REUSABLE HYDROPHILIC URINARY CATHETER ASSEMBLY

Abstract

A reusable urinary catheter assembly comprises a storage container defining a cavity, a hydration liquid and a reusable urinary catheter. The hydration liquid includes a disinfection medium and a hydrophilic polymer. The viscosity of the hydration liquid is 40 cP or lower. The reusable urinary catheter includes a shaft, and at least a part of the shaft is provided with a hydrophilic surface. During storage, the shaft is enclosed within the cavity in a storage position. The hydration fluid hydrates and regenerates the hydrophilic surface and disinfects the catheter. The catheter is configured to be repeatedly inserted into and removed from the storage container.

Claims

1. A reusable urinary catheter assembly, comprising: a storage container defining a cavity; a hydration liquid within the cavity, the hydration liquid comprising a disinfection medium and at least one hydrophilic polymer, and wherein a viscosity of the hydration liquid is 40 cP or lower; a reusable urinary catheter including a shaft, wherein at least a part of the shaft is provided with a hydrophilic surface, the shaft being enclosed within the cavity in a storage position, wherein the hydration fluid hydrates and regenerates the hydrophilic surface and disinfects the reusable urinary catheter, the reusable urinary catheter being configured to be repeatedly inserted into and removed from the storage container.

2. The reusable urinary catheter assembly of claim 1, wherein the at least one hydrophilic polymer comprises at least one of polyvinyl pyrrolidone (PVP), polyvinyl alcohol (PVA), polyethylene oxide (PEO) or hydroxypropyl methylcellulose (HPMC).

3. The reusable urinary catheter assembly of claim 1, wherein the at least one hydrophilic polymer comprises PVP.

4. The reusable urinary catheter assembly of claim 3, wherein the PVP has a molecular weight in one of the following ranges: 2-2000 kg/mol, 30-1800 kg/mol, or 40-1700 kg/mol.

5. The reusable urinary catheter assembly of claim 3, wherein the PVP has a molecular weight in the range of 40-80 kg/mol, and wherein a concentration of PVP in the hydration liquid is in the range of 5-20 wt %.

6. The reusable urinary catheter assembly of claim 3, wherein the PVP has a molecular weight in the range of 40-80 kg/mol, and wherein a concentration of PVP in the hydration liquid is in the range of 10-16 wt %.

7. The reusable urinary catheter assembly of claim 3, wherein the PVP has a molecular weight in the range of 1000-1700 kg/mol, and wherein a concentration of PVP in the hydration liquid is in the range 1.0-5.0 wt %.

8. The reusable urinary catheter assembly of claim 3, wherein the PVP has a molecular weight in the range of 1000-1700 kg/mol, and wherein a concentration of PVP in the hydration liquid is in the range 2.0-3.0 wt %.

9. The reusable urinary catheter assembly of claim 1, wherein a concentration of the at least one hydrophilic polymer in the hydration liquid is at least 0.25 wt %.

10. The reusable urinary catheter assembly of claim 1, wherein a concentration of the at least one hydrophilic polymer in the hydration liquid is at least 1.0 wt %.

11. The reusable urinary catheter assembly of claim 1, wherein the viscosity of the hydration liquid is 30 cP or lower.

12. The reusable urinary catheter assembly of claim 1, wherein the viscosity of the hydration liquid is 20 cP or lower.

13. The reusable urinary catheter assembly of claim 1, wherein the viscosity of the hydration liquid is in the range of 2-40 cP.

14. The reusable urinary catheter assembly of claim 1, wherein the viscosity of the hydration liquid is in the range of 7-20 cP.

15. The reusable urinary catheter assembly of claim 1, wherein the disinfection medium comprises a chemical disinfectant.

16. The reusable urinary catheter assembly of claim 15, wherein the chemical disinfectant comprises at least one of: benzalkonium chloride (BAC), sodium hypochlorite, silver nitrate, povidone-iodine (PVP-iodine) or triclosan.

17. The reusable urinary catheter assembly of claim 1, wherein the disinfection medium comprises benzalkonium chloride BAC.

