Lubrication of an injection needle

Abstract

A method for lubricating an injection needle when used multiple times at a single occasion to penetrate a support, the method including the steps of: a) depositing a layer of a lubricating composition on the support; b) penetrating multiple times the layer of the lubricating composition deposited in step a) with the injection needle, thereby providing a lubricated injection needle having a deposited layer of the lubricating composition thereon.

Claims

1. A method for lubricating an injection needle when used multiple times at a single occasion to penetrate a human skin support, the method comprising: a) depositing a layer of a lubricating composition on the human skin support; and b) penetrating multiple times in a single occasion the layer of the lubricating composition deposited in step a) with an injection needle, thereby providing a lubricated injection needle having a deposited layer of the lubricating composition thereon, the number of times being more than 30, but less than or equal to 50, wherein the injection needle is lubricated after each of the multiple times in the single occasion so as to maintain lubrication of the injection needle during the single occasion, wherein the lubricating composition comprises silicone, and wherein the lubricating composition comprises silicone in an amount within the range of from 25% to 30% by weight of the total composition.

2. The method according to claim 1, wherein step a) is performed once.

3. The method according to claim 1, wherein step b) is performed at least 10 times.

4. The method according to claim 1, wherein the lubricating composition is sterile.

5. The method of claim 1, wherein an amount of lubricating composition deposited on the human skin support is within the range of 0.01 g/cm.sup.2 to 0.1 g/cm.sup.2.

6. The method of claim 1, wherein the injection needle is lubricated after each of the multiple times in the single occasion so as to re-lubricate the needle multiple times.

7. The method of claim 1, wherein: the lubricating composition is penetrated prior to penetration of the human skin support, such that the lubricating composition is a first layer penetrated by the injection needle and the human skin support is a second layer penetrated by the injection needle.

8. The method of claim 7, wherein a penetration angle between the injection needle and the lubricating composition is smaller than 90°.

9. The method of claim 1, wherein the injection needle comprises a cutting edge and a hollow shaft.

10. The method of claim 9, wherein: when the injection needle is penetrating into the human skin support, a first penetration force acts in a first direction toward the cutting edge when the human skin support is penetrated by the cutting edge, and a second penetration force acts in a second direction along the hollow shaft and opposite to the first direction.

11. The method of claim 1, wherein the injection needle comprises two grinding surfaces.

12. The method of claim 1, wherein the lubricating composition comprises silicone in an amount of 25% by weight of the total composition.

13. A method for injecting multiple doses of an injectable composition into human skin at a single occasion, the method comprising: a) depositing a layer of a lubricating composition on the skin; b) penetrating multiple times in a single occasion the layer of the lubricating composition deposited in step a) with an injection needle, thereby providing a lubricated injection needle having a deposited layer of the lubricating composition thereon, the number of times being more than 30, but less than or equal to 50; and c) injecting a dose of the injectable composition each time the injection needle penetrates the skin, wherein the injection needle is lubricated after each of the multiple times in the single occasion so as to maintain lubrication of the injection needle during the single occasion, wherein the lubricating composition comprises silicone, and wherein the lubricating composition comprises silicone in an amount within the range of from 25% to 30% by weight of the total composition.

14. The method according to claim 13, wherein the injectable composition is selected from a filler and a toxin composition.

15. The method according to claim 14, wherein the injectable composition is a filler composition containing a filler selected from hyaluronic acid and derivatives thereof, in linear or cross-linked form, collagen, poly acrylamide, calcium hydroxyl apatite, poly lactide acid, and poly (methyl metacrylate).

16. The method according to claim 15, wherein the filler is cross-linked hyaluronic acid.

17. The method according to claim 14, wherein the injectable composition is a toxin composition containing botulinum toxin.

18. The method according to claim 13, wherein the method is a cosmetic treatment method.

19. The method of claim 13, wherein the lubricating composition comprises silicone in an amount of 25% by weight of the total composition.

Description

(1) Referring now to the Figures, which are exemplary embodiments, wherein:

(2) FIG. 1 is a flow chart depicting one example of a method for lubricating an injection needle when used multiple times.

(3) FIG. 2 is a schematic view of a syringe having an injection needle.

(4) FIG. 3 is a schematic view of an injection needle.

(5) FIG. 4 is a cross-sectional view of a syringe directed towards a deposited layer of a lubricating composition on a support.

