A cannula for administration of a medicine to a target location includes a tube with at least one nodule disposed along the circumferential surface and spaced at a defined distance from the distal end of the tube. An arrangement for delivery of a medicine to a target location includes the cannula and a pump fluidly coupled to the cannula. The distal end of the cannula may be inserted into a target location until the nodule reaches a surface that limits a depth of penetration before delivery of the medication.