HYDROPHILIC MEDICAL DEVICE ASSEMBLY

Abstract

A medical device assembly comprises a medical device, such as a urinary catheter, comprising an insertable part and a non-insertable part. The insertable part comprises an elongate shaft provided with a hydrophilic coating or surface. The assembly further comprises a wetting fluid compartment arranged to encircle at least a part of the medical device, and preferably at least a part of the non-insertable part, and an aqueous fluid arranged in the wetting fluid compartment. At least one of the aqueous fluid and the hydrophilic coating or surface comprises at least one surfactant. The hydrophilic coating or surface is maintained essentially separated from the aqueous fluid, and arranged to become wetted by movement of the elongate shaft through the wetting fluid compartment.

Claims

1. A medical device assembly comprising: a medical device comprising an insertable part and a non-insertable part, wherein the insertable part comprises an elongate shaft provided with a hydrophilic coating or surface; a wetting fluid compartment arranged to encircle at least a part of the medical device; and an aqueous fluid arranged in the wetting fluid compartment, wherein at least one of the aqueous fluid and the hydrophilic coating or surface comprises at least one surfactant; wherein the hydrophilic coating or surface is maintained essentially separated from the aqueous fluid, and arranged to become wetted by movement of the elongate shaft through the wetting fluid compartment.

2. The medical device assembly of claim 1, wherein the wetting fluid compartment is arranged to encircle at least a part of the non-insertable part of the medical device.

3. The medical device assembly of claim 1, wherein a total concentration of surfactant(s) is in the range of 0.001-1 wt % of a liquid phase.

4. The medical device assembly of claim 1, wherein a total concentration of surfactant(s) is in the range of 0.005-0.5 wt % of a liquid phase.

5. The medical device assembly of claim 1, wherein a total concentration of surfactant(s) is in the range of 0.01-1 wt % of a liquid phase.

6. The medical device assembly of claim 1, wherein a total concentration of surfactant(s) is in the range of 0.001-1 mM of a liquid phase.

7. The medical device assembly of claim 1, wherein a total concentration of surfactant(s) is in the range of 0.003-0.6 mM of a liquid phase.

8. The medical device assembly of claim 1, wherein the aqueous fluid further includes a polyol and/or a low molecular weight hydrophilic polymer.

9. The medical device assembly of claim 8, wherein the aqueous fluid includes a relative amount of polyol and/or low molecular weight hydrophilic polymer in the range of 0.01-20 wt %.

10. The medical device assembly of claim 8, wherein the aqueous fluid includes a relative amount of polyol and/or low molecular weight hydrophilic polymer in the range of 0.1-10 wt %.

11. The medical device assembly of claim 1, wherein the surfactant is a non-ionic surfactant.

12. The medical device assembly of claim 1, wherein the medical device is a catheter.

13. The medical device assembly of claim 1, wherein the medical device is a urinary catheter.

14. The medical device assembly of claim 1, further comprising a package accommodating the wetting fluid compartment and at least the insertable part of the medical device.

15. The medical device assembly of claim 1, wherein the wetting fluid compartment is fixedly arranged in the package, wherein extraction of the medical device from the package simultaneously provides a movement of the elongate shaft through the wetting fluid compartment, thereby wetting the hydrophilic coating or surface.

16. The medical device assembly of claim 1, wherein the wetting fluid compartment is releasable from the package.

17. The medical device assembly of claim 1, wherein the medical device is a catheter comprising at least one drainage opening arranged in a sidewall of the elongate shaft, wherein the wetting fluid compartment has a height in a longitudinal direction of the catheter exceeding a length of the drainage opening in the longitudinal direction of the catheter.

18. The medical device assembly of claim 1, wherein the medical device is a catheter comprising at least two drainage openings arranged in a sidewall of the elongate shaft, wherein the wetting fluid compartment has a height in a longitudinal direction of the catheter exceeding a length between the ends of the drainage openings being farthest apart in the longitudinal direction of the catheter.

19. The medical device assembly of claim 1, wherein at least one breakable seal is provided between the wetting fluid compartment and the elongate shaft.