(6) FIG. 5 is a flow chart depicting one example of a method for injecting multiple doses of an injectable composition into human skin at a single occasion.

(7) FIG. 6 is a table describing a standard test of an injection needle penetrating a support (http://www.iso.org/iso/catalogue_detail.htm?csnumber=58079).

(8) FIG. 7 is a graph illustrating the penetration force F.sub.2 of the injection needle after it had been used multiple times.

(9) FIG. 8 is a graph illustrating the penetration force F.sub.R of the injection needle after it had been used multiple times.

(10) In order to provide improved and simplified solutions for the use of an injection needle multiple times at a single occasion, it has been found important to efficiently maintain the injection needle lubricated.

(11) FIG. 1 is a flow chart of a method 100 for lubricating an injection needle when used multiple times at a single occasion to penetrate a support according to one embodiment of the present invention. In a first step 101, a layer of a lubricating composition is deposited on the support. Thereafter, the layer of the lubricating composition deposited in step 101 is penetrated multiple times with the injection needle, thereby providing a lubricated injection needle having a deposited layer of the lubricating composition thereon.

(12) The term “injection needle”, should herein be understood as a hollow needle or a solid needle intended to be used with a syringe to penetrate a lubricating composition, such as in the direction of the support. The injection needle is usually made of stainless steel.

(13) The term “lubricating composition”, should herein be understood as any composition which is lubricating. The lubricating composition may reduce friction between two, in relation to each other, moving surfaces. The lubricating composition may be sterilisable. A preferred lubricating composition is a skin lotion, cream or gel, optionally containing silicone.

(14) The term “single occasion”, should herein be understood as an occasion, limited in time, which occurs once, wherein the injection needle may be used for penetration multiple times. A typical treatment occasion will last for 1 to 60 min, such as 1 to 15 min.

(15) An injection needle, which is intended to be used once, may according to the invention be used for penetration multiple times. The injection needle may further in the inventive method be efficiently re-lubricated each of the multiple times the injection needle is used for penetration. In the inventive method, a conventional injection needle, such as the injection needle intended to be used once, may be used multiple times. Hence, the inventive method enables reuse of the injection needle.

(16) In the prior art method presented in the background of the invention, a specific apparatus has been suggested for e.g. lubricating the injection needle. In the inventive method, there is no need for such a special apparatus for lubricating the injection needle since the present invention inventively involves a simplified way of lubricating the injection needle. There is further in the present invention no need for any temporary storage of the injection needle in-between each of its multiple uses, at a single occasion, for lubricating the injection needle.

(17) The layer of the lubricating composition may, in step 101, be topically deposited on the support.

(18) The injection needle may be a hypodermic needle. The injection needle may also be a solid needle.

(19) Another exemplary embodiment will now be described with reference to FIG. 2. FIG. 2 shows an injection device 200 comprising an injection needle 20, which may be reversibly interconnected by a Luer taper connection 21 to a syringe 22. An enlargement of the injection needle is seen in FIG. 3. The injection needle 30 comprises a cutting edge 33 and a hollow shaft 34. A preferred needle has two grinding angles (so-called facette grinding), i.e. four surfaces.

(20) Another exemplary embodiment will now be described with reference to FIG. 4. FIG. 4 shows an arrangement 400 of the method for lubricating the injection needle when used multiple times at a single occasion. FIG. 4 is a cross-sectional side view of a syringe directed towards a deposited layer of a lubricating composition 46 on a support 47. The layer is deposited on the support with an amount of the lubricating composition within the range of from 0.001 to 1 g/cm.sup.2, such as within the range of 0.01 to 0.1 g/cm.sup.2, or such within the range of from 0.01 to 0.05 g/cm.sup.2. The injection device 200 having an injection needle 40, reversibly interconnected by the Luer taper connection 41 to the syringe 42 is illustrated in the direction towards the support. By moving the injection device 200 in the direction towards the support, the injection needle may penetrate the layer of the lubricating composition 46, thereby providing a lubricated injection needle having a deposited layer of the lubricating composition 46 thereon, such as each of the multiple times the injection needle 40 is used. Although, the injection device 200 is illustrated substantially perpendicular to the layer of the lubricating composition 46, the injection device 200 may penetrate the layer of the lubricating composition with an angle α smaller than 90°, the angle being defined between the injection device 200 and the lubricating composition 46 as long as the first layer to be penetrated by the injection needle 40 is the layer of lubricating composition 46.

