Danshen root, Notoginseng, and Borneol) and formulated Danshen mixture exhibit flowability too poor to be processed directly on a high speed tablet press. By dry coating with 1% silica nanoparticles, the flowability, tabletability, and fillability of these powders were adequately improved to be suitable for DC. (c) 2013 Elsevier B.V. All rights reserved.