WO2009030056A1

WO2009030056A1 - Protective cap for a needle

Info

Publication number: WO2009030056A1
Application number: PCT/CH2008/000362
Authority: WO
Inventors: Benedikt Scheller
Original assignee: Tecpharma Licensing Ag
Priority date: 2007-09-04
Filing date: 2008-09-02
Publication date: 2009-03-12

Abstract

The invention relates to a protective cap for an injection needle, comprising a reactive substance displaying a change in the chemical, physical or physico-chemical state thereof.

Description

Needle cap

The invention relates to a needle cap. In particular, the invention relates to a needle cap for an injection needle with a priming indicator disposed therein, wherein the priming indicator indicates a vented or a non-vented or an application ready or a non-ready operating state of an injection device. Furthermore, the invention relates to an injection device with such a needle cap.

The injection device may be a simple syringe having a reservoir containing a fluid product or a syringe having a carpule prefilled with a fluid product.

The injection device can be releasably connected to a needle carrier, which has a firmly welded or glued injection needle. Alternatively, the injection device can be firmly connected to a needle carrier, wherein the needle carrier has a firmly attached injection needle.

From EP 903157 A2 a packaged needle unit for an injection device is known, which consists of three separate elements, namely an outer Nadelverpackungshülse, a needle cap and a needle carrier with a fixedly disposed injection needle. In the initial state, these three elements are arranged one inside the other, so that the injection needle is enveloped by the needle cap and the needle cap is surrounded by the Nadelverpackungshülse. In use of the needle unit, the needle carrier is applied to an injection device and the needle packing sleeve and the needle protection cap can be removed.

WO 2005102419 A1 discloses an injection device for the administration of a fluid product from a prefilled carpule with priming function, preferably for medical, including veterinary, therapeutic, diagnostic, pharmaceutical and / or cosmetic applications. For these applications, it is important to administer a very specific fluid product dose. Since the cartridge of the injection device is not completely filled with the fluid product but contains air or other gas, without venting, the air or gas would be administered together with the fluid product. Consequently, none would correct product dose and health complications could occur. To ensure proper dosing, therefore, the air or gas that is in the carpule or accumulated during use must be removed.

Furthermore, the function of the injection device can also be impaired by the different filling level of the carpule. For this purpose, a carpule plug may be provided in the carpule, wherein the carpule plug is movable in the axial feed direction to an outlet of the carpule in order to displace the fluid product from the carpule. To move the carpule plug in the advancing direction, a flange fixedly connected to one end of a piston rod acts on the carpule plug. There may be some play between the carpule plug and the piston rod flange. Without ensuring that the carpule plug abuts the flange, product administration may reduce the administered product dose corresponding to this clearance. Consequently, no correct product dosage would be injected as well. To ensure correct dosing, a functional check must be performed prior to product administration to ensure that the carpule plug is adjacent to the flange of the piston rod.

In order to ensure a correct dosage, in particular for venting and to check the function of the injection device, the user is therefore prompted to perform so-called priming after each change of the cartridge and preferably also before each injection. For this purpose, a priming dose, which is preferably smaller than the active substance dose of the product to be injected, adjusted by means of a metering device and distributed by means of a dispensing device of the injection device.

To prime the injection device, the user needs some experience and practice. The user, at his discretion, pushes fluid product through the injection needle of the respective injection device until, by visual inspection, he detects the escape of the fluid product at the needle tip. Here it is possible that unnecessarily much fluid product is released for the purpose of priming, since in priming at its discretion more than necessary is often released from the fluid product. Moreover, visual inspection is often difficult for users with impaired vision and causes an increased risk that the priming process will not be performed correctly. The object of the invention is to provide a device which increases the safety due to the user friendliness, and that the priming process can be carried out properly before a targeted administration of the active substance.

This object is achieved by a needle cap as defined in the independent claim. Advantageous embodiments will be apparent from the dependent claims.

A needle cap, as the invention relates, may have a sleeve-shaped base body, which may have a closed end, hereinafter referred to as the distal end, and an open end, hereinafter referred to as the proximal end. The needle cap can be mounted on a needle carrier with a firmly connected injection needle so that the distal end of the needle cap surrounds the tip of the injection needle, the shell inner surface of the needle cap covers the shaft of the injection needle and the proximal end of the needle cap abuts the needle carrier. The needle carrier may be a fixed component of a disposable needle unit, a disposable syringe or a disposable injection device. In addition, an outer needle packing sleeve can be arranged around the needle protection cap and the needle carrier with the firmly attached injection needle. This needle wrapping sleeve may also comprise a sleeve-shaped base body which may have a closed end, hereinafter referred to as a distal end, and an open end, hereinafter referred to as a proximal end. The distal end of the needle wrapping sleeve may surround the distal end of the needle cap, the outer shell surface of the needle wrapping sleeve may encase the outer shell surface of the needle cap and the needle carrier with the fixed injection needle and optionally the syringe or injection device and the proximal end of the needle wrapping sleeve may be wrapped by a foil Closure or a cap-shaped lid be sealed sterile.