18. The reusable urinary catheter assembly of claim 1, wherein the hydration liquid further comprises a surfactant.

19. The reusable urinary catheter assembly of claim 18, wherein a total concentration of the surfactant is in the range of 0.01-0.5 wt %.

20. The reusable urinary catheter assembly of claim 18, wherein the surfactant is a non-ionic surfactant.

21. A method for preparing a reusable hydrophilic urinary catheter for repeated use, the method comprising: inserting a hydration liquid into a cavity of a storage container, the hydration liquid comprising a disinfection medium and at least one hydrophilic polymer, and wherein a viscosity of the hydration liquid is 40 cP or lower; and inserting the reusable hydrophilic urinary catheter into the storage container, before or after insertion of the hydration liquid, wherein the hydration liquid hydrates and regenerates a hydrophilic surface of the reusable hydrophilic urinary catheter and disinfects the reusable hydrophilic urinary catheter.

22. A hydration liquid for regeneration, disinfection and activation of a reusable hydrophilic urinary catheter, wherein the hydration liquid is an aqueous liquid comprising a disinfection medium and at least one hydrophilic polymer, wherein a concentration of hydrophilic polymer in the hydration liquid is at least 0.25 wt %, and wherein a viscosity of the hydration liquid is 40 cP or lower.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0063] For exemplifying purposes, the disclosed technology will be described in closer detail in the following with reference to embodiments thereof illustrated in the attached drawing, wherein:

[0064] FIG. 1 is a cross-sectional view of a reusable urinary catheter assembly in accordance with an example embodiment.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0065] In the following detailed description preferred embodiments of the disclosed technology are exchangeable between the embodiments and may be combined in different ways, unless anything else is specifically indicated. It may also be noted that, for the sake of clarity, the dimensions of certain components illustrated in the drawings may differ from the corresponding dimensions in real-life implementations of the invention, e.g., the length of the medical device, etc. Still further, even if the detailed discussion in the following relates to a urinary catheter assembly, it is to be acknowledged that the same principles may be used for assemblies also for other hydrophilic catheters, as well as for assemblies for other hydrophilic medical devices.

[0066] A urinary catheter assembly 1 as illustrated in FIG. 1 comprises a catheter 2 having an insertable section 21, comprising an insertable, proximal part, with an insertion tip, on a catheter shaft, and a non-insertable section 22, a distal part, forming a connector part. The non-insertable section 22 preferably has a larger diameter than the insertable section 21 at least on a part thereof (see, e.g., section 24). The rear end 5 of the non-insertable section may be flared or funnel-shaped, and may be arranged to be connected to a tapered connection part of a urine collection bag or the like. However, the non-insertable section may alternatively have a relatively uniform cross-sectional area.

[0067] At least a part of the insertable section 21 forms an elongate shaft with an insertable length to be inserted into a natural or artificial body opening of a user, such as into a urethra of the user.

[0068] The insertable section comprises an insertion tip, which may be a closed, rounded end. Further the insertable section may comprise one or several drainage openings 23, arranged in the vicinity of the insertion tip, so called catheter eyes or eyelets, leading into a lumen extending through the catheter, and into a discharge outlet arranged at the rearward end of the non-insertable section 22.

[0069] The insertable section may be 80-140 mm for a female user and 200-350 mm for a male user.

[0070] The insertable section 21 may comprise a hydrophilic coating/surface, and form a hydrophilic catheter, as is per se well known in the art. The hydrophilic coating/surface may be in the form of a hydrophilic coating, for example PVP, and which provides a low-friction surface when wetted with a wetting fluid. Even though PVP is the preferred hydrophilic material, other hydrophilic materials may be used, as exemplified in the foregoing.

[0071] The catheter is intended for repeated use, and between the use periods, the catheter is intended to be stored in a storage container, so that at least the insertable part of the catheter is in contact with a hydration liquid. The hydration liquid serves to activate and regenerate the hydrophilic surface of the catheter, and also to disinfect the catheter for a subsequent new use.

