The present invention is directed to a storing and dispensing system for substances, preferably flowable substances, and a method which enables air free filling and storing a precise predetermined amount of substance. The storing and dispensing system of the present invention further provides a self-opening feature providing extended convenience in handling of the dispensing system.
Standard syringe configurations are generally used as dose dispensing or delivering systems. The standard syringe configurations are either filled by a user or pre-filled with the desired substance. The manual filling of a standard syringe has the drawback that a precise filling volume depends on the user's handling skills, which due to the variability in skills leads to variability of volume. When the syringe is pre-filled, the filling tolerance is typically dependent on the filling device, wherein devices with a more precise filling are more expensive. For small containers of a rather low filling volume, as are used in the dental field, a precise filling of the required volume is essential especially for two- or multi-component compositions wherein a precise mixing ratio of the components is essential for the quality of the mixture.
A further drawback of standard pre-filled syringe configurations is the difficulty to provide encapsulation of the substance without voids or air bubbles. A precise filled volume of a substance with a reduced amount of voids or bubbles would for instance inject less air into the patient's blood stream, in case the syringe is used for pharmaceutical substances. Furthermore, precise filled volumes for two- or multi-component compositions with a reduced amount of voids or bubbles in the mixture would enhance the strength and durability of the mixed composition.
U.S. Pat. No. 6,261,094 is directed to a capsule construction for dispensing an ultra dense composite dental restorative material by a syringe wherein the capsules include a body portion defining a reservoir and a connected nozzle angularly disposed relative to the axis of the body portion. The body portion defining a reservoir has an internal diameter which is equal to or only slightly larger than the internal diameter of the nozzle and the discharge orifice. A sealing cap is provided at one end of the capsule and a bi-directional piston is provided at the other end for extruding the ultra dense material from the capsule. The internal surfaces of the capsules may be coated with lubricating liquid compatible with the ultra dense composite material to be dispensed thereby.
U.S. Pat. No. 3,603,310 relates to disposable dispensing syringes having a liquid-filled compartment which is separate from contact with a syringe cannula. The liquid-filled compartment is provided between a piercable inner piston and an outer piston. In storage the inner piston is partly pierced by the inner end of a two-way syringe cannula. The inner piston is axially movable from the sealing position to a dispensing position in which the inner end of the cannula pierces the inner piston and permits the liquid to be dispensed from the compartment.
Typical dispensing systems do not have a system for storing and later mixing material components and, therefore, may be inconvenient when dispensing substances which are made of material components that have to be mixed just before use. In this case, the material components first have to be mixed and then filled into the dispenser system, which can lead to the presence of undesirable voids and bubbles.
Therefore, there is a need for an improved storing and dispensing system and method offering improved bubble-free filling and storage of an exact amount of substance with minimal effort.
According to a first aspect, the present invention provides a system for storing and dispensing a substance, comprising at least one compartment for storing a substance, wherein the compartment has a back end and a front end for filling and dispensing the substance, respectively. The compartment further comprises a vent, preferably in the vicinity of the back end, and a movable front plug within the compartment downstream of the vent. The compartment is closeable with a displaceable rear plug or piston at the back end, wherein the compartment defines a predetermined volume between the vent and the movable front plug.
According to a second aspect, the present invention provides a system for storing and dispensing a substance comprising at least one compartment with a front end and a back end, a front plug and a displaceable rear piston. The front plug and the back piston are adapted to be spaced apart in the compartment to define a volume within the compartment, and are further adapted to be axially or longitudinally movable within the compartment. The compartment further comprises a vent preferably in the vicinity of the back end, wherein the volume of the chamber between the vent and the front plug in its initial position define a predetermined volume.
According to a third aspect, the present invention provides a system for storing and dispensing a substance comprising at least one compartment with a front end and a back end, a front plug and a displaceable rear piston. The front plug and the piston are adapted to be spaced apart in the compartment to define a volume within the compartment, and are further adapted to be axially movable within the compartment. The compartment further comprises an annular vent groove in the vicinity of the back end, wherein the volume in the chamber between the vent groove and the front plug placed in an initial position between the vent groove and the front end define a predetermined volume.
The vent of the present invention is preferably formed as an annular groove near the back end of the compartment. The vent may also be formed as a longitudinal groove, i.e., substantially parallel to the longitudinal axis of the compartment. Alternatively, the vent may be formed as a tapered portion at the back end of the compartment. The vent may also be formed as a widened portion and/or stepped configuration at the back end with at least one step.
