A syringe for mixing and ejecting an active pharmaceutical ingredient is disclosed. The syringe is designed in such a manner that it is ensured that substantially all of the mixed drug is ejected, and in such a manner that an active pharmaceutical ingredient can be lyophilized directly into the syringe. The syringe comprises a syringe body, a first plunger arranged movably inside the syringe body and a second plunger arranged movably inside the first plunger. In one aspect the second plunger comprises a first plunger part and a second plunger part, and the first and second plunger parts are adapted to cooperate to collapse the cavity of the first plunger. In a second aspect the cavity of the first plunger has a first diameter at a distal end and a second diameter at a proximal end, the first diameter being smaller than the second diameter.