(21) Another exemplary embodiment will now be described with reference to FIG. 5. FIG. 5 is a flow chart of a method 500 for injecting multiple doses of an injectable composition into human skin at a single occasion according to an embodiment of the present invention. In a first step 501, a layer of a lubricating composition is deposited on the skin. Thereafter, the layer of the lubricating composition deposited in step 501 and the skin is, in a further step 502, penetrated multiple times with the injection needle, thereby providing a lubricated injection needle having a deposited layer of the lubricating composition thereon, such as each of the multiple times the injection needle is used. Step 502 is followed by step 503 of injecting a dose of the injectable composition each time the injection needle penetrates the skin.

(22) The term “injectable composition”, should herein be understood as any composition which may be injectable through or via the injection needle into a support. The injectable composition may be a filler and/or a toxin composition.

(23) The filler may for example be hyaluronic acid. Hyaluronic acid refers to a compound constituted of series of glucuronic acid and of N-acetylglucosamine. Hyaluronic acid can be in the form of a pharmaceutically acceptable salt or derivatives thereof, particularly a sodium or potassium salt. Hyaluronic acid may be used in various forms: a salt, a derivative such as an ester or an amide. Hyaluronic acid may be in a linear or in a cross-linked form. When the hyaluronic acid is in its cross-linked form, the hyaluronic acid's individual chains are chemically bound (or cross-linked) together into a soft solid, or gel. The strength or firmness of the gel depends on the degree of cross-linking of the individual acid chains.

(24) Another filler may for example be collagen. Further examples of the filler may be poly acrylamide, calcium hydroxyl apatite, poly lactide acid, poly (methyl metacrylate).

(25) An example of the toxin is botulinum toxin, which herein refers to a botulinum neurotoxin produced by Clostridium botulinum or Clostridium baratii, as well as a botulinum toxin, or the light chain or the heavy chain thereof which are subsequently combined together, made by genetic recombinant techniques using a non-Clostridial species. Botulinum toxin herein encompasses the botulinum toxin serotypes A, B, C, D, E, F and G and their subtypes. Botulinum toxin also encompasses both a botulinum toxin complex, i.e. the complexes of approximate molecular weight 300, 600 and 900 kDa or other complexes as produced naturally by the bacteria, as well as purified botulinum toxin, having approximately 150 kDa in molecular weight. The purified botulinum toxin is a botulinum neurotoxin that is isolated, separated or substantially isolated or separated, from other proteins. The botulinum toxin further encompasses modified botulinum toxin, which is a botulinum toxin that has at least one of its amino acids deleted, modified, or replaced, as compared to native botulinum toxin.

(26) The skin comprises three layers, which knowingly to the person skilled in the art are; epidermis, the outermost layer of the skin, dermis, the layer beneath epidermis, and the deeper subcutaneous tissue or hypodermis, the layer beneath both epidermis and dermis. The penetration of the skin in step 503, in order to inject a dose of the injectable composition, may be minimal invasive, such as the injection needle may penetrate the epidermis and may further penetrate into the layer of dermis. The deeper subcutaneous tissue or hypodermis may not be reached by the injection needle nor penetrated by the injection needle according to the present invention.

(27) The thickness of the epidermis and dermis of the skin may vary in different parts of the skin of the human body. The epidermis may for example have a thickness of 0.05 mm in the eyelids and a thickness of 1.5 mm in the palms and soles. The thickness of the dermis may also vary in different parts of the human body. The dermis may for example have a thickness of 0.3 mm in the eyelids and a thickness of 1.5 mm in the palms and soles. Hence, the penetration depth of the injection needle is shallow. Due to the different thicknesses of the epidermis and dermis of the skin, the injection needle may penetrate to a penetration depth, which varies depending on where on the human body the injectable composition is injected. The penetration depth further varies depending on the angle α with which the injection device 200 is penetrating the skin.

(28) “Penetration depth” is herein referred to as a measure of how deep the injection needle may penetrate through the lubricating composition and into the support, in order to reach dermis of the skin. The penetration depth of the injection needle may vary depending on the length of the injection needle and depending on the inclination, i.e. the angle α, of which the injection needle penetrates into the skin. If the injection needle penetrates the skin almost horizontally, the penetration depth may be within the range of from 1 to 50 mm and if the injection needle penetrates the skin almost vertically, the penetration depth may be within the range of from 1 to 10 mm.

