In the pharmaceutical industry, dissolution testing is a critical step in quality control and a standard method for assessing batch-to-batch consistency of solid oral drug delivery systems, such as tablets. One of the most widely used dissolution test devices is the UPS Apparatus 2 (paddle). At present, dissolution testing remains susceptible to significant error and test failures. Previous studies indicate that poor reproducibility of dissolution testing data and inconsistency of dissolution results can arise from the complex hydrodynamics present in the unbaffled, hemispherical-bottom, agitated vessel that constitute the UPS Apparatus 2. In the present invention, a novel dissolution testing apparatus was constructed in which the impeller was placed off-center with respect to the center point of the vessel bottom. It has been shown that the dissolution profiles in the present invention were not significantly affected by tablet location as confirmed by the value of the factors f1 and f2, which were well within the accepted ranges and did not change appreciably with the tablet location. By contrast, the corresponding dissolution tests for current systems failed these similarity tests. In addition, the flow fields near the vessel bottom were obtained via CFD simulation and were found to be significantly more uniform in e present invention than in the current standard apparatus. The present invention has the potential of becoming a valid alternative to the standard USP dissolution testing apparatuses used for dissolution testing.