20. The medical device assembly of claim 1, wherein two breakable seals are provided between the wetting fluid compartment and the elongate shaft, provided on opposite sides of the wetting fluid compartment.

21. The medical device assembly of claim 1, wherein the wetting fluid compartment comprises an amount of the aqueous fluid in the range of 0.5-5 ml.

22. The medical device assembly of claim 1, wherein the wetting fluid compartment comprises an amount of the aqueous fluid in the range of 1-4 ml.

23. The medical device assembly of claim 1, wherein the height of the level of wetting fluid within the wetting liquid compartment is at least 2 cm.

24. The medical device assembly of claim 1, wherein the height of the level of wetting fluid within the wetting liquid compartment is at least 4 cm.

25. A method for wetting a hydrophilic medical device comprising: providing a medical device comprising an insertable part and a non-insertable part, wherein the insertable part comprises an elongate shaft provided with a hydrophilic coating or surface; providing a wetting fluid compartment containing an aqueous fluid around at least a part of the non-insertable part, wherein at least one of the aqueous fluid and the hydrophilic coating or surface comprises at least one surfactant; and moving the elongate shaft in relation to the wetting fluid compartment, thereby wetting the hydrophilic coating/surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0090] For exemplifying purposes, the disclosed embodiments will be described in closer detail in the following with reference to embodiments thereof illustrated in the attached drawings, wherein:

[0091] FIG. 1 is a top view of a urinary catheter assembly in accordance with one embodiment of the present invention;

[0092] FIGS. 2A-D are cross-sectional views of the urinary catheter assembly of FIG. 1, showing various stages of an extraction and wetting process;

[0093] FIG. 3 is a top view of a urinary catheter assembly in accordance with another embodiment of the present invention; and

[0094] FIGS. 4A-E are cross-sectional view of the urinary catheter assembly of FIG. 3, showing various stages in an extraction and wetting process.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0095] In the following detailed description preferred embodiments of the invention embodiments 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.

[0096] A urinary catheter assembly 1 as illustrated in FIGS. 1 and 2A-D 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. The rear end 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.

[0097] 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.

[0098] The insertable section comprises an insertion tip, which may be a closed, rounded end. Further the insertable section may comprise drainage openings 23a, 23b, 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.

[0099] The insertable section may be 80-140 mm for a female user and 200-350 mm for a male user.

[0100] 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.

[0101] The catheter is accommodated in a package 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 package. The cavity is preferably sterile and moisture proof. To this end, the package may e.g. be made of a fluid impermeable material. However, materials having some permeability may also be used. The package is preferably, at least in most parts, made of a relatively flexible material, such as foil. The package may be transparent, but may alternatively be opaque or semi-opaque. The package may be in the form of a tube or hose. The package is preferably arranged to narrowly surround the catheter.

[0102] The package comprises an opening, preferably arranged above or overlying the non-insertable section 22 of the catheter. The opening may be a peel opening and/or tear opening. However, other openings may also be used, such as a cap, a lid or the like. When the package has been opened, the catheter is accessible, and the user may e.g. grip the non-insertable section and pull the catheter out of the package.

[0103] To allow convenient, clean and contamination free handling of the catheter, the assembly may further comprise an insertion aid 5. The insertion aid can be used as an aid when manipulating the catheter during or after having expelled the insertable section 21 out from the package for use.

[0104] The insertion aid 5 may, as in the illustrative examples, be arranged releasably connected to the non-insertable section 22 of the catheter. During use, the user may pull the insertion aid loose from the non-insertable section, and move it to any desired position along the length of the catheter shaft. However, in case the user does not wish to use the insertion aid, the insertion aid may be maintained in its original, non-released position during the entire use. The detachable connection between the insertion aid and the non-insertable section of the catheter may be realized in various ways, such as by friction fit, welding, adhesion, etc.

[0105] The insertion aid may be cylindrical, with a generally uniform diameter along its length. However, it may also have a slightly conical, flared shape, over its entire length or along part(s) of the length.

