Abstract: A dissolution rate analyzer for determining the solubility of pharmaceutical products. It automatically loads, mixes, and samples the test product; then cleans and dries the test vessel before repeating the process. The analyzer has a plurality of vessels with agitator blades. Each blade has a series of channels and is attached to a hollow shaft which is rotatable and vertically displaceable. The channels in the blades are connected by the hollow shaft with sources of fluid and air. By pumping liquid and air out the channels in the blades, and simultaneously rotating the agitator and moving it up and down, the vessel thoroughly cleans itself. The cleaning liquid is drained off through a valve in the bottom of the test vessel. A magazine connected to a dispenser loads the next sample, fluid is added, and the mixture is agitated before analysis of the next sample begins.