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Title:
CONTAINER FILLED WITH A LOCAL ANAESTHETIC AND METHOD FOR PREPARING A MIXTURE OF A LOCAL ANAESTHETIC AND A SECOND LIQUID
Document Type and Number:
WIPO Patent Application WO/2013/188931
Kind Code:
A1
Abstract:
Container (1) that is intended to store a first liquid (13) and a second liquid (14) separately in separate chambers (4,5) and which is intended to let the liquids (13, 14) flow simultaneously out of the container (1), that is filled with a first liquid (13) and second liquid (14) in the separate chambers (4,5), characterised in that the first liquid (13) is a solution of a local anaesthetic and the second liquid (14) is an agent to adjust the pH of the first liquid (13).

Inventors:
VERMEYLEN JAN GUSTAAF M (BE)
Application Number:
PCT/BE2013/000028
Publication Date:
December 27, 2013
Filing Date:
June 07, 2013
Export Citation:
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Assignee:
VERMEYLEN JAN GUSTAAF M (BE)
International Classes:
A61M5/24; A61M5/32
Domestic Patent References:
WO2008051925A22008-05-02
WO2005016170A22005-02-24
WO2008001221A22008-01-03
Foreign References:
US20070225645A12007-09-27
US5137528A1992-08-11
AU2010101255A42010-12-23
Other References:
CLIFFORD R WHEELESS: "Local Anesthetic properties for Lidocaine", 16 December 2011 (2011-12-16), XP055051631, Retrieved from the Internet [retrieved on 20130129]
Attorney, Agent or Firm:
VAN VARENBERG, P. et al. (Arenbergstraat 13, Antwerpen, BE)
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Claims:
Claims .

1. - Container (1) that is intended to store a first liquid (13) and a second liquid (14) separately in separate chambers (4,5) and which is intended to let the liquids (13, 14) flow simultaneously out of the container (1), that is filled with a first liquid (13) and second liquid (14) in the separate chambers ( 4 , 5 ), characterised in that the first liquid (13) is a solution of a local anaesthetic and the second liquid (14) is an agent to adjust the pH of the first liquid (13).

2. - Container according to claim 1, characterised in that the second liquid (14) is a sodium bicarbonate solution in water .

3. - Container according to claim 1 or 2, characterised in that the local anaesthetic is lidocaine.

4. - Container according to any one of the previous claims, characterised in that the container (1) is arranged such that the first liquid (13) and the second liquid (14) can be mixed while they are in the container (1) .

5. - Container according to claim 4, characterised in that the container (1) is arranged such that the first liquid (13) and the second liquid (14), when they are mixed while in the container (1) , form a mixture with a pH between 7 and 7.5.

6. - Container according to any one of the previous claims, characterised in that the container (1) is arranged such that the first liquid (13) and the second liquid (14) can be mixed while they are in the container (1) because the container (1) is provided with a joint outlet channel (11) that connects to both chambers (4,5) and because the container (1) is designed to allow the first liquid (13) and the second liquid (14) to flow simultaneously from their chambers (4,5) to the joint outlet channel (11) and with a constant ratio of their outflow rates, whereby the mixing takes place in the joint outlet channel (15).

7. - Container according to claim 6, characterised in that there is a static mixer (12) in the joint outlet channel (11).

8. - Container according to any one of the previous claims, characterised in that the container (1) is a syringe (2) with two chambers (4,5), that comprises an injection needle (3), of which one chamber (4) is filled with the first liquid (13) and the other chamber (5) is filled with the second liquid (14), whereby each chamber (4,5) has a separate plunger (6,7), and the plungers (6,7) can be operated by a j oint . control (8).

9. - Container according to claim 8, characterised in that the plungers (6,7) can be moved by the joint control (8) over an equal linear distance, whereby the ratio between the areas of the cross-sections of the chambers (4,5) determines the ratio of the outflow rates from the chambers (4,5) while operating the joint control (8) .

10. - Container according to any one of the claims 1 to 5, characterised in that the container (1) is arranged such that the first liquid (13) and the second liquid (14) can be mixed while they are in the container (1) because the container (1) is provided with a partition between the chambers (4,5) that can be broken or removed.

