METHOD FOR STERILIZING A MEDICAL DEVICE

Abstract

A method of producing a ready-to-use medical device with a functional coating includes the steps of bringing the medical device, at least with its functional coating, in contact with a composition which prevents or retards degradation of the functional coating and sterilizing the medical device and the composition via radiation. A method leads to an improved product, namely an improved ready-to-use medical device which does not suffer a loss of quality during sterilization and storage. The composition comprises carboxymethyl cellulose or a derivative or salt thereof and/or an antioxidant selected from gallic acid or a derivative thereof.

Claims

1. A method of producing a ready-to-use medical device with a functional coating, comprising: bringing the medical device, at least with its functional coating, in contact with a composition which prevents or retards degradation of the functional coating; and sterilizing the medical device and the composition via radiation, wherein the composition comprises carboxymethyl cellulose or a derivative or salt thereof and/or an antioxidant selected from gallic acid or a derivative thereof.

2. The method according to claim 1, wherein the antioxidant of the composition is an ester, amide or oxadiazole derivative of gallic acid.

3. The method according to claim 1, wherein gallic acid or a derivative thereof is present in the composition in an amount of 0.001% to 5% by weight based on the total weight of the composition.

4. The method according to claim 1 wherein the composition comprises the sodium salt of carboxymethyl cellulose.

5. The method according to claim 1, wherein carboxymethyl cellulose or a derivative or salt thereof is present in an amount of 0.1% to 10% by weight based on the total weight of the composition.

6. The method according to claim 1, wherein the composition comprises carboxymethyl cellulose or a derivative or salt thereof and gallic acid or a derivative thereof selected from an ester, amide or oxadiazole derivative of gallic acid, preferably propyl gallate.

7. The method according to claim 6, wherein gallic acid or a derivative thereof is present in an amount of 0.001% to 1% by weight, based on the total weight of the composition.

8. The method according to claim 1, wherein the composition comprises a solution enhancer.

9. The method according to claim 1, wherein the composition further comprises an aqueous or oil based base solution or a lipid media or a combination thereof.

10. The method according to claim 9, wherein the aqueous base solution of the composition is selected from distilled water, deionized water, reverse osmosis water, filtered water or a saline solution.

11. The method according to claim 9, wherein the aqueous base solution is present in the composition in an amount of 50% to 99.99% by weight based on the total weight of the composition.

12. The method according to claim 1, wherein the composition further comprises a stabilizer and/or a buffer solution.

13. The method according to claim 1, wherein the solution enhancer is selected from ethylene glycol, diethylene glycol, propylene glycol, or glycerol and is present in an amount of 0.1% to 49.8% by weight based on the total weight of the composition.

14. The method according to claim 12, wherein the buffer solution has a pH of from 2.0 to 7.4.

15. The method according to claim 1, wherein the energy dose of radiation during radiation sterilization is in a range from 1 kGy to 50 kGy, preferably 15 kGy to 45 kGy, more preferably 25 kGy to 45 kGy.

16. The method according to claim 1, further comprising: providing the medical device; coating the medical device at least in parts with the functional coating; activating the functional coating of the medical device by bringing it into contact with the composition which prevents or retards degradation of the functional coating, and; packing the medical device and the composition into a vapour-tight package.

17. The method according to claim 1, wherein the medical device is a catheter.

18. The method according to claim 17, wherein the functional coating is a hydrophilic coating.

19. The method according to claim 18, wherein the catheter comprises a catheter shaft which is coated with the hydrophilic coating at least along its insertable length and which is tightly surrounded by a retractable sleeve and wherein the retractable sleeve and/or the catheter have a liquid-tight closure at a distal end and at a proximal end so that any liquid present in the retractable sleeve or the catheter shaft remains within the retractable sleeve and the catheter as long as the liquid-tight closure is not broken.

20. (canceled)

Description

[0156] In the following, a ready-to-use medical device with a functional coating which is produced with the method of the present invention and the method itself are described in more detail with the aid of drawings:

[0157] FIG. 1 shows a first embodiment of the ready-to-use medical device produced with the method of the present invention,

[0158] FIG. 2 shows a detail of the medical device of FIG. 1,

[0159] FIG. 3 shows a second embodiment of a ready-to-use medical device produced with the method of the present invention, and

[0160] FIG. 4 shows a detail of the medical device of FIG. 3.

