The purpose of this article is twofold; firstly, to introduce a new method for characterizing the release of drugs from single agglomerates and, secondly, to use the proposed method to investigate drug release from pellets made of microcrystalline cellulose, containing either sodium chloride or salicylic acid as model drug. The proposed experimental setup utilizes a recirculating flow-through system for the dissolution medium, and uses conductivity measurements to monitor its drug concentration. Pellets of two different porosities are investigated, and two different dissolution-medium flow rates are used. The mean dissolution time was used as a model-independent measure of the overall release rate. Analysis of variance was performed with two levels for each of the three factors drug solubility, pellet porosity, and dissolution-medium flow rate. Drug solubility and pellet porosity had highly significant effects on the drug release (p < 0.001), whereas flow rate had no significant effect. It was also possible to extract physicochemical parameters characterizing the release process (effective diffusion coefficients, drug solubilities and dissolution rates), which in general showed good agreement with expected results. The proposed method yielded single-pellet release data of sufficient quality for meaningful conclusions to be drawn, even though the drug content of each pellet was as low as similar to 30 mu g. (c) 2005 Elsevier Ltd. All rights reserved.