The needle protection cap according to the invention has on the inner surface, in particular on the inner surface of the distal end, on the shell inner surface of the sleeve-shaped base body and / or on the inner surface of the proximal end of the needle protection cap, a reactive substance, the change of a chemical, physical or physico-chemical State of the substance indicates, for example, by a visually recognizable aggregate change of the reactive substance, by a visually recognizable ion exchange reaction between the reactive substance and the fluid product or by a visually detectable catalytic reaction, wherein the reactive substance may be a catalyst. The reactive substance can be connected directly or indirectly, for example by an adhesive, to the needle protection cap. Alternatively, the reactive material may be an integral part of the needle guard. Advantageously, at least part of the interior of the needle protection cap contains the reactive substance.

In the priming state, the needle cap according to the invention can enter into a releasable frictional, positive or other connection with the needle carrier, which has a firmly connected injection needle. To perform the priming, a priming dose can be set by means of a metering device of an injection device and this priming dose can be released by means of a dispensing device of the injection device. Alternatively, the user, especially in the use of a syringe, may depress product by feel through the hypodermic needle of the device without adjustment of a metering device. The priming process is performed correctly if at least one drop of the fluid product is present at the hypodermic needle tip. This drop can wet the needle cap according to the invention. Due to the change in state of the reactive substance from one state to another state, for example from a dry to a wet state, the substance changes so that the user can visually recognize this change. Alternatively, the reactive species can visually represent an enthalpy or entropy change of the reactive species. Further, the reactive species can be altered by an ion exchange reaction between the fluid product and the reactive to visually detect this change, with the reactive material having different anions or cations before wetting with the fluid product than after wetting with the fluid product. In particular, the reactive substance may be an acid-base indicator. Preferably, a reactive substance is used for the needle cap, which discolors at the respective pH of the distributed product, for example, the pH indicator litmus at pH <4.5 turns red and at pH> 8.3 blue. The visual display can be used to verify that the priming process has been carried out correctly.

The needle protection cap can advantageously have a fluid-absorbing material, so that the drop that is released during the priming process is absorbed. Absorbing ensures that the consumer or the environment can not come into contact with the spilled fluid product, since the spilled droplets from the absorbing material is absorbed and can no longer flow out of the needle cap.

According to an exemplary embodiment of the present invention, the reactive substance may be arranged between the inner surface of the needle protection cap, in particular the inner surface of the distal end, the inner shell surface of the sleeve-shaped base body and / or the inner surface of the proximal end of the needle protection cap, and the liquid-absorbent material such that, for example, a threshold of spilled product must first be absorbed by the absorbent material before the reactive can react with the spilled product to release a noticeable sign. By this arrangement it can be ensured that the priming process is carried out with a minimum dose of fluid product.

According to a further embodiment of the present invention, the liquid-absorbing material may be a granulate or powder coated with the reactive substance, or the reactive substance may be formed from a liquid-absorbing material. The reactive material coated granules or powder or reactive material formed from a liquid absorbent material may be attached to the inner surface of the needle shield, in particular to the inner surface of the distal end, to the shell inner surface of the sleeve base body and / or to the inner surface be provided of the proximal end of the needle cap or be an integral part of the needle cap. Advantageously, at least part of the interior of the needle protection cap can be filled with the reactive substance-coated granules or powder or the reactive substance which is formed from a liquid-absorbing material. The reactive material coated granules or powder or reactive material formed from a liquid absorbent material may be directly or indirectly bonded to the needle shield, for example by an adhesive. It is advantageous that a chemical, physical or physico-chemical reaction of the reactive substance can take place with a smallest distributed product dose with delivery of a perceptible sign.

The liquid-absorbing material may be a natural or synthetic polymer, in particular cellulose or elastomer, for example polyurethane foam. This liquid-absorbing material may chemically combine or form a mixture with the reactive substance. Furthermore, between the reactive material or the liquid-absorbing material and the injection needle, a water-permeable material may be arranged so that no contamination of the injection needle with the reactive substance or the liquid-absorbing material takes place. The water-permeable material may be a nonwoven fabric made, for example, based on a polypropylene-polyethylene blend, or a perforated film, such as a perforated polypropylene, polyester or polyethylene film. The water-permeable material may also be made of cellulosic material.

A preferred embodiment of the invention will be explained below with reference to figures.

Show it:

Figure 1: A cross-sectional view of a needle unit with a needle cap and a packaging sleeve prior to priming.

Figure 2: A cross-sectional view of the needle unit with the needle cap after priming.