[0161] In FIG. 1 a first embodiment of a ready-to-use medical device produced with the method of the present invention is shown. The ready-to-use medical device of the first embodiment is a catheter 1 used for intermittent catheterization. The catheter 1 comprises a catheter shaft 2 with a catheter tip 3 at a distal end 5 and a funnel 4 at a proximal end 6. The catheter shaft 2 is covered with a hydrophilic coating at least along its insertable length. The catheter shaft 2 is surrounded by a retractable sleeve 7. At the proximal end 6, the retractable sleeve 7 is fixed to the catheter shaft 2. The retractable sleeve can also be fixed to the funnel. At the distal end 5, the catheter 1 is provided with an introduction aid 8. The introduction aid 8 is slidably arranged on the catheter shaft 2. That means that the introduction aid 8 can be slid up and down the catheter shaft without any effort. The distal end of the retractable sleeve 7 is fixed to the introduction aid 8. A plug 9 can be inserted in the end of the introduction aid 8 that faces away from the catheter shaft 7 so that a fluid-tight connection or closure between the plug 9 and the introduction aid 8 is formed. The plug 9 preferably has a T-shape. Furthermore, the plug 9 can comprise a reservoir with a wetting agent which comprises the composition as described above. The funnel 4 comprises a cap 10 which is connected to the funnel 4 via a hinge 11. The distal end 6 of the catheter 1 with the funnel 4 and the cap 10 is shown in more detail in FIG. 2. For clarity reasons, the sleeve is not shown in FIG. 2. The cap 10 is plugged in the funnel 4 so that a liquid-tight closure is achieved. The wetting agent is inserted into the retractable sleeve 7 via the plug 9. Because the plug 9 and the introduction aid 8 as well as the funnel 4 and the cap 10 form liquid-tight closures, the wetting agent remains inside the retractable sleeve 7 and/or the catheter shaft 2 and the outside of the retractable sleeve 7 as well as the outside of the funnel 4 remain dry and can be easily gripped by a user. This catheter set can then be placed in a vapour-tight package (not shown).

[0162] FIG. 3 shows a second embodiment of a ready-to-use medical device produced with the method of the present invention. In the second embodiment, the ready-to-use medical device is also a catheter 21 used for intermittent catheterization. The catheter 21 comprises a catheter shaft 22 which is provided with a catheter tip 23 at a distal end 25 and with a funnel 24 at a proximal end 26. The catheter shaft 2 is covered with a hydrophilic coating at least along its insertable length. The catheter shaft 22 is enclosed by a retractable sleeve 27. The proximal end of the retractable sleeve 27 is connected to the proximal end 26 of the catheter 21. The retractable sleeve 27 can either be fixed directly to the catheter shaft 22 or to the funnel 24. The distal end 29 of the retractable sleeve 27 is connected to an introduction aid 28 which is slidably arranged on the catheter shaft 22. The introduction aid 28 is pushed back on the catheter shaft 22 so that the retractable sleeve 27 is retracted and the catheter shaft 22 is exposed. The catheter 21 with the catheter shaft 22 and the retractable sleeve 27 arranged thereon is arranged in a vapour-tight package 30. Furthermore, a wetting agent comprising the composition as described above is inserted in the package 30.

[0163] In both embodiments, the catheter shaft 2, 22 is coated with a hydrophilic coating, the functional coating, at least along its insertable length. The insertable length of the catheter shaft 2, 22 is the length of the catheter shaft which is inserted in the urethra when the catheter is used. Furthermore, in both embodiments, the wetting agent contacts and activates the hydrophilic coating of the catheter shaft 2, 22. The wetting agent comprises the composition as described above with carboxymethyl cellulose or a derivative or a salt thereof and/or an antioxidant selected from gallic acid or a derivative thereof as described above.

[0164] In the following, a method for a producing the catheters 1, 21 as shown above is described. In a first step, the catheter shaft 2, 22 with the catheter tip 3, 23 and the funnel 4, 24 is produced. After that, the catheter shaft 2, 22 is coated with a hydrophilic coating. The retractable sleeve 7, 27 is arranged around the catheter shaft 2, 22 and is connected to the catheter shaft 2, 22 or the funnel 4, 24 at the proximal end of the catheter 1, 21. At the distal end of the catheter 1, 21 an introduction aid 8, 28 is slidably arranged on the catheter shaft 2, 22 and connected to the distal end of the retractable sleeve 7, 27.

[0165] In the first embodiment, the funnel 4 is closed with the cap 10 and the plug 9 with the wetting agent contained therein is connected to the introduction aid 8. The complete assembly is then placed in a vapour-tight package (not shown). The wetting agent comprises the composition as described above. The wetting agent is brought into contact with the hydrophilic coating of the catheter shaft 2 so that the hydrophilic coating is activated. The complete package is then submitted to radiation, for example -irradiation (see page 1, second to last paragraph), so that all components are sterilized. Because the wetting agent comprises a composition as described above, degradation of the hydrophilic coating during sterilization and storage is avoided.

[0166] In the second embodiment, the catheter 21 comprising the catheter shaft 22, the catheter tip 23, the funnel 24 and the retractable sleeve 27 is placed in a vapour-tight package 30. The funnel 24 and the introduction aid 8 are open. Furthermore, the wetting agent comprising the composition as described above is added to the package 30. The wetting agent is brought into contact with a hydrophilic coating of the catheter shaft 22 so that the hydrophilic coating is activated. After that, the entire package is submitted to radiation sterilization, for example -irradiation, so that all components are sterilized.

[0167] In both embodiments, the energy dose of radiation during radiation sterilization lies in a range from 1 kGy to 50 kGy, preferably 15 kGy to 45 kGy, more preferably 25 kGy to 45 kGy.