(29) The dose of the injectable composition may be injected into epidermis or dermis of the skin. The dose of the injectable composition may preferably be injected into dermis of the skin. The dose of the injectable composition may be injected into dermis of for example the eyelid, lip, fore head, palm, backhand, sole of feet and/or armpit.

(30) The method according to the invention is particularly useful in cosmetic treatment, e.g. for multiple administrations of the injectable composition into the skin without any medical risk for the treated subject.

(31) The method according to the invention may also be useful in medical treatments, in particular involving botulinum toxin.

EXAMPLES

(32) Aim of Test

(33) The inventors investigated how the lubricating composition affected the penetration force acting on the injection needle when used multiple times at a single occasion. The penetration forces measured were the penetration force F.sub.2 and the penetration force F.sub.R.

(34) Principle of an Injection Needle Penetration Measurement

(35) FIG. 6 is a table describing a standard test (ISO/DIS 11040-4) of an injection needle penetrating a support. The penetration force F.sub.0 represents when a needle tip of the injection needle penetrates a test foil. The penetration force F.sub.1 represents when the cutting edge of the injection needle passes through the test foil. The penetration force F.sub.2 represents when the test foil is dilated, i.e. when the heel passes the foil. The penetration force F.sub.3, i.e. F.sub.R, represents when the shaft of the injection needle penetrates the test foil.

(36) Materials

(37) The following chemicals as well as materials and equipment were used in the tests.

(38) Chemicals

(39) Skin cream base: ACO Body skinlotion, unscented, art no 100561 from ACO HUD NORDIC AB (SE-Upplands Va{umlaut over (s)}by). The skin cream base comprises aqua, paraffin liquid, glycerine, isopropyl myristine, parraffin, glyceryl stearate citrate, glyceryl stearate, cetearyl alcohol, acrylates/C10-30 alkyl acrylate, crosspolymer, xantham gum, sodium hydroxide phenoxyethanol, potassium sorbate and sodium benzoate. Silicone, DC 360, 1000 CST.
Materials and Equipment Test foil: DEKATEST PU 0.08 mm/width 80 mm/length 1.000 mm from Melab, lot 271009. Injection needle with facette grinding: Terumo Europe N.V., 29G×½″ TW (0.33×12 mm), Belgium, lot 1202010. Skin Pad: Q-Med training skin pad 15-77375. Test equipment: Custom made equipment based on the syringe pump ProSense B.V. Model number NE-1000 and serial number 245238/17668+load cell. Speed: 352.5 μm/s. Mixing equipment for mixing skin cream base with silicone: Polytron 10-35 GT, homogenizer.
Test Method
1. Preparation of a Lubricating Composition

(40) Firstly, five different lubricating compositions were prepared. Three of the lubricating compositions were prepared by mixing the skin cream base with silicone to a ratio of skin cream base vs. silicone, having 95/5, 75/25, and 50/50, respectively. The remaining two lubricating compositions were left unmixed, 100/0, i.e. 100% skin cream base and 0/100, i.e. 100% silicone, respectively.

(41) 2. Depositing the Lubricating Composition on a Support

(42) Thereafter the five different lubricating compositions were deposited, as a layer of the lubricating composition, on different supports, i.e. skin pads, thereby achieving five prepared skin pads, each of them having a different prepared lubricating composition thereon. The lubricating composition was deposited on each of the skin pads to a layer thickness of the lubricating composition of 0.03 g/cm.sup.2. One skin pad was left without any lubricating compositions and used as a reference in the test.

(43) 3. Penetrating a Prepared Skin Pad with an Injection Needle

(44) Referring now to the skin pad having a deposited layer of 100% skin cream base (100/0), an injection needle, according to the above referenced model, penetrated once, in the direction of the skin pad, firstly the deposited lubricating composition, thereby providing a lubricated injection needle having a deposited layer of the lubricating composition thereon, and secondly the skin pad. A penetration is herein referred to as penetrating in two directions, firstly into the skin pad and secondly out of the skin pad, passing the lubricating composition twice.

