An exemplary pharmaceutical compounding system and device for mixing materials from at least two distinct material sources can include a transfer set and junction structure that has a junction body, a first inlet port located at a first portion of the junction body, a second inlet port located at a second portion of the junction body, and an outlet port located at a third portion of the junction body. The junction structure can be configured to mix fluid received from both the first inlet port and second inlet port and to deliver the fluid to the outlet port. The junction structure can also include attachment structure located on the junction body and configured to attach the junction structure to the housing of the compounding device at a location downstream of a pump system.