Receptacle and delivery system for drugs delivered by powder inhalation and a method related thereto which provides improved entrainment, deagglomeration and/or aerosolisation of the powder. The receptacle (1) for holding a medicament comprises a cavity provided with a raised ridge (6, 22) which is adapted so that, in use, the airflow (in particular the inlet air or flushing air within the receptacle) is split into two substantially equal parts, e.g. providing first and second reservoirs.