The present invention relates to a drug delivery device comprising,a reservoir for containing a product, said reservoir having a distally projecting end-piece having a longitudinal axis A and defining a channel providing a passageway for the transfer of the product from the reservoir,an adaptor having a collar engageable with said end-piece,securing means for blocking said collar in the distal direction with respect to said end-piece once said collar is engaged around said end-piece,anti-rotation means for preventing the rotation of said collar with respect to said end-piece around said longitudinal axis A under the effect of a turning torque applied to said collar once said collar is engaged around said end-piece,deactivating means for neutralizing said anti-rotation means once said turning torque has reached a predetermined value, thereby allowing the rotation of said collar with respect to said end. The invention also relates to such an adaptor.
