An apparatus for delivering a powdered agent into a subject's body may include a first passage for receiving a pressurized gas. The apparatus also may include a container housing a powdered agent. The container may be in fluid connection with the first passage. At least a portion of the pressurized gas is introduced into the powdered agent in the container to fluidize the powdered agent. The apparatus also may include a second passage for receiving the powdered agent from the container. In a first configuration of the apparatus, the second passage may not be in fluid connection with the container. In a second configuration of the apparatus, the second passage may be in fluid connection with the container. The apparatus may be configured to transition between the first configuration and the second configuration.