(45) 4. Measuring a Penetration Force Acting on the Injection Needle

(46) Subsequent to the first penetration of the injection needle through the lubricating composition of 100% skin cream base (100/0) and into the skin pad, the injection needle was mounted on the test equipment, presented above, to measure its penetration force. While recording the penetration force, the injection needle was let to penetrate a test foil, according to the above referenced test foil, made of an elastic plastic film of polyurethane film having a thickness of 0.08 mm.

(47) 5. Repeating the Penetration and Measuring Step of a First Test Series

(48) After the measure of the penetration force acting on the injection needle, which had penetrated the skin pad having 100% skin cream base thereon, the injection needle was once again let to penetrate the skin pad having the deposited layer of 100% skin cream base. Thereafter the penetration force of the injection needle was once again measured according to step 4.

(49) The step 3 and 4 were repeated and the penetration force was measured after the 3.sup.th, 4.sup.th, 5.sup.th, 10.sup.th, 25.sup.th and 50.sup.th penetration in the skin pad, respectively, thereby achieving a test result from a first test series.

(50) The repeatability of the test method was tested by testing a skin pad having the same layer of lubricating composition deposited thereon for another two test series á 50 penetrations according to step 3 to 5. In the beginning of each test series, a new injection needle was used.

(51) 6. Testing the Remaining Skin Pads, Prepared in Step 1 and 2

(52) The same test procedure and penetration force measurement, as in step 3 to 5, were performed with the skin pads each having lubricating composition ratios of skin cream base vs. silicone of 95/5, 75/25, and 50/50, as well as 100% silicone and to the skin pad without having any lubricating composition, i.e. the reference skin pad.

(53) Results

(54) The penetration force measured in the tests was the penetration force F.sub.2 and the penetration force F.sub.R (F.sub.3) as depicted in FIG. 6. The penetration force F.sub.2 acts, in the direction towards the cutting edge of the injection needle when the cutting edge is penetrating the support, i.e. when the support is dilated. The penetration force F.sub.R acts, in the direction along the shaft, in the opposite direction of the penetration direction, on the injection needle.

(55) FIG. 7 is a graph illustrating how the penetration force F.sub.2, measured on an injection needle, is changing with an increased number of penetrations into a skin pad. FIG. 7 shows six curves showing penetration force measurements of the penetration force F.sub.2, from six different injection needles, each of which have penetrated the prepared skin pads of step 2 above, i.e. 0/100, 50/50, 75/25, 95/5, 100/0 (skin cream base/silicone), and the reference skin pad without any deposited lubricating composition.

(56) As can be seen in FIG. 7, after 10 penetrations, the injection needles which had penetrated the lubricated skin pads, i.e. 0/100, 50/50, 75/25, 95/5 and 100/0, are all showing a lower penetration force F.sub.2 compared to the injection needle which has penetrated the reference skin pad, i.e. without any lubrication. An effect may be seen at even lower numbers of penetrations, for example of the penetration force F.sub.2, of the injection needles which have penetrated the 100/0 and the 75/25 samples. 75/25 shows the lowest penetration force F.sub.2 overall and after 50 penetrations.

(57) FIG. 8 is a graph illustrating how the penetration force F.sub.R, measured on an injection needle, is changing with an increased number of penetrations into a skin pad. FIG. 8 shows six curves showing penetration force measurements of the penetration force F.sub.R from six different injection needles, each of which have penetrated the prepared skin pads of step 2 above, i.e. 0/100, 50/50, 75/25, 95/5, 100/0 (skin cream base/silicone), and the reference skin pad.

(58) As can be seen in FIG. 8, after 10 times used, the injection needles which had penetrated the lubricated skin pads, i.e. 0/100, 50/50, 75/25, 95/5 and 100/0, are all showing a lower penetration force, F.sub.R, compared to the injection needle which has penetrated the reference skin pad, i.e. without any lubrication. It is noticeable that all compositions containing silicone provided a lower penetration force, F.sub.R, than the composition without silicone above 10 penetrations. 75/25 shows the lowest penetration force, F.sub.R, overall and after 50 penetrations.

CONCLUSION

(59) By depositing a layer of a lubricating composition, according to the invention, on a skin pad, the penetration force (F.sub.2, F.sub.R) is significantly reduced when an injection needle is used multiple times for penetration at a single occasion.