Robotic injection devices represent a significant advancement in medical technology, aimed at improving efficiency and accuracy of drug delivery. By utilizing advanced mechanisms, healthcare professionals can administer treatments with greater ease, thereby enhancing patient comfort and compliance during medical procedures. In this paper, an injection device attached to a robotic arm has been designed for administering medications into a human body. It comprises a syringe attached to a cylinder and a piston mechanism operated using a pneumatic power source. Design of the injection device is generated using a CAD software. Motion capabilities of the device are validated using a simulation study.