Devices for injection and dosing

Abstract

Skin can be treated by piercing skin with a plurality of needles of an injection device and ejecting a dose of fluid therethrough. The device can include a housing, a plunger disposed in the housing, a cartridge disposed in the housing, and one or more dosing chambers. The plurality of needles can be coupled to the housing and be in fluid communication with the cartridge. Advancement of the plunger can cause a dose of fluid to be ejected from the plurality of needles.

1 . (canceled) 
     
     
         2 . A method of treating skin comprising:
 piercing skin with a plurality of needles of an injection device, the device comprising a housing, a plunger, a cartridge disposed within the housing, and a plurality of dosing chambers providing fluid communication between the cartridge and the plurality of needles to provide a dose of fluid to the plurality of needles; and   actuating the plunger to distally advance the plunger relative to the cartridge to move the dose of fluid through the plurality of dosing chambers to be ejected from the plurality of dosing chambers into lumens of the plurality of needles.   
     
     
         3 . The method of  claim 2 , wherein the injection device further comprises a trigger extending along a longitudinal axis of the housing and the plurality of needles are positioned adjacent to a distal end portion of the housing, and wherein the piercing comprises radially compressing the trigger. 
     
     
         4 . The method of  claim 3 , wherein the radially compressing the trigger causes the device to move the plurality of needles from a retracted position to an extended position relative to the housing in which the needles extend longitudinally beyond the distal end portion of the housing to penetrate the skin. 
     
     
         5 . The method of  claim 4 , further comprising releasing the trigger to permit the plurality of dosing chambers to be refilled with an additional dose of fluid. 
     
     
         6 . The method of  claim 2 , further comprising contacting the skin with a distal end portion the injection device prior to piercing skin with the plurality of needles. 
     
     
         7 . The method of  claim 2 , wherein the actuating the plunger comprises manually actuating the plunger. 
     
     
         8 . The method of  claim 2 , wherein the piercing skin comprises delivering doses to portions of skin spaced apart by a distance in a range of 5 mm and 20 mm. 
     
     
         9 . The method of  claim 8 , wherein the piercing skin comprises delivering doses to portions of skin spaced apart by 10 mm. 
     
     
         10 . The method of  claim 8 , wherein the piercing skin comprises delivering doses to portions of skin spaced apart by 15 mm. 
     
     
         11 . The method of  claim 2 , wherein the dose is between about 10 μl to 2 ml. 
     
     
         12 . The method of  claim 11 , wherein the dose is between about 20 μl and 1 ml. 
     
     
         13 . The method of  claim 12 , wherein the dose is about 40 μl. 
     
     
         14 . The method of  claim 2 , wherein the dose delivered is between about 5 μl and 50 μl per needle. 
     
     
         15 . The method of  claim 14 , wherein the dose delivered is about 10 μl per needle. 
     
     
         16 . A method of treating skin comprising:
 placing a distal end portion of a handheld device into direct contact with skin to be treated, the device including an elongate housing having a dosing cartridge disposed therein, a trigger extending along a longitudinal axis of the housing, a plurality of dosing chambers, and a plurality of needles in fluid communication with the plurality of dosing chambers and positioned adjacent to a distal end portion of the housing;   moving the plurality of needles from a retracted position to an extended position in which the plurality of needles extend longitudinally beyond the distal end portion of the housing to penetrate the skin; and   distally advancing a plunger relative to the dosing cartridge disposed within the housing to cause a dose of composition contained in each of the plurality of dosing chambers to be delivered into a portion of the skin through the plurality of needles, substantially simultaneously, while in the extended position.   
     
     
         17 . The method of  claim 16 , wherein the dose is between about 10 μl to about 2 ml. 
     
     
         18 . The method of  claim 17 , wherein the dose is between about 20 μl about 1 ml. 
     
     
         19 . The method of  claim 18 , wherein the dose is about 40 μl. 
     
     
         20 . The method of  claim 16 , wherein the dose delivered is between about 5 μl and 50 μl per needle. 
     
     
         21 . The method of  claim 16 , wherein the dose delivered is about 10 μl per needle.