Injector apparatus and method for drug delivery

A system for injecting a therapeutic agent into an ocular implant, the ocular implant being at least partially implanted in an eye, the system comprising:

• a cartridge configured to couple to a syringe;
• and
• a needle coupled to the cartridge defining an injection lumen and an outlet lumen fixed relative to one another, wherein the injection lumen is longer than the outlet lumen such that an opening from the injection lumen is positioned distal to an opening into the outlet lumen,
• wherein application of positive pressure into the injection lumen injects a therapeutic agent into an ocular implant through the injection lumen and displaces pre-existing fluid in the ocular implant through the outlet lumen into the cartridge, and
• wherein the outlet lumen includes a restriction structure configured to resist flow into the outlet lumen such that a portion of the therapeutic agent injected through the injection lumen passes as a bolus through the ocular implant and into the eye.

An injector for injecting a therapeutic agent into an ocular implant at least partially implanted in an eye, the injector comprising:

• an injection lumen having a first opening, the injection lumen configured to provide a pathway for injecting a therapeutic agent from the injection lumen through the first opening into the ocular implant using positive pressure applied through the injection lumen;
• an outlet lumen configured to provide a pathway through which a first amount of pre-existing fluid in the ocular implant exits the ocular implant as therapeutic agent is injected into the ocular implant through the first opening from the injection lumen, wherein the injection lumen is in a fixed position relative to the outlet lumen such that the first opening from the injection lumen is located distal to the outlet lumen;
• and
• a receiver chamber fluidly coupled to the outlet lumen, wherein injection of the therapeutic agent into the ocular implant via the injection lumen through the distal opening upon application of the positive pressure through the injection lumen displaces the first amount of pre-existing fluid in the ocular implant into the receiver chamber via the outlet lumen.