The Dr pen’s sterile cartridge are designed to be disposable and for are for a single-use only, to prevent cross-contamination and infection. The nee/dle tips cannot be be properly decontaminated due to the materials used in the construction of the nee/dle tip cartridge itself. The Dr pen’s design permits the user to change the nee/dle tip cartridge after each use, at a very low consumable cost with each treatment. A low consumable cost, combined with little to no downtime for the user, makes Dr pen an ideal solution.