[0106] The insertion aid is preferably made of a relatively soft and flexible material, allowing the catheter to be gripped by applying a moderate finger pressure on the insertion aid. The insertion aid may be provided with a solid wall around its full circumference. However, the insertion aid may also comprise one or several slit openings, extending along the entire length of the insertion aid, or over only part(s) of the length. For example, a slit opening may extend from the distal end of the insertion aid, and towards the proximal end, over a length of e.g. ⅓ or ½ of the full length of the insertion aid. The tubular insertion aid is preferably made of a flexible plastics material.

[0107] The insertion aid may be used for catheter manipulation, thereby avoiding the need to directly touch the catheter, and in particular the insertable section of the catheter. This reduces the risk of contaminating the insertable section of the catheter prior to insertion. It may also be used to manipulate the catheter during and after withdrawal, thereby avoiding the risk of the user being contaminated by the used catheter.

[0108] Additionally, or alternatively, the wetting fluid compartment may also be used as an insertion aid, allowing indirect gripping and manipulation of the catheter.

[0109] The assembly further comprises a wetting fluid compartment 4 arranged to encircle at least a part of the non-insertable part. The wetting fluid compartment 4 comprises an aqueous fluid, capable of wetting the hydrophilic coating/surface of the catheter shaft.

[0110] The insertable section 21, and the hydrophilic coating/surface thereon, is maintained separated from the aqueous fluid in the storage position, as illustrated in FIGS. 1 and 2A. Upon use, the package is opened in the distal end, and as the catheter is being expelled, the hydrophilic coating/surface is pushed into and through the wetting fluid compartment 4, as illustrated in FIGS. 2B and 2C. When the catheter shaft has passed out from the wetting fluid compartment, as shown in FIG. 2D, the hydrophilic coating/surface has become wetted by the aqueous fluid, and any fluid remaining in the wetting fluid compartment at that time will pour out through the proximal opening and into the package. However, since a very limited amount of fluid needs to be used, the amount of remaining fluid will be very small.

[0111] In the embodiment illustrated in FIGS. 1 and 2A-D, the wetting fluid compartment 4 is fixedly arranged in the package 3, wherein extraction of the medical device from the package simultaneously provides a movement of the elongate shaft through the wetting fluid compartment, thereby wetting the hydrophilic coating/surface. In such an embodiment, the package is opened, and the medical device is expelled, as in conventional assemblies. As the medical device is expelled, the elongate shaft passes through the wetting fluid compartment, and is consequently completely wetted as soon as it has been removed from the package in a simple one-step procedure.

[0112] In an alternative embodiment, illustrated in FIGS. 3 and 4A-E, the wetting fluid compartment may be releasable from the package. Apart from this difference, the catheter assembly may be similar or identical to the above-discussed first embodiment.

[0113] In the embodiment of FIGS. 3 and 4A-E, the wetting fluid compartment 4′ is attached to the non-insertable section 22 of the catheter, e.g. in the same way as in the first discussed embodiment. However, the wetting fluid compartment 4′ is here not connected to the package. In the storage position, as shown in FIGS. 3 and 4A, the package is closed. Upon use, the package is opened in the distal end, and the catheter is expelled out from the package, as illustrated in FIG. 4B. The wetting fluid compartment remains attached to the catheter, and is pulled out from the package along with the catheter. In a subsequent step, illustrated in FIGS. 4C and 4D, the wetting fluid compartment 4′ is then moved in relation to the catheter shaft, so that it moves towards the proximal end. When the catheter shaft has been completely moved through the wetting fluid compartment, any remaining fluid will pour out from the wetting fluid compartment, and e.g. into a sink or a toilet.

[0114] In the same way as in the first discussed embodiment, the hydrophilic coating/surface will be activated and wetted as the catheter shaft is moved through the wetting fluid compartment, but in this second embodiment, this will be made in a step separate from the extraction of the catheter from the package.

[0115] In both the above-discussed embodiments, the wetting fluid compartment 4, 4′ may have a height in a longitudinal direction of the catheter exceeding a length of the drainage opening in the longitudinal direction of the catheter. If the catheter comprises at least two drainage openings 23a, 23b arranged in the sidewalls of the elongate shaft, as in the illustrative examples, the wetting fluid compartment 4, 4′ preferably has a height in a longitudinal direction of the catheter exceeding a length between the ends of the drainage openings being farthest apart in the longitudinal direction of the catheter. This is illustrated in detail in FIG. 2C, where the height of the wetting fluid compartment is shown as L1 and the distance between the ends of the drainage openings 23a and 23b being farthest apart is L2. Thus, here L1 is preferably greater than L2.

