A drug preparation kit is disclosed that includes an adapter and a funnel unit. The adapter has a stud section with an in-container side and an out-container side. The stud section of the adapter is dimensioned to tightly fit into an opening of a container. The adapter has an access passage extending from the out-container side to the in-container side through the stud section. The funnel unit has a neck portion dimensioned to tightly fit into the access passage of the adapter. The funnel unit has a degassing channel formation arranged to provide a degassing channel extending from the in-container side of the stud section of the adapter to the out-container side of the stud section of the adapter when the neck portion of the funnel unit is fitted into the access passage of the adapter.
