A device for delivering a drug depot into a patient via a cannula is provided. The device includes a housing with a coupling mechanism. A drug cartridge is positioned within the housing and includes a cartridge depot channel having an occluding device that includes a ramp and a plateau. The occluding device occludes the cartridge depot channel to prevent the drug depot from moving beyond the occluding device without force applied to the drug depot sufficient to deflect the occluding device an amount to allow the drug depot to move beyond the occluding device. The drug cartridge includes an alignment boss with an end channel coaxial with the cartridge depot channel. A push rod is slidably receivable in the housing and the drug cartridge to move the drug depot beyond the occluding device, into the cartridge depot channel, through the cannula and into the patient.