It is provided an arrangement (100, 200, 300) for administering a predetermined amount of a substance (110) into an organism, the arrangement comprising: a member (129, 229, 329) adapted to provide information indicative of a tissue resistance against flow of a fluid (109) containing the substance (110) upon administration into the tissue (320)； a controller (131, 231, 331) adapted to adjust an administration characteristic of the fluid based on the information such as to achieve an intended absorption rate of the substance (110).