11. - Use of a container (1) that is intended to store a first liquid (13) and a second liquid (14) separately in separate chambers (4,5) and is intended to let the liquids (13,14) flow out simultaneously, characterised in that the first liquid (13) is a solution of a local anaesthetic and the second liquid (14) is an agent to adjust the pH of the first liquid (13) .

12. - Method for making a mixture of a first liquid (13) and a second liquid (14), whereby the first liquid (13) is a soiution - o£ a- lccal - anaesthetic ana - whereby the "~ second liquid (14) is an agent to adjust the pH of the first liquid (13), characterised in that the first liquid (13) and the second liquid (14) are brought together from separate chambers (4,5) that form part of a joint container (1) for the liquids (13,14), and are forced -simultaneously out of the container (1) .

13. - Method according to claim 12, characterised in that the mixture is made such that it has a certain pH, and that the certain pH is between 7 and 7.5.

14. - Method according to claim 13, characterised in that the first liquid (13) and second liquid (14) are mixed in a joint outlet channel (11) that is provided in the container (1) and which connects to the separate chambers (4,5), whereby the first liquid (13) and second liquid (14) flow simultaneously to the joint outlet channel (11) with such a flow rate ratio that the certain pH is obtained.

15. - Method according to any one of the claims 12 to 14, characterised in that a container (1) according to any one of the claims 1 to 9 is used.

16. - Method according to claim 12 or 13, characterised in that a partition between the chambers (4,5) is removed or broken to enable mixing.

17. - Method according to any one of the claims 12 to 16, characterised in that the mixture is a mixture to be injected.

18. Method according to any one of the claims 12 to 17, characterised in that the method takes place before the mixture is injected. 19.- Method to administer a local anaesthetic to a patient, whereby a mixture of a first liquid (13, 14) and a second liquid is injected, whereby the first liquid (13) is a solution of a local anaesthetic and whereby the second liquid (14) is an agent to adjust the pH of the first liquid (13), characterised in that the mixture is made according to a method according to any one of the claims 12 to 18.

Description:
Container filled with a local anaesthetic and method for preparing a mixture of a local anaesthetic and a second liquid.

The present invention relates to a container filled with a local anaesthetic and a method for producing a mixture of a local anaesthetic and a second liquid. It is known that when administering a local anaesthetic, for example lidocaine, mixed with adrenalin or otherwise, pain can be experienced by the patient.

It is widely accepted that this is generally caused by the pH of the anaesthetic, which is 7 or less, and thus substantially lower than the physiological pH of approximately 7.3-7.4.

It is indeed possible to adjust the pH of the anaesthetic, but this can only be done relatively shortly before being administered because there are doubts about the stability, and thus the shelf life, of anaesthetics in such circumstances . This means that the doctor must perform various actions to reduce the pain felt by a patient, i.e.

- the affixing of a first extraction needle on a syringe;

- the taking of the desired quantity of anaesthetic out of a first container with the first extraction needle;

- the removal of the first extraction needle and the affixing of a second extraction needle on the syringe; - the taking of the desired quantity of agent to adjust the pH from a second container with the second extraction needle, and

- the affixing of an injection needle,

before the doctor can inject the desired mixture.

This has the disadvantages that many operations are needed that require time; that there is a risk of an incorrect ratio between the two products; that it is difficult to obtain an exact ratio, even when no mistakes are made, and that there is a risk of contamination of the one product by the other product .

Also the pierceable seal, for example a rubber stopper, of the containers is pierced a number of times because the containers contain a number of doses, which may give rise to sterility problems.

The purpose of the present invention is to provide a solution to at least one of the aforementioned and other disadvantages, by providing a container that is intended to store a first and a second liquid separately in separate chambers and is intended to let the liquids flow simultaneously out of the container, that is filled with a first and second liquid in the separate chambers, whereby the first liquid is a solution of a local anaesthetic and the second liquid is an agent to adjust the pH of the first liquid. By using such a container, and preferably connecting directly to an injection needle in which the outflowing liquids are forced and with which the mixture can be injected in the patient, mistakes are avoided, and a suitable mixture is ready much faster, more accurately with fewer operations, with a reduced risk of contamination.

