A dispensing device (102) is provided to dispense a designated amount of material on every dose delivery operation. The dispensing device (102) includes a thumb pad (202) and a cam drum (204) that is coupled to the thumb pad (202). The thumb pad (202) is configured to be pulled out towards a proximal end (104) of the dispensing device (102) for setting a dose of a material to be dispensed out and to be pushed in towards a distal end (106) of the dispensing device (102) for delivering the dose. The cam drum (204) includes at least one linear cam profile (402) and at least one helical cam profile (404) that are disposed on a surface of the cam drum (204). The thumb pad (202) is configured to ride on the linear cam profile (402) when setting the dose and on the helical cam profile (404) when delivering the dose.