In this-the needle hub of syringe will get retracted back in syringe barrel. The needle hub will attach itself to upper part of barrel ,the needle hub is made of breakable Plastics material. Needle hub has two side wings which attach it to the barrel of syringe, when the drug from syringe moves out of syringe barrel ,the upper part of plunger rod which pushes the drug out of barrel when push upwards against the needle hub base ,the base of needle hub will transmit the pressure to side wings of needle hub which are attach to barrel of syringe. As these side wings made of breakable plastics ,it will get break at weakest point of side wing ,which will lead the needle hub getting retracted back in syringe barrel.
