Reusable hydrophilic urethral catheter assembly

Abstract

The reusable urinary catheter assembly includes a storage container defining a cavity, a hydration liquid, and a reusable urinary catheter. The hydration liquid includes a disinfecting medium and a hydrophilic polymer, and the viscosity of the hydration liquid is 40 cP or less. The reusable urinary catheter includes a shaft, at least a portion of the shaft being provided with a hydrophilic surface. During storage, the shaft is enclosed within the cavity in a storage position, and the hydration liquid hydrates and regenerates the hydrophilic surface to disinfect the catheter. The catheter is configured to be repeatedly inserted into and removed from the storage container.

Description

Technical Field

[0001] The present invention relates to a reusable urethral catheter assembly. The present invention also relates to a method of creating a reusable hydrophilic urethral catheter for further use, and a hydration solution for the regeneration, disinfection and activation of a reusable hydrophilic urethral catheter.

Background Art

[0002] The present invention relates to a urethral catheter assembly. Urethral catheters are commonly used to drain urine from the bladder. Urethral catheters can be indwelling for long-term use, such as for several days or weeks, or for intermittent use, whereby the catheter is typically used for a single drainage procedure that lasts for several minutes. Intermittent urethral catheters are used by large groups of people for, for example, self-catheterization, a daily life procedure that is performed several times a day. Typically, catheters for intermittent catheterization are used by patients suffering from symptoms of urinary retention, such as, for example, spinal cord injury, multiple sclerosis or prostatic hypertrophy. Using an intermittent catheter, the bladder can be drained through a natural or artificial urinary tract. Many catheters, such as those for intermittent catheterization, are provided with a hydrophilic coating or the like, which provides a smooth and slippery surface when wet and allows for safe and comfortable insertion into the urinary tract.

[0003] Urinary catheters are traditionally sold as disposable, single-use products. Users remove the catheter from the assembly packaging, use it once, and then discard the catheter and packaging. However, single-use catheters make the catheterization procedure relatively expensive, and there is a risk that users may be tempted to reuse the catheter multiple times. This is especially true for users in countries and regions where support programs do not exist. However, reusing a catheter that is not intended for such use may result in the hydrophilic coating degrading from the time of the first use, potentially leading to contamination of the catheter after the first use and increasing the risk of urinary tract infections and other complications.

[0004] On the other hand, reusable urinary catheters are advantageous in reducing user costs and may also be advantageous in reducing the amount of waste generated by the use of disposable catheters. Therefore, from both an economic and environmental standpoint, reusable catheters would be advantageous.

[0005] Several proposals for reusable urethral catheters have been made over the years. For example, U.S. Patent No. 4,754,877 by the same applicant discloses a storage container for cleaning and storing reusable urethral catheters between uses. Furthermore, recently filed International Publications 2020 / 252003, 2020 / 252032, 2020 / 252045, and 2020 / 263,859 disclose different types of storage containers for sterilization or disinfection of used catheters.

[0006] However, various issues still need to be resolved to make reusable urinary catheters comfortable, reliable, and safe to use, so that they become acceptable alternatives for both users and prescribers. In particular, the problems of how to ensure that catheters can be properly disinfected during use and how to prevent excessive degradation of the catheter's hydrophilic coating over time need to be addressed. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Domestic Patent No. 4754877 [Patent Document 2] International Publication No. 2020 / 252003 [Patent Document 3] International Publication No. 2020 / 252032 [Patent Document 4] International Publication No. 2020 / 252045 [Patent Document 5] International Publication No. 2020 / 263859 [Overview of the project]

[0008] Therefore, an object of the present invention is to provide a reusable urethral catheter assembly that at least mitigates the above-mentioned problems.

[0009] This objective is achieved by a reusable urethral catheter assembly, as well as a corresponding method and hydration solution, in accordance with the appended claims.

[0010] According to a first aspect of the present invention, a reusable urethral catheter assembly, A storage container that defines a cavity, A hydrate solution in a cavity, wherein the hydrate solution contains a disinfectant medium and at least one hydrophilic polymer, and the viscosity of the hydrate solution is 40 cP or less, A reusable urethral catheter assembly is provided, comprising a reusable urethral catheter including a shaft, wherein at least a portion of the shaft is provided with a hydrophilic surface, the shaft is enclosed within a cavity in a storage position, and a hydration solution is provided to hydrate and regenerate the hydrophilic surface, disinfect the catheter, and allow the catheter to be repeatedly inserted into and removed from a storage container.

[0011] According to another aspect of the present invention, a hydration solution is provided for the regeneration, disinfection and activation of a reusable hydrophilic urethral catheter, wherein the hydration solution is an aqueous liquