An experimental investigation was carried out to study the mixing performance of a laboratory-scale ResonantAcoustic (R) Mixer (LabRAM). The first part of the study summarizes the results of a fractional factorial design of experiments used to determine the main effects of process parameters (fill level, acceleration, and blending time) on blend homogeneity. Studies were carried out for several blends having various values of particle size, cohesion and concentration of the active pharmaceutical ingredient. The second part of the study describes the LabRAM mixing performance as a function of process parameters (fill level and acceleration) and total blending time. The blend homogeneity was quantified by estimating the relative standard deviation (RSD) for low concentration of active pharmaceutical ingredient (acetaminophen, 3% w/w) and lubricant (magnesium stearate, 1% w/w) blend. Overall, the LabRAM reached the minimum blend homogeneity in as low as 30 s depending on process parameters. The temperature of the final blend increased with fill level, time and acceleration. Resonant acoustic mixing can significantly reduce blending time, making it a good candidate for improving the efficiency of powder mixing processes. (C) 2015 Elsevier B.V. All rights reserved.