in fig1 the needle is shown generically as numeral 1 and is connected to a conventional hypodermic syringe 2 . syringe 2 has a luer - lock collar 3 threadingly engaged with the needle 1 . a cannula 4 of a needle ( shown in dotted line ) extends through a closure of vial 5 . as shown in the broken away section at the bottom of fig1 this vial contains a lyophilized powder drug 6 , as well as a large portion of air 7 . during the filling operation , shown in fig1 a plunger 8 of syringe 2 is manually moved in a downward direction to turbulently spray liquid in a lateral direction from side ports 9 and 10 of cannula 4 . the precise details of the special needle are better shown in the enlarged view of fig2 . here the generic needle includes a cannula 4 and a hub 11 . hub 11 is designed to sealingly engage with the luer - lock collar 3 and tapered luer adapter ( not shown ) of syringe 2 . as shown in fig2 the cannula has a central passage 12 that extends to a forward end 13 . adjacent forward end 13 is lateral side port 10 . because of the 90 ° rotation from the view shown in fig1 side port 10 appears to the rear of the viewer rather than to the right of the viewer . along a right side of fig2 is a vent groove 14 extending from a forward end 15 to a rearward end 16 . the forward end 15 of groove 14 lies adjacent side port 10 so that a small protrusion of the needle &# 39 ; s forward end beyond the inner surface of resilient rubber stopper 17 exposes the vial &# 39 ; s interior to both a liquid discharge port and an air vent . the forward end portion of cannula 4 is closed and has a generally conical forward tip 18 that terminates in a solid puncture point 19 . this tip configuration substantially eliminates the coring problem with previous openended bevel cut hypodermic needles that were forced through rubber stoppers . near a juncture of the cannula 4 and hub 11 are a series of wings , two of which are shown at 20 and 21 . these wings respectively have abutting surfaces 22 and 23 that engage an upper surface of the vial stopper . this limits the insertion distance of the needle , so a portion of the vent groove 14 adjacent its rear end 16 is always exposed to the atmosphere . in the second embodiment of the invention shown in fig3 the needle is identical to that shown in fig2 with the exception of the optional filter 24 in the fig3 embodiment . this filter 24 can act to strain out particulate matter from liquid within the syringe tube , and acts as an additional safety feature . the bottom end of the needle of fig3 has this section taken at a 90 ° rotation from that section of fig2 . hence , side ports 25 and 26 of the fig3 embodiment correspond to the side ports 9 and 10 of the fig1 embodiment . the arrows show the direction of lateral liquid flow from the two side ports . the relationship of the two side ports 25 and 26 and their relationship to vent groove 27 in the fig3 embodiment is best shown in fig4 . the vent groove and side ports are circumferentially spaced 90 ° apart to prevent air from being sucked into the needle during drug aspiration . bordering the edges of groove 27 are generally triangular segments 28 and 29 which extend longitudinally along the cannula . this gives the circumferential shape of the cannula a somewhat teardrop configuration . by use of the triangular segments 28 and 29 , groove 27 does not interfere with the structural rigidity of the cannula . with this configuration , the cannula &# 39 ; s external diameter is kept to a minimum to decrease drag when puncturing the vial &# 39 ; s rubber stopper . in the foregoing description the needle has been described as an implement for injecting liquid into a vial for mixing with dry lyophilized drugs . if desired , a separate sterilized needle of the same configuration shown in fig2 or 3 can be used to withdraw the liquid dissolved medicament from the vial . in such situation , the filter 24 of fig3 would act to prevent particulate matter within the vial , from being sucked into the syringe . when the filtered needle to fig3 is used to inject diluent into a vial as in fig1 the needle also filters the diluent entering the vial . the needle of this invention works very well when the cannula and hub are injection molded as a one - piece unit of transparent thermoplastic , such as polycarbonate . in this needle it has been found that a groove that is from 0 . 005 to 0 . 015 inch ( 0 . 127 to 0 . 381 millimeters ) wide and is from 0 . 010 to 0 . 030 inch ( 0 . 254 to 0 . 762 millimeters ) deep . the distance from the side port to the abutting surfaces 22 , 23 , of wings 20 , 21 is preferably 0 . 300 to 0 . 500 inch ( 7 . 62 to 12 . 7 millimeters ). the needle as described above and with the dimensions specified work exceptionally well for rapidly injecting liquid into a vial without pressure buildup and without stopper coring . although the needle can be used with an inverted ( stopper downward ) vial to extract liquid , it has been noted that occasionally some liquid seepage will pass through the air vent groove . in the foregoing description , specific embodiments have been used to describe the invention . however , it is understood by those skilled in the art that certain modifications can be made to these embodiments without departing from the spirit and scope of the invention .
a thermoplastic needle for injecting sterile liquid into a vial with lateral turbulent motion while air from such vial escapes through a special vent groove on the needle . the needle also has spaced stop wings adjacent a rear portion of the vent groove to prevent overinsertion and occlusion of the vent groove .