The fill volume of the chamber may be filled with any material, e.g. with liquid, viscous or highly viscous substances, with pharmaceutical substances, dental fluid pharmaceuticals (such as enzymatic caries removal solutions), pastes, or any other substance(s) which is or are preferably stored and dispensed without interfering gas bubbles.
The front plug is preferably cylindrical having a circular cross-section. However, other cross-sectional shapes of the plug (e.g., square, polygonal, etc.) that match the shape of the compartment are also encompassed by the present invention. Preferably, the front plug comprises at least one sealing bulge. Even more preferred, the plug comprises at least first and second sealing bulges next to a front end and a back end of the plug, respectively, such as the plug shown in
Preferably, the front plug is slightly harder to move than the rear piston so that if the rear piston is pushed to remove air and excess material the front plug does not move until the air and excess material is escaped. For example, the compartment is slightly tapered towards the front end so that a slightly higher friction is provided at the front end. In this case, the front plug and the rear piston can have the same diameter. Alternatively, the diameter of the front plug is slightly larger than the diameter of the rear piston. As a further alternative, the front plug and the rear piston are made from different materials (e.g. materials having different Shore Hardnesses).
The system of the present invention may be provided with a self-opening feature, such that for instance a fluid communication pathway between a compartment and an orifice is provided when the movable front plug is moved from its initial position towards the front end of the compartment.
According to another aspect, the present invention provides a system for storing and dispensing at least two substances. Additionally, the system may also assist the mixing of at least two substances. According to this aspect, the system comprises at least two separate compartments, wherein each compartment comprises a plug and a piston as explained above. The system further comprises an outlet for mixing and dispensing the substances, wherein each compartment comprises an orifice providing a fluid communication pathway between the respective compartments and the outlet. When the plugs are moved from their initial position towards the front end of the compartments and the plugs have passed the orifices, a fluid communication pathway between each compartment and the outlet is created enabling the substances of both compartments to flow towards the outlet. Preferably the compartments and the outlet are integrally formed as one piece. The system may further comprise a mixer such a static mixer in the outlet. Alternatively, the two compartments can comprise individual outlets in case an immediate mixing of the substances is not desired.
The system of the present invention preferably comprises a plunger for each compartment for applying pressure to the piston. Preferably but not necessarily, the plunger and the pistons are integrally formed as one piece.
Moreover, the invention is directed to a method of gas- or air-free filling and sealing a system for storing an exact amount of substances in a predetermined fill volume. The method comprises the steps of i) providing a compartment with a plug in an initial position inside the compartment; ii) filling the compartment from the back end with a substance at least up to a vent; wherein the initial position of the plug and the vent defines a predetermined volume; iii) placing a piston into the back end of the compartment; iv) further advancing the piston until the predetermined volume is air-free sealed between the piston and the plug. Preferably, between step iii) and step iv) the remaining air between the piston and the fill level of the substance is compressed.
The excess of substance filled above the vent is able to escape into or through the vent such that between the piston and the plug the predetermined volume of substance is enclosed. Depending on the design of the vent, the excess of substance is either removable from the system or maintained in the system. Preferably the excess of substance is sealed between the first and second sealing bulges of the piston as described above.
Further, the invention is directed to a method of mixing at least two substances with a storing and dispensing system according to the present invention with the steps of: (a) displacing the piston(s) towards the front end of the compartments and simultaneously displacing the plugs by hydraulic transmission of force via the substance stored in the compartment; (b) opening orifice when the plugs approach the front end of their respective compartments thus providing fluid communication between the compartments and the outlet; further advancing the pistons thus extruding the substances from the compartments into the outlet.
The present invention is advantageous in that the system enables air-or gas-free filling of a storing and dispensing system for substances without the need of complicated or expensive machinery or processes. The present invention is furthermore advantageous in that it provides a precise predetermined volume in the compartment even when used with filling devices with relatively large filling tolerances. Thus, the present invention is also advantageous in providing a precise volume of substances for small containers of a rather low filling volume as are used in the dental field. The present invention is also advantageous in that it provides a precise volume of substances without the high costs associated with precise filling machinery.
The present invention is further advantageous in that it provides a self-opening feature which means that no separate operation or step is necessary to open the syringe (e. g. remove cap, assemble tip etc.) before use. The syringe will automatically open when the plunger is advanced to a predetermined point, and provides precisely-controllable dispensing of a substance.