In a preferred embodiment the second liquid is a sodium bicarbonate solution in water, which preferably has a concentration of 8.4%. In another preferred embodiment the local anaesthetic is lidocaine .

In another preferred embodiment the container is arranged such that the first liquid and the second liquid can be mixed while they are in the container.

This can be achieved by guiding the liquids to a mixing zone while flowing out, or by connecting the chambers relatively shortly before the outflow has to start so that the liquids can mix.

As a result a suitable solution can be prepared in the container, whereby mistakes and contamination are avoided. In a further preferred embodiment the container is arranged such that the first liquid and the second liquid, when they are mixed while in the container, form a mixture with a pH between 7 and 7.5. More preferably this pH is between 7.2 and 7.4. In this way the sensation of pain is reduced. The container can be arranged by designing the volumes of the chambers and/or the anticipated relative outflow rates, in combination with the nature and concentration of the liquids, such that that the desired pH is reached.

In a preferred embodiment the container is arranged such that the first liquid and the second liquid can be mixed while they are in the container, because the container is provided with a joint outlet channel that connects to both chambers and because the container is designed to allow the first and second liquid to flow simultaneously with a constant ratio of their outflow rates from their chambers to the joint outlet channel, whereby the mixing takes place in the joint outlet channel.

In this way the mixture is mixed immediately before the intended use while the liquids flow from the container, and only in the quantities needed to apply local anaesthetic, such that an unnecessarily large quantity of mixture is not produced .

In order to improve the mixing, a static mixer is preferably present in the joint outlet channel.

A practical embodiment of a container according to the invention is a syringe with two chambers, that can comprise an injection needle or otherwise, of which one chamber is filled with the first liquid and the other chamber is filled with the second liquid, whereby each chamber has a separate plunger, and the plungers of the chambers can be operated by a joint control.

Such syringes with two chambers, or two lumens, are known. Such a syringe can, even without an injection needle, be provided with a joint outlet channel, to which an injection needle that is fitted will connect.

Such a syringe can also be constructed such that an adapted needle is affixed over separate outlets of the chambers, whereby the cavity in the needle forms the joint outlet channel .

In another preferred embodiment the container is arranged such that the first liquid and the second liquid can be mixed while they are in the container, because the container is provided with a partition between the chambers that is breakable or removable.

As a result this container can be constructed as a syringe, or it can be a separate container, from which the mixture can be extracted after mixing by a conventional syringe with one chamber in order to then be injected.

The invention further concerns the use of a container that is intended to store a first and a second liquid separately in separate chambers and is intended to let the liquids flow out simultaneously, whereby the first liquid is a solution a local anaesthetic and the second liquid is an agent to adjust the pH of the first liquid. The invention also concerns a method for making a mixture of a first liquid and a second liquid to be injected, whereby the first liquid is a solution of a local anaesthetic and whereby the second liquid is an agent to adjust the pH of the first liquid, characterised in that the first liquid and the second liquid are brought together from separate chambers that form part of a joint container for the liquids, and are simultaneously forced out of the container .

The invention also concerns a method for administering a local anaesthetic to a patient, whereby a mixture of a first liquid and a second liquid is injected, whereby the first liquid is a solution of a local anaesthetic and whereby the second liquid is an agent to adjust the pH of the first liquid, characterised in that the mixture is made according to a method described above.

For the usage and the methods it is optional whether the mixture to be injected is injected from the container immediately after the mixing, or first a quantity of mixture is made that is then put in a conventional syringe and injected by means of that. Both with regard to the containers, the usage and the methods according to the invention, . the term ^agent' in the expression A agent to adjust the pH of the first liquid' means a chemical compound in pure form, dissolved form, or diluted form, or a mixture of such chemical compounds. With the intention of better showing the characteristics of the invention, a preferred embodiment of a container according to the invention is described hereinafter by way of an example, without any limiting nature, with reference to the accompanying drawings, wherein:

Figure 1 schematically shows a perspective view of a container according to the invention;

figure 2 shows a cross-section of the container of figure 1 according to line II-II;

figure 3 shows a cross-section of the container of figure 1 according to figure 2, in an earlier state of use . The container 1 shown in the drawings consists of a syringe 2 and an injection needle 3, that are connected together by means of a screw thread. The container 1 is shown in figures 1 and 2 in a situation that is ready to administer an injection.

