GB1306126A - - Google Patents

Abstract

1306126 Hypodermic syringe J A O'CON NOR 9 Aug 1971 [17 Aug 1970[ 39467/70 Heading A5R [Also in Division Bl] A hypodermic syringe for separately storing two components, e.g. a drug and a diluent, and permitting mixing in the syringe body and dispensing therefrom comprises a syringe barrel 10 with a distal portion 12 to receive a dispensing means, at least two parallel, coextensive channels 17 in the wall of said barrel, a piston 14 slidably mounted within said barrel and of shorter axial length than the axial length of said channels, said piston being able to separate said barrel into two non-communicating chambers, a rupturable hermetic seal 23 of a polymeric material applied to seal the piston to said barrel, said seal being rupturable by rotating said piston, a plunger 16 locked into said piston and extending proximally thereof, a plug 22 at the proximal end of the barrel constructed to permit rotation of at least said plunger in said barrel, a hermetic seal 24 between said plunger and plug, a hermetic seal 25 between said plug and barrel, and at least one of the latter two seals being a rupturable seal of a polymeric material. Operation The syringe is firstly filled by sealing the distal end either by a needle and protective sheath, or by an occlusive cap 26, the sheath and cap being hermetically sealed to the syringe. The component for the forward compartment is then loaded into the syringe through the rear end of the barrel and the piston 14 is then inserted into the barrel either forwardly or rearwardly of the channels. A rupturable hermetic seal 23 is then formed between the piston and the barrel wall. The rearward compartment is then filled with the remaining component and plug 22 is slid forward along the plunger into position just inside the rear opening of the syringe barrel. If a liquid component is to occupy the rear compartment then the compartment is filled followed by insertion of the plunger into the piston, after which the plug 22 is slid into position as before. The joints between the plug and wall of the barrel, and between the plug and the plunger are also hermetically sealed. The syringe is operated by firstly gripping the barrel 10 and plunger 16 and twisting the plunger in a clockwise direction in order to rupture the seal 23 maintaining the piston in the storage position. Depending upon the construction of the plunger 16 and the plug 22. (27), Fig. 5 (not shown), a seal 24 or 25 is also ruptured to permit forward movement of said plunger. The piston is then moved into a position intermediate the ends of each of said channels, Fig. 4 (not shown), marked by scribed lines 18, thus enabling the liquid component to flow via the channels into the compartment containing the drug component. These are then allowed to mix and the injection completed in the normal way. A sleeve 19 is provided as a seal around the barrel in the vicinity of the channels which in the particular extend completely through said wall.