[0116] The wetting fluid compartment is arranged to encircle at least a part of the non-insertable part of the medical device. The wetting fluid compartment may e.g. be arranged to encircle a part of the catheter shaft not provided with a hydrophilic coating/surface, or a part provided with a hydrophilic coating/surface, but which is not intended for insertion. The wetting fluid compartment may also encircle a proximal part of a flared connector, or other part connected to the catheter shaft. In one embodiment, a proximal end of the wetting fluid compartment encircles a distal part of the catheter shaft and distal end of the wetting fluid compartment encircles a proximal end of the connector, such as in the illustrative examples of FIGS. 1 and 3.

[0117] The wetting fluid compartment may thus have a first, proximal opening and a second, distal opening. The openings are preferably closed by the non-insertable part of the medical device, ensuring that the wetting fluid does not escape from the wetting fluid compartment prior to withdrawal of the medical device through the wetting fluid compartment. Such closing can e.g. be obtained by a friction fit, whereby the inner diameters of the openings are essentially the same as the corresponding outer diameters of the non-insertable part at the positions where the openings are arranged.

[0118] In one embodiment, at least one breakable seal (not shown) is further provided between the wetting fluid compartment and the elongate shaft, and preferably two breakable seals, provided on opposite sides of the wetting fluid compartment. Thus, the seals are hereby preferably arranged between the inner surface of the openings and the corresponding outer surfaces of the non-insertable part. Such seals may e.g. be formed by an adhesive, rubber or the like.

[0119] Regardless of whether seals are used or not, the diameter of the proximal opening of the wetting fluid compartment is preferably essentially the same as the outer diameter of the elongate shaft, or only slightly greater.

[0120] At least the proximal opening of the wetting fluid compartment is preferably circular, and most preferably both the proximal and the distal openings are circular.

[0121] In an embodiment, the distal opening of the wetting fluid compartment has a greater diameter than the diameter of the proximal opening, such as illustrated in the embodiments of FIGS. 1 and 3. Here, the proximal opening of the wetting fluid compartment 4, 4′ has essentially the same inner diameter as the outer diameter of the catheter shaft, which it overlies. The distal opening of the wetting fluid compartment 4, 4′ overlies a part 24 of the non-insertable section 22, which has an outer diameter which is greater than the outer diameter of the catheter shaft. The distal opening of the wetting fluid compartment here has essentially the same inner diameter as the outer diameter of the part 24. Hereby, a slight distance may be formed between the elongate shaft and the distal opening when the elongate shaft is pulled out through the wetting fluid compartment.

[0122] Upon use, the medical device will be pulled in relation to the wetting fluid compartment, thereby breaking the seals, if such seals are present. However, since at least the proximal opening of the wetting fluid compartment is still essentially closed by the elongate shaft, the aqueous fluid will not pour out from the wetting fluid compartment during the withdrawal of the elongate shaft through the wetting fluid compartment. Due to capillary forces, the wetting fluid will instead be maintained in the compartment until the proximal tip of the elongate shaft has reached and passed through the proximal opening of the wetting fluid compartment. Any fluid remaining in the wetting fluid compartment will pour out only after complete removal of the elongate shaft, thus ensuring a complete wetting of the hydrophilic coating/surface.

[0123] To ensure that adequate wetting is obtained in the relatively short time during which each part of the hydrophilic coating/surface is exposed to the aqueous fluid, at least one of the aqueous fluid and the hydrophilic coating/surface includes at least one surfactant. In a preferred embodiment, the aqueous fluid includes the at least one surfactant. However, additionally or alternatively, the at least one surfactant may be included in the hydrophilic coating/surface.

[0124] The relative amount of surfactant of the fluid phase (the wetting fluid or the fluid in the wetted coating/surface) may be in the vicinity of the Critical Micelle Concentration for the surfactant(s).

