An intradermal injection device comprising a unitary body having an open distal end and a proximal end having a skin engaging surface defined thereon, a reservoir defined between the proximal and distal ends for accommodating a drug substance, and a channel defined at the proximal end of the unitary body and extending through, and distally from, the skin engaging surface to the reservoir. A needle cannula having a sharpened proximal end and a distal end may be provided in the channel. The needle cannula is secured in the channel with the distal end being in communication with the reservoir and the proximal end of the needle cannula extending from the skin engaging surface a distance in the range of about 0.5 mm to 3.0 mm such that the skin engaging surface limits penetration of the proximal end of the needle cannula to the dermis layer of the skin of a patient.