[0072] In the storage position, the catheter is accommodated in a storage container 3, forming a closed cavity in which at least the insertable section of the catheter is arranged. In the illustrative examples, the entire catheter is arranged within the storage container. The cavity is preferably impermeable to the hydration liquid. The storage container is preferably, at least in most parts, made of a relatively rigid material. However, the storage container may also be made of a flexible material, such as foil. The storage container may be transparent, but may alternatively be opaque or semi-opaque. The storage container may be in the form of a tube or hose, a bottle, a case, or the like. The storage container is preferably arranged to surround the catheter relatively narrowly.

[0073] The storage container may e.g. be made of a material such as PVC plastics and high density polyethylene (HDPE). However, other materials are also feasible. For example, many other polymer materials and composite materials are feasible. The container may also comprise fibers, such as a fiber based material. Further, many other types of materials may also be used, in particular for embodiments where the storage container should be reused many times, and for many catheters. For such embodiments in particular, the storage container can be made of more durable, and possibly more rigid materials, which are easier to wash and clean, such as metal, glass, ceramics, and the like.

[0074] The storage container may be arranged to receive the catheter in a relatively straight configuration. However, alternatively, the storage container may be arranged to accommodate the catheter in a curved or bent configuration, to provide a more compact storage container.

[0075] The storage container may comprise an opening, preferably arranged above or overlying the non-insertable section 22 of the catheter. The opening may be provided with a closure 31, such as a cap or a lid. The closure may be connected to the opening by means of a thread, a friction fit, or the like. The closure can, thus, be removed to open the opening, for extraction of the catheter for use, and then again be closed when the catheter has been used, and then reinserted into the storage container.

[0076] The closure can, e.g., be made of a relatively rigid material, such as a polymeric material, and preferably closes off the opening so that when the catheter is stored in the storage container, hydration liquid does not leak from the opening.

[0077] During use, the storage container is at least partly filled with the above-discussed hydration liquid 4 arranged to encircle and immerse at least a part of the insertable part when the catheter is arranged in the storage container, and preferably at least the whole insertable part.

[0078] The catheter can be inserted into and removed from the storage container repeatedly, for repeated use of the catheter.

[0079] As discussed in the foregoing, the hydration liquid comprises water, to wet and activate the hydrophilic surface of the catheter, a hydrophilic polymer, arranged to regenerate the hydrophilic surface of the catheter between use periods, and a disinfection medium, to disinfect, and possibly sterilize, the catheter before the next use.

[0080] In embodiments, the hydration liquid may also comprise other additives, such as surfactant(s), osmolality increasing agent(s), pH buffer(s), etc.

EXPERIMENTAL RESULTS

[0081] In the following, some experimental tests will be discussed.

[0082] In a first line of experiments, the viscosity at 25 degrees Celsius of the hydration liquid was evaluated. Here, hydration liquids containing various concentrations of a hydrophilic polymer were used. The hydrophilic polymer used for these tests was PVP K30, having a molecular weight of 40-80 kg/mol. The hydrophilic polymer was mixed with water with a magnetic stirrer. The viscosity of the liquids was determined with a viscometer. The hydration liquid was then used as a storage liquid for the hydrophilic urinary catheters. The hydration liquid was arranged in a storage container together with a urinary catheter. The urinary catheters were then removed from the hydration liquid, and the friction and feel of the catheter surface were evaluated manually. It was found that conventional friction measurements could not be used, since the liquid remaining on the surface gave misleading results. Instead, the friction and feeling of the catheters were evaluated manually, by experienced testers. The manual feel of the catheter surfaces was evaluated immediately after removal from the storage container, and also after having scraped off excess liquid from the surface. The viscosity, concentration and manual evaluation of the different PVP solutions are shown in Table 1.

