Abstract: A solution pumping system including a disposable pump cassette is disclosed, with the system configured for efficient and accurate preparation of parenteral admisture solutions. The system includes a pump driver having a reciprocable pump plunger and a plurality of associated valve actuators. The disposable pump cassette of the system is configured for removable positioning in operative association with the pump driver, and includes a positive displacement pump configured for operation by the reciprocable pump plunger. The pump cassette further includes a plurality of liquid inlets, and at least one liquid outlet joined in fluid communication with the inlets. By selective operation of the valve actuators of the pump driver, one or more selected source solutions are drawn through the pump inlets by the positive displacement pump, and directed through the pump outlet to an admixture solution container.