A medicament preparation system includes a water purification module and a medicament proportioning module that is interoperable with a replaceable fluid circuit. The fluid circuit includes a purified water inlet, a product medicament outlet, and a plurality of pumping tube segments. At least a first concentrate container is connected by at least a portion of the fluid circuit to the product medicament output and a first concentration measurement sensor station is positioned in a flow path. A controller is programmed to calculate iteratively a concentration of a first concentrate from the first concentrate container and the purified water from a signal generated by the first concentration measurement sensor station and to regulate one or both of a first pumping actuator engaged with the first pumping tube segment and a second pumping actuator engaged with the second pumping tube segment, responsively to the concentration of the first concentrate and water.