[0125] The total concentration of surfactant(s) may be in the range of 0.001-1 wt %, of the fluid phase (the wetting fluid or the fluid in the wetted coating/surface) and preferably in the range 0.005-0.5 wt %, and more preferably in the range 0.01-0.1 wt %, and most preferably in the range 0.01-0.08 wt %.

[0126] Expressed in Molar (M), the total concentration of surfactant(s) may be in the range of 0.001-1 mM, of the liquid phase (the wetting fluid or the fluid in the wetted coating/surface) and preferably in the range 0.002-0.7 mM, and more preferably in the range 0.003-0.6 mM.

[0127] The surfactant is preferably water soluble, and may be non-ionic surfactant. However, other surfactants may also be used, such as zwitterionic, anionic or cationic. Further, the surfactant preferably has relatively large chains/molecules, which further reduces interaction with human tissue.

[0128] The aqueous fluid may further include a polyol, such as glycerol, and/or a low molecular weight hydrophilic polymer, such as PVP. In one embodiment, the aqueous fluid includes a relative amount of polyol/hydrophilic polymer in the range of 0.01-20 wt %, and preferably 0.05-15 wt %, and more preferably 0.1-10 wt %, and most preferably 1-8 wt %, such as about 5 wt %. The polyol/hydrophilic polymer provides protection for the wetting fluid, and in particular preserves the function of the surfactants, during radiation sterilization. The polyol/hydrophilic polymer reduces the crosslinking/reaction of the surfactant which may otherwise occur during radiation sterilization.

[0129] The aqueous fluid may further comprise an osmolality increasing compound, such as sodium chloride.

[0130] The aqueous fluid may also comprise a pH buffer, to ensure that the pH of the fluid is maintained in a preferred range, such as in the range of 4-8. The pH buffer may be citric acid, both other buffers may also be used, such as acetic acid, phosphate buffer, carboxylic acids, amino acids, aminosulphonic acids and inorganic acids.

[0131] The aqueous fluid preferably comprises at least 80 wt % water, and more preferably at least 90 wt %, and most preferably at least 95 wt %.

[0132] In embodiments where the aqueous fluid includes a low molecular weight polyol and/or hydrophilic polymer, the fluid preferably comprises 80-99 wt % water and 1-10 wt % polyol/hydrophilic polymer.

[0133] Preferably, the fluid contains primarily water, and optionally a polyol, such as glycerol, and/or a low molecular weight hydrophilic polymer, such as PVP. The total concentration of additives in addition to water and polyol/hydrophilic polymer, such as the surfactant, preferably is equal to or less than 5 wt %, and more preferably less than 3 wt %, and even more preferably less than 1 wt %, and most preferably less than 0.5 wt %. Apart from the surfactant, such additional additives may include one or more of an osmolality increasing agent, a pH buffer, an antibacterial agent, fragrances, a pharmaceutical active substance, or the like.

[0134] In the present solution, it is possible to use a very small volume of the aqueous fluid, since it is continuously applied to the hydrophilic coating/surface only where it is needed. Thus, it in principle suffice with a volume corresponding to the volume which is absorbed by the hydrophilic coating/surface for swelling of the same. In one embodiment, the wetting fluid compartment may comprise an amount of the aqueous fluid in the range of 0.5-5 ml, and preferably in the range of 1-4 ml. Such a small amount of wetting fluid will be sufficient for complete wetting of a hydrophilic coating/surface of a male urinary catheter.

[0135] The wetting fluid compartment is preferably impermeable to the wetting fluid, and preferably made of a gas impermeable material.