TABLE-US-00001 TABLE 1 The viscosity of the PVP K30 solutions with varying polymer concentration. PVP K30 concentration Viscosity Manual evaluation Manual evaluation Sample (%) (cP) before scraping after scraping 1 5 2.6 Good Good 2 10 5.6 Good Good 3 15 11.9 Good, but small amount Good of liquid remaining 4 18 17.8 Good, but liquid remaining Good 5 21 28.1 Acceptable, but much Acceptable, but liquid liquid remaining still remaining 6 25 47.2 Acceptable, but much Poor, and liquid liquid remaining remaining 7 30 94.1 Not acceptable, very Poor, and liquid much liquid remaining remaining 8 35 195 Not acceptable, very Very poor, and much liquid remaining liquid remaining 9 40 534 Not acceptable, very Very poor, and much liquid remaining liquid remaining 10 45 1067 Not acceptable, very Very poor, and much liquid remaining liquid remaining

[0083] Thus, it has been found that the viscosity increases rapidly and exponentially when the concentration of the hydrophilic polymer increases. Roughly, the viscosity doubles for every 5% increment in PVP K30 concentration.

[0084] From the evaluations it may be concluded that a hydration liquid having a viscosity of at most 40 cP is acceptable, but even better results are achieved when the viscosity is 30 cP or lower, and preferably 25 cP or lower, and more preferably 20 cP or lower, and most preferably 15 cP or lower. It may also be concluded that the viscosity of the hydration liquid should preferably be in the range of 2-40 cP, and preferably 5-30 cP, and more preferably 7-20 cP, and more preferably 10-15 cP, and most preferably 11-13 cP.

[0085] In another line of tests, different hydrophilic polymers were tested to evaluate their suitability for use in a hydration liquid to regenerate a hydrophilic surface of a urinary catheter after use. The catheters were stored in the different hydration liquids between uses, and were a number of times a day removed and tested. The tests were made manually, simulating the abrasion occurring during an insertion into a real urethra, and the feel and slipperiness of the catheter were evaluated. As a benchmark, the manually evaluated feel of a commercially available LoFric® catheter was used. The catheters were each time graded from 9-1, where 9 was equal to the feel of the benchmark catheter. The grades 9-7 was considered very good, 6-4 to be acceptable, and grades 3-1 to be poor, and unfit for use as a urinary catheter. The results of these measurements are shown in Table 2 below.

TABLE-US-00002 TABLE 2 Manual evaluation of friction during repeated use. Average molecular Number of Number of weight of use times use times Concentration additive of at least of at least Additive (%) (kg/mol) grade 9-7 grade 6-4 PEO 4.38 100 19 22 HPMC 4.0 10 15 19 PVA 2.79 166 19 23 PVP K12 34 2.5 16 19 PVP K30 15 49 20 23 PVP K90 2.52 1050 20 23 Glycerol 64.5 0.092 4 8 No additive N/A N/A 8 13

[0086] The concentrations of the additives were all chosen to provide a viscosity within the preferred range of 11.5-12 cP. It was found that hydrating liquids comprising hydrophilic polymers provided a prolonged durability of the catheters, thereby making them better suited for use with reusable catheter, compared to hydrating fluids comprising e.g. glycerol or without additives.

[0087] From this it may be concluded that all the examples having been immersed in a hydration liquid comprising a hydrophilic polymer between uses were significantly better for repeated use than when immersed in plain water or water with other additives, such as glycerol. It is believed that the hydrophilic polymer in the hydration liquid regenerates the hydrophilic surface of the catheter after each use, thereby making it better for subsequent use. The regeneration seems to be especially good when different types of PVP is used, but also for PVA and PEO.

[0088] In another line of experiments, hydration liquids with different concentrations of some of the hydrophilic polymers were evaluated. Again, the catheters were stored in the different hydration liquids between uses, and were a number of times a day removed and tested. The tests were made manually, simulating the abrasion occurring during an insertion into a real urethra, and the feel and slipperiness of the catheter were evaluated. As a benchmark, the manually evaluated feel of a commercially available LoFric® catheter was used. The catheters were each time graded from 9-1, where 9 was equal to the feel of the benchmark catheter. The grades 9-7 was considered very good, 6-4 to be acceptable, and grades 3-1 to be poor, and unfit for use as a urinary catheter. The results of these measurements are shown in Table 3 below.