The present invention is further advantageous in that it provides a precise mixing ratio of the components especially for two- or multi-component compositions. The present invention is advantageous in that material components for substances can be pre-filled substantially without voids or air bubbles and stored in the dispensing system and then mixed automatically within the system prior to or during use. Also, since the delivery system of the present invention is disposable, there is no effort needed to clean the system after use.
Further advantages will be apparent from the following description and drawings of the preferred embodiments of the present invention:
a is a cross-sectional view of a cartridge with a vent according to a first embodiment of the present invention;
b is a cross-sectional view of a cartridge with a vent according to a second embodiment of the present invention;
c is a cross-sectional view of a cartridge with a vent according to a third embodiment of the present invention;
a to 2e are cross-sectional views of a cartridge at different filling stages illustrating an air free filling of the cartridge with a vent according to a first embodiment of the present invention;
a and 3b are partly enlarged cross-sectional views according to
a and 4b are cross-sectional views of a cartridge with a vent according to the first embodiment of the present invention showing different plug positions during storage of the substance;
c is a cross-sectional view of a cartridge with a vent according to a fourth embodiment of the present invention;
a to 5d are cross-sectional views of a dispensing system with two compartments at different filling stages illustrating an air free filling of the cartridge with vents according an embodiment of the present invention;
a and 7b are cross-sectional views of a dispensing system with two compartments at advancing stages of the plungers with a vent according an embodiment of the present invention;
a to 9c are cross-sectional views of a dispensing system with one compartment at different dispensing stages with a vent according an embodiment of the present invention.
In one preferred embodiment of the present invention as shown in
The cartridge 10 according to the first embodiment of the invention furthermore comprises an annular vent groove 50 in the vicinity of the back end 22, which enables substantially air-free filling of the system. The vent groove eliminates or at least reduces that air is captured in the compartment. The cartridge is sealed at the back end 22 with a piston 32 (see
The cartridge 10 of the dispensing system 42 has a body which is preferably made of relatively stiff material, for example polypropylene, polycarbonate, or polyoxymethylene. The body may be injection-molded.
b shows a second embodiment of a vent, wherein the vent is designed as a tapered portion 51 at the back end of the compartment 20.
Turning now to
In the next step, as shown in
Depending on the requirements of the compartment there are options for the “storage position” of the piston shown in
As an option instead of an annular groove, a longitudinal groove 53 can be used as shown in
Turning now to
In another preferred embodiment of the present invention, as shown in
The filling process for this embodiment is similar to the process as described above with respect to
Preferably, the outlet 61 is designed as one channel being in fluid communication with both compartments 20a and 20b via the orifices 60a and 60b, thus allowing the substance components to flow together when they are extruded from the compartments simultaneously. However, alternatively, the cartridge comprises an outlet with two separate channels to keep the materials separate in a downstream step or to be used as single components.
Preferably the cartridge 10 with the two compartments 20a and 20b is integrally formed in a single piece. An optional separation wall 11 separates the two compartments 20a and 20b. The separation wall 11 has an aperture close to the front end of the cartridge 10, thus forming the orifices 60a and 60b and providing fluid communication between the two compartments 20a and 20b as well as with the outlet (see, e.g.,
As described above, the substances 25a, 25b are encapsulated between pistons 32a, 32b and the plugs 31a, 31b within the compartments 20a and 20b. To extrude the material from the cartridge, the pistons 32a, 32b are pushed forward. Since the material is preferably relatively incompressible this forces the front plugs 31a, 31b to be moved forward as well. As soon as the plugs 31a, 31b have passed the aperture or the orifices 60a and 60b, fluid communication between both compartments 20a and 20b and the outlet 61 is created. This enables the substances of both compartments to flow into the outlet 61. The outlet may contain a static mixer (not shown).
It has been observed that moving two pistons and two plugs at a time may require a rather high initial force, because the static forces necessary to begin moving each piston and plug from a resting position would all be applied at the same time. Depending on the material of the pistons and plugs and the cartridge as well as depending on the time the parts have been stored in assembled condition, this initiation force usually is considerably higher than the dynamic (sliding) friction of the plugs and pistons once they are in motion. This means that a solution is preferred that would enable easier initial movement of the pistons and plugs.
According to one embodiment, annular recesses 521 are integrated in the back end of the compartments, as shown in
According to another embodiment, shown in
The present invention is not limited to the specific illustrated embodiments. Moreover, the present invention is realized by the features of the claims and any obvious modifications thereof.
Number | Date | Country | Kind |
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05012016.1 | Jun 2005 | EP | regional |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US2006/021325 | 6/1/2006 | WO | 00 | 12/3/2007 |