An automated system (100) for compounding pharmaceutical agents for injection treatment of a patient includes a housing (110) enclosing an interior space； an inventory structure (130) having a plurality of chambers (131) for individually holding one or more pharmaceutical agent—containing single use capsules (102), wherein each capsule has a volume capacity of from about 0.1 to about 10.0 mL liquid； means (140) for selecting capsules in accordance with predetermined pharmaceutical agents contained in said capsules； means (150) for moving the selected capsules to a processing area； means (165,166) for sequentially transferring a controlled quantity of the predetermined pharmaceutical agent with direct fluid communication from each selected capsule to a product container under positive or negative pressure； and means (151) for automatically discarding spent capsules from which the pharmaceutical agents have been removed after a single use.