The container 1 has a first chamber 4 for liquid and a second chamber 5 for liquid. The chambers 4 and 5 are, in this example but not necessarily, cylindrical and have a round cross-section.

The diameter Dl of the first chamber 4 in this example is 1.4 cm and the diameter D2 of the second chamber in this example is 0.5 cm. The areas of the cross-sections of the chambers 4 and 5 thus have a ratio of 8. The chambers 4 and 5 each have a plunger 6, 7 that can move in the channel concerned. The two plungers 6 and 7 are each connected to a joint control 8 in the form of a shaft with a pushbutton.

Chambers 4 and 5 each have an outlet channel 9 and 10. The outlet channels 9, 10 come together in a joint outlet channel 11 that has a part 11A located in the syringe 2 and a part 11B in the injection needle 3. h section 12 with a spiral form is affixed on the inside wall in the joint outlet channel 11.

The first chamber 4 is filled with a solution 13 of 1% lidocaine and 5 ppm adrenalin. The second chamber 5 is filled with a solution 14 of 8.4% sodium bicarbonate, NaHCC>3 . Both solutions 13 and 14 are liquids.

The use of the container 1 is as follows and is explained starting with figure 1.

Air bubbles are removed from the syringe 2 and injection needle 3 in the usual way. Then the injection needle is inserted into the body of the patient at the site where a local anaesthetic is needed.

By now pressing in the control 8 both plungers 6 and 7 move simultaneously in the chambers 4 and 5, and the solutions 13 and 14 in these chambers 4 and 5 are forced to their outlet channels 9 and 10, and from there further to the combined outlet channel 11, to finally outside the container 1 and into the body of the patient.

As a result eight times more lidocaine solution 13 than sodium bicarbonate solution 14 is injected, irrespective of the absolute speed of injection.

During their passage through the joint outlet channel the two solutions 13 and 14 are mixed into a mixture with a pH of approx 7.3, so that for most patients this mixture will not cause any sensation of pain, or only a weak one, during injection.

Because the plungers 6 and 7 are moved over the same distance, and the chambers 4 and 5 have a constant diameter Dl and D2, the ratio of the outflow rates from both chambers 4 and 5 is always the same and thus also the pH of the mixture. Due to the presence of section 12 with a spiral form, turbulence is brought about in the joint outlet channel 11, such that the mixing is improved. The section 12 thus acts as a static mixer. Figure 3 shows how the container 1 can be stored in two parts. The syringe 2 and the injection needle 3 are not yet connected together here.

The point where the outlet channels 9 and 10 come together, when the container is not yet ready for use, is blocked by a stopper 15. As a result the chambers 4,5 are completely separated from one another and no undesired premature mixing can occur.

When the container 1 has to be used, only the stopper 15 has to be removed and the injection needle 3 screwed onto the syringe 2.

The section 12 with spiral form can also be affixed in the syringe 2 instead of the injection needle 3. Here a means other than a stopper 15 for closing the chambers 4,5, would have to be provided in the period that the solutions 13, 14 are not yet used.

The containers 1 according to the invention are intended for single use.

The areas of the cross-sections of the chambers 4 and 5 in this specific example have a ratio of 8. However this ratio can be different in different cases, and is related to the nature and concentration of the liquids to be used.

For example it may be practical to use a syringe with two identical chambers, so that equal volumes of the solutions are injected, whereby the concentrations of the solutions are adjusted to the syringe that is available, in order to obtain the desired pH of the mixture.

The present invention is by no means limited to the embodiments described as an example and shown in the drawings, but a container according to the invention can be realised in all kinds of variants, without departing from the scope of the invention.