The device has an internal receptacle of variable volume provided in a form or shape of a pouch or flexible container. The receptacle contains a fluid e.g. medicinal fluid, under pressure to be delivered and equipped with an actuator (C) for permitting to open a valve. The actuator has a mounting cup (M) with a circular external edge or rim (M1). A wall of receptacle (1) is made of polyethyleneterephthalate (PET) and part of cylindrical extension (E2) is made of a material resistant.