Experimental Results

[0136] The effect of using a surfactant in the wetting fluid has been demonstrated in a number of experiments. For the tests, four solutions were prepared as comparative examples (C1a-C1c and C2), and several solutions as example embodiments (E1-E10a). The following different wetting liquids were tested: [0137] C1: Plain water (as a comparative example) [0138] C1a: Water with 7 wt % glycerol (as another comparative example) [0139] C1b: Water with 7.5 wt % PVP K12 (as another comparative example) [0140] C2: Water with 2.5 wt % NaCl (as another comparative example) [0141] E1: Water with 0.077 wt % (0.5878 mM) Tween 80 [0142] E1a: Water with 0.076 wt % (0.5802 mM) Tween 80 and 7 wt % glycerol [0143] E2: Water with 0.019 (0.0152 mM) wt % Kolliphor p407 [0144] E2a: Water with 0.019 wt % (0.0152 mM) Kolliphor p407 and 7 wt % glycerol [0145] E3b: Water with 0.011 wt % (0.0088 mM) Kolliphor p407 and 7.5 wt % PVP K12 [0146] E4a: Water with 0.042 wt % (0.0420 mM) HPMC (Mn˜10,000/6 cP) and 7 wt % glycerol [0147] E5: Water with 0.010 wt % (0.0076 mM) Kolliphor p407 [0148] E6: Water with 0.005 wt % (0.0038 mM) Kolliphor p407 [0149] E7: Water with 0.019 wt % (0.1667 mM) Brij 35 [0150] E7a: Water with 0.019 wt % (0.1667 mM) Brij 35 and 7 wt % glycerol [0151] E8: Water with 0.019 wt % TEGO Betain F50 [0152] E8a: Water with 0.019 wt % TEGO Betain F50 and 7 wt % glycerol [0153] E9a: Water with 0.019 wt % Kolliphor p188 and 7 wt % glycerol [0154] E10a: Water with 0.018 wt % HPMC HME 4M and 7 wt % glycerol

[0155] For all the tests, LoFric® catheters from Wellspect have been used. The catheters were CH 14, with a length of 40 cm. Such catheters are commercially available, and have a hydrophilic coating comprising PVP, which obtains a low friction when wetted.

[0156] In a first line of experiments, the friction and wetting were evaluated manually. For these tests, a container comprising a liquid solution was arranged over the non-insertable section of the coated dry catheter, and an amount of wetting liquid was added to the container. The wetting liquid was maintained in the container when the catheter was manually drawn vertically up through the container at a high speed (about 30 cm/s) or a low speed (about 3 cm/s). The height of the liquid in the container that the catheters were drawn through, i.e. the liquid pillar height extending around the catheter, was either 2 cm or 7.5 cm. All the high speed tests were made with a 2 cm liquid height.

[0157] After having been pulled out through the container, the wetted catheters were hung vertically for a dry-out time of 90 s.

[0158] Thereafter, the slipperiness of the wetted hydrophilic coatings were assessed by pulling fingers along the shaft, and in particular to identify unevenness, such as presence of dry areas and areas with higher friction.

[0159] The assessed catheters were graded to be in one of the categories: [0160] 5: Very good [0161] 4: Good [0162] 3: OK [0163] 2: Several dry spots [0164] 1: Several large dry spots [0165] 0: No slipperiness

[0166] For some of the tests, the wetting liquid was radiation sterilized prior to wetting, and for others, the wetting liquid was not radiation sterilized.

[0167] The results of the manual assessment are presented in Table 1 below.

TABLE-US-00001 TABLE 1 Manual assessment of slipperiness Wetting Liquid Manual assessment Manual assessment solution Speed height Non-sterile Sterile C1 High 2 cm 1 0 C1a High 2 cm 1 1 C1b High 2 cm 2 0 C2 High 2 cm N/A 1 E1 High 2 cm 5 1 E1a High 2 cm 4-5 5 E2 High 2 cm 5 1 E2a High 2 cm 5 5 E3b High 2 cm 5 4-5 E4a High 2 cm 4-5 4-5 E2 Low 2 cm 3 N/A E2 Low 7.5 cm.sup.  4-5 N/A E5 High 2 cm 4 N/A E6 High 2 cm 2 N/A E6 Low 2 cm 1 N/A E6 Low 7.5 cm.sup.  3 N/A E7 High 2 cm 5 2 E7b High 2 cm 5 5 E8 High 2 cm N/A 2 E8a High 2 cm N/A 5 E8a Low 2 cm N/A 3 E9a High 2 cm N/A 5 E10a High 2 cm N/A 5

[0168] From this it can be deduced that all the comparative examples perform very poorly, and do not become adequately wetted by this wetting process.