TABLE-US-00003 TABLE 3 Manual evaluation of friction during repeated use. Average molecular Number of Number of weight of use times use times Concentration additive of at least of at least Additive (%) (kg/mol) grade 9-7 grade 6-4 PVP K12 15 2.5 9 11 PVP K12 34 2.5 16 19 PVP K30 2 49 9 12 PVP K30 5 49 10 14 PVP K30 15 49 20 >23 PVP K90 0.25 1050 11 16 PVP K90 0.5 1050 11 15 PVP K90 1.0 1050 14 21 PVP K90 2.52 1050 20 23 PVP K12 + 5/10  2.5/49 >23 >23 K30 PVP K30 + 15/0.01 49 >23 >23 surfactant Glycerol 64.5 0.092 4 8 No additive N/A N/A 8 13

[0089] From this it may be concluded that all the examples having been immersed in a hydration liquid comprising a hydrophilic polymer between uses were significantly better for repeated use than when immersed in plain water or water with other additives, such as glycerol. It was found that higher concentrations of hydrophilic polymer in the hydration liquid improved regeneration, and thus improved the possibilities of repeated use. It is therefore believed that a balance need to be found between as high as possible concentration of hydrophilic polymer to improve regeneration, and to keep the concentration of hydrophilic polymers sufficiently low to avoid too high viscosity.

[0090] It was further found that a mix of PVP having different molecular weights could be beneficial.

[0091] It was further found that an addition of a small amount of surfactant can be used, and would further improve the regeneration properties of the hydration liquid.

[0092] In another line of experiments, hydration liquids with different types of disinfection mediums were used, and evaluated in respect of the disinfection effect. The hydration liquid comprised 5 wt % of PVP K30, and various disinfection mediums. As comparative examples, a hydration liquid with PVP K30 but without any disinfection medium was used, as well as a hydration liquid only comprising water.

[0093] For the tests, catheters were first activated in a hydration liquid containing a disinfectant. Thereafter, the catheters were immersed in an E. coli suspension. The catheters were then rinsed in plain water, before again being immersed in the same hydration liquid used for the activation for 4 hours. Thereafter, the catheters were transferred into a growth medium and incubated at 37 deg. C. for 19.5 hours. After this, it was determined whether, or not, bacterial growth had occurred during incubation. The results of these measurements are shown in Table 4 below.

TABLE-US-00004 TABLE 4 Manual evaluation of friction during repeated use. Concentration of disinfection medium Result after Disinfection medium (wt %) incubation Benzalkonium chloride 0.025 No growth Benzalkonium chloride 0.1 No growth Sodium hypochlorite 0.02 No growth Silver nitrate 0.05 No growth Silver nitrate 0.2 No growth PVP-iodine 1 No growth PVP-iodine 5-7.5 No growth Triclosan 0.075 No growth Triclosan 0.3 No growth Control - water + PVP K30 — Growth Control - only water — Growth

[0094] These measurements showed that all the tested disinfection mediums were effective to reduce bacterial growth, and thereby to sterilize the catheters in a limited time. The control experiments show that in case no disinfection medium is used, a bacterial growth will occur.

CONCLUDING REMARKS

[0095] Specific embodiments of the invention have now been described. However, several alternatives are possible, as would be apparent for someone skilled in the art. For example, many other hydrophilic polymers than the ones mentioned above may be used, as well as other disinfecting mediums, etc. Further, other additives, such as surfactants, can be used, and in various concentrations. Such other additives may be beneficial in certain circumstances, but may not be necessary in other.

[0096] Such and other obvious modifications must be considered to be within the scope of the present invention, as it is defined by the appended claims. It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting to the claim. The word “comprising” does not exclude the presence of other elements or steps than those listed in the claim. The word “a” or “an” preceding an element does not exclude the presence of a plurality of such elements. Further, a single unit may perform the functions of several means recited in the claims.