1 shows a cross-sectional view of a needle unit with a needle cap 2 and a Nadelverpackungshülse 1 before priming. The needle unit consists of a needle carrier 7, which carries a firmly welded or glued injection needle 6. The injection needle 6 is surrounded by the plugged onto the needle carrier 7 needle cap 2 and thus secured, so that the risk of accidental injury is reduced. The needle cap 2 can be pushed, snapped or screwed onto the needle carrier 7. The needle cap 2 is a detachable connection with the needle carrier 7 a. For this purpose, the needle carrier 7 has a circumferential on an outer circumferential surface of the needle carrier 7 ring 7a, which protrudes in the distal direction and is arranged approximately parallel to the transverse axis of the needle carrier 7. At the distal end of the ring 7a, a bead 7b is provided which projects radially inward and extends in the circumferential direction of the ring 7a. The bead 7b of the needle carrier 7 holds the needle cap 2 by the bead 7b of the needle carrier 7 is locked with a corresponding corresponding annular groove 2c of the needle cap 2. The annular groove 2c is located on the outer circumferential surface of the needle cap 2 and extends approximately parallel to the transverse axis of the needle cap 2. In a base body of Needle cap 2 is further provided at least one circular opening 2d, in this embodiment, two circular openings 2d are present. The needle packing sleeve 1 is plugged or screwed onto the needle protection cap 2 in order to pack the needle unit with the needle protection cap 2 in a sterile manner and to protect it from impacts or from external forces. The proximal end of the packaging sleeve 1 is closed with a film 8.

The needle protection cap according to the invention has an interior which is partly filled with cellulose granules 3. The filled with cellulose granules interior is limited by the distal end of the needle cap and at least through a part of the sleeve-shaped base body and by a part of a non-woven, in particular a polypropylene-polyethylene nonwoven. The cellulose granules are aggregated so that there is a gap 9 between the cellulose aggregate and the polypropylene polyethylene nonwoven. The polypropylene-polyethylene nonwoven fabric 5 is arranged to the transverse axis of the needle cap 2 and covers the tip of the injection needle 3 and at least part of the shaft of the injection needle 6. The polypropylene polyethylene non-woven 5 is shaped so that it is not in contact with the tip and the shaft of the injection needle 6 comes. For this purpose, the polypropylene-polyethylene nonwoven 5 is mixed with a fixing agent in order to increase the dimensional stability. Furthermore, the cellulose granules 3 are designed to absorb liquid. The cellulose granules 3 are coated with a pH-sensitive substance 4, in particular with a pH indicator such as litmus.

FIG. 2 shows a cross-sectional view of the needle unit with the needle protection cap 2 after priming. To prime the injection device prior to administration of a fluid product, such as insulin at pH 4, the foil 8 is withdrawn from the needle wrap sleeve 1 and the needle carrier 7, which has the firmly bonded injection needle 6, with the needle guard 2 and the needle wrap sleeve 1 mounted on the injection device, plugged, clamped, snapped or screwed. On the outer circumferential surface of the needle packing sleeve 1 are projections or grooves, which protrude radially outwardly, provided, which facilitate the attachment of the needle carrier 7 to the injection device. After attaching the needle carrier to the injection device, the needle wrapping sleeve 1 is pulled away from the needle unit. As described above, the priming is performed by setting a priming dose by means of a metering device of the injection device and distributed by means of a dispensing device of the injection device. The priming dose of insulin is thereby injected into the needle cap 2. The insulin permeates the polypropylene-polyethylene nonwoven 5 and is absorbed by the litmus cellulose aggregates contained in the needle cap 2, so that the insulin no longer flows out of the needle cap 2. The air or the gas, which is located in the interior of the needle cap 2, can escape through the openings 2 d of the base body of the needle cap 2 b. The acidic insulin enters into a protolysis equilibrium with the litmus cellulose granules. The initially colorless insulin takes on the color red of Lackmussäure. The red color indicates that the priming process was performed properly. Thereafter, the red colored needle cap 2 can be removed or removed from the needle carrier 7 and the product dose can be administered,

Reference numerals:

1 needle wrap sleeve

2 needle protection cap

2a distal end of the Nadeischutzkappe

2b Base body of the needle protection cap

2c groove

2d opening

3 cellulose granules

4 pH-sensitive substance

5 fleece

6 injection needle

7 needle carrier

7a ring

7b bead

8 needle wrap sleeve foil

9 gap

Claims

claims

Needle cap (2) for an injection needle (6), characterized in that the needle cap (2) comprises a reactive substance (4) indicating the change of a chemical, physical or physical-chemical state of the substance (4).

2. Needle protection cap according to claim 1, characterized in that the needle protection cap (2) has a liquid-absorbing material (3).

3. needle protection cap (2) according to claims 1 and 2, characterized in that the reactive substance (4) between the inner surface of the needle protection cap (2) and the liquid-absorbing material (3) is arranged.

4. Needle protection cap (2) according to claims 1 and 2, characterized in that the liquid-absorbing material (3) is a granulate or a powder and is coated with the reactive substance (4).

5. needle cap according to claims 1 and 2, characterized in that the reactive substance (4) is formed from a liquid-absorbing material (3).

6. needle cap (2) according to claim 1, characterized in that the reactive substance (4) indicates a dry-wet change visually.

7. Needle protection cap (2) according to claim 6, characterized in that the reactive substance (4) visually indicates a pH change.

8. Needle protection cap (2) according to claim 2, characterized in that the liquid-absorbing material (3) is a polymer.

9. needle cap (2) according to claim 8, characterized in that the liquid-absorbing material (3) is cellulose.

10. Injection device with a needle cap (2) according to any one of claims 1-9, characterized in that a first state is indicated, wherein in a carpule or an injection needle (6) of the injection device is air and a second state is displayed, wherein in the carpule or the injection needle (6) of the injection device, the air is removed.