Abstract: Provided is a drug injector adapter configured to be attachable to and detachable from a needleless drug injector, the drug injector adapter which comprises a fixing portion that is inserted and fixed in a position where a nozzle of the drug injector was removed, a coupling portion having a structure for coupling a needle to an opposite side of the fixing portion and a delivery flow passage configured to deliver drugs delivered from the drug injector to the needle in a state in which the drug injector, the needle, and the drug injector adapter are coupled to each other.

Abstract: The present invention provides a microjet drug injection device equipped with a backflow prevention valve, the microjet drug injection device comprising an upper housing, a lower housing, a partition, and the backflow prevention valve provided with a slit through which a drug passes at a lower end and allowing the drug to move only towards an injection nozzle.

Abstract: A needleless syringe having a multi-nozzle and a manufacturing method therefor are proposed. The needleless syringe injects a drug solution through an injection nozzle by expanding a pressure-generating liquid by means of energy generated from a pressure-generating unit, wherein precise branch channels are stably formed so as to inject drugs into a plurality of parts by using multiple injection nozzles. Further, the present disclosure has advantages in that: one energy-generating unit is used and thus nozzles can be densely arranged with a small distance therebetween; when several injections into an affected part are needed, the treatment time can be shortened using multiple injection nozzles; and an inner chamber is inserted into and coupled to or is insert injection-molded in an outer chamber so that more stable and precise branch channels can be formed, and thus multiple drugs can be stably injected into an affected part through multiple injection nozzles.

Abstract: The present invention provides a microjet drug injection device equipped with a backflow prevention valve, the microjet drug injection device comprising an upper housing, a lower housing, a compartment, and a backflow prevention valve.