The aim of this paper was to investigate the importance of the core particle - coating material interaction with respect to attrition strength of coated particles. To this end, 5 mu m thick cellulose derivative coatings (methylcellulose, carboxymethylcellulose and hydroxypropylcellulose) have been applied on three different core materials: sodium benzoate (Purox-S), salt crystals and microcrystalline cellulose. Coated particles of 800-1000 mu m were attrition tested during RIT (repeated impacts tests). The results showed that the attrition strength of coatings obtained from the investigated cellulose derivatives is strongly related to the core particle properties (shape, size, particle density, material structure) and to the interaction of the core particles with the coating materials. Generally, it can be concluded that there is no single coating material providing the highest attrition strength on each core particle studied. The RIT data showed that the lowest values for attrition strength were obtained when the coatings were applied on salt particles. On the contrary, using MCC as a core particle resulted in the highest coating strength and no mass losses were obtained even after applying high values of mass specific kinetic energy. Moreover, the research proved that despite the mass losses observed during attrition testing of coated salt and Purox-S particles, the investigated cellulose derivative coatings protect the cores to some extent against breakage as the attrition rate of uncoated salt crystals and Purox-S particles was much higher in comparison with coated particles. (C) 2012 Elsevier B.V. All rights reserved.