[0169] All the inventive examples perform adequately, and are sufficiently wetted by the wetting process. It can be noted that too low addition of surfactant can lead to a somewhat poorer wetting—E2 at high speed performs better than E5, and much better than E6. It can also be noted that low speed does not make the performance better, but rather the opposite—E2 and E8a performs better at high speed. However, this can at least to some extent be compensated by having a greater liquid height—seen in E2 and E6.

[0170] It can also be noted that if the wetting liquid is sterilized by gamma or beta radiation, it may perform somewhat poorer after sterilization. See e.g. E1, E2 and E7. However, this can be effectively remedied by adding a polyol, such as glycerol, to the wetting liquid. See e.g. E1a, E2a, E4a, E8a, E9a and E10a. Addition of PVP in the wetting liquid also seems to have a similar protective effect—see e.g. E3b and E7b.

[0171] In another line of experiments, the water retention, or fluid dry out time, was tested. For these tests, the catheters were dipped very quickly, in 1-2 seconds, in a wetting liquid. Thereafter, the water retention/fluid dry out time of the catheters was determined by determining the water/fluid content (mg/cm.sup.2) in the hydrophilic coating after 1 and 6 minutes drying in air. The water/fluid content was determined by weighing the catheters before wetting, to obtain a reference weight, and to weigh the catheters 1 and 6 minutes after wetting, and subtracting the reference weight from this measurement. The area of coating is measured. The obtained weight/cm.sup.2 difference is a measure on the water/fluid content being held by the hydrophilic coating at the time of measurement.

[0172] A number of different wetting liquids were tested. Each of the wetting liquids was tested multiple times, and the presented results are the average values. The results are presented in Table 2 below.

TABLE-US-00002 TABLE 2 Water retention/fluid dry out time in coating after 1 and 6 minutes Water retention Water retention Wetting Radiation after 1 minute after 6 minutes solution sterilized [mg/cm2] [mg/cm2] C1 No 8.39 6.53 C1a No 7.96 6.40 C1a Yes 8.35 6.61 C1b No 7.05 5.21 E1 No 10.74 8.75 E1 Yes 9.04 6.94 E1a Yes 10.48 8.60 E2 No 10.18 8.19 E2 Yes 8.65 6.80 E2a Yes 10.73 8.90 E3b Yes 9.21 7.39 E5 No 10.79 8.70 E6 No 10.41 8.56 E7 No 10.93 8.77

[0173] From this it can be deduced that all the inventive examples perform better than the comparative examples, both after 1 minute and 6 minutes. It can also be noted that when radiation sterilization has been used, the wetting liquids having an addition of glycerol and/or PVP perform better.

[0174] The slipperiness of the catheters was, as discussed in the foregoing, evaluated by manual assessment. However, in order to confirm this, some of the samples were evaluated using a Harland FTS Friction Tester, available from Harland Medical Systems, with a clamp force of 100 g. To this end, the catheters were dipped in a wetting liquid, and immediately pulled out by the friction tester during continuous measurement of the friction. The first part of the catheters pulled out and measured were disregarded, since these parts were not wetted. The measured parts were wetted about 1-2 seconds.

[0175] The results of this are presented in the Table 3 below.

TABLE-US-00003 TABLE 3 Coefficient of friction results Wetting Friction solution coefficient C1 1.72 E2 0.33 E7 0.65

[0176] These results confirm the above-discussed findings, and both E2 and E7 have much lower friction than the comparative example C1.

[0177] In further experiments it has been found that the pH of the wetting liquid is generally not affected by the addition of the surfactant.

Concluding Remarks

[0178] 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 different surfactants can be used, and in various concentrations. Further, other additives, such as polyol and/or a low molecular weight hydrophilic polymer, may be beneficial in certain circumstances, but may not be necessary in other.

[0179] The arrangement of the wetting liquid compartment to enable withdrawal of the catheter shaft through the compartment may be accomplished in many different ways. Further, the teachings described in connection with examples embodiments are not only of advantage for urinary catheters, but also for many other types of hydrophilic catheters and hydrophilic medical devices.

[0180] 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.