An exemplary pharmaceutical compounding system and device for mixing materials from at least two distinct material sources can include a valve including a valve housing and a valve structure located within the valve housing. The valve structure can be configured to permit fluid to flow through the valve when in an open position, and can include a gravity wall wherein, when the valve structure is in the open position, fluid moving through the valve structure moves upward against a force of gravity when travelling through the valve and traversing the gravity wall.
