Syringes, kits, and methods for intracutaneous and/or subcutaneous injection of pastes

1. A pre-loaded syringe, said syringe pre-loaded with a paste, comprising:

a syringe body defining a reservoir having an internal first transverse dimension;

a paste disposed within the reservoir, the paste having a volume of between 15 μL and 2000 μL, a stiff consistency, and a solids concentration of greater than 50 mg/mL;

a plunger disposed within the reservoir and configured to be moved to dispense paste from the reservoir;

a Luer fitting disposed on the syringe body and in fluid communication with the reservoir;

a sealing cap disposed on the Luer fitting to seal the reservoir; and

a needle defining a lumen having an internal second transverse dimension, the needle configured to be coupled to the syringe body via the Luer fitting to allow intracutaneous delivery of the paste;

wherein the internal first transverse dimension of the reservoir is 3 to 20 times larger than the internal second transverse dimension of the lumen of the needle; and

wherein the syringe is configured to dispense the paste at a flow rate of greater than 30 μL/s or greater than 65 μL/s under a force applied to the plunger having a magnitude below 50 N.

2. The pre-loaded syringe of claim 1 , wherein the solids concentration of the paste is greater than 100 mg/mL.

3. The pre-loaded syringe of claim 1 , where the first transverse dimension is between 1 and 10 mm.

4. The pre-loaded syringe of claim 1 , where the second transverse dimension is between 0.1 and 0.9 mm.

5. The pre-loaded syringe of claim 1 , where the needle has a size of 18 Gauge, 27 Gauge, 30 Gauge, or smaller.

6. The pre-loaded syringe of claim 1 , where the needle has a length smaller than 50 mm, 40 mm, or 13 mm.

7. The pre-loaded syringe of claim 6 , where the needle has a length of approximately 6 mm.

8. The pre-loaded syringe of claim 1 , where the paste has a volume greater than 50 μL or greater than 100 μL.

9. The pre-loaded syringe of claim 1 , where the paste has a solids concentration of greater than 200 mg/mL.

10. The pre-loaded syringe of claim 9 , where the paste has a solids concentration of between 300 and 500 mg/mL.

11. The pre-loaded syringe of claim 1 , where the paste has a solids content of between 1% and 99%.

12. The pre-loaded syringe of claim 11 , where the paste has a solids content of between 30% and 50%.

13. The pre-loaded syringe of claim 1 , where the paste has a density of between 1.1 and 1.4 g/mL.

14. A kit comprising:

the pre-loaded syringe of claim 1 , where the paste has a solids concentration of greater than 100 mg/mL.

15. A method of intracutaneously injecting a volume of paste comprising:

moving the plunger of the pre-loaded syringe of claim 1 to dispense paste from the reservoir of the syringe through the lumen of the needle of the syringe, where the internal first transverse dimension of the reservoir is between 1 and 10 mm and the internal second transverse dimension is between 0.1 and 0.9 mm;

where the paste has a solids concentration of greater than 100 mg/mL; and

where the paste is dispensed at a flow rate of greater than 30 μL/s as the plunger is moved at a rate of between 2 and 40 mm/s.

16. The pre-loaded syringe of claim 1 , wherein the force applied to the plunger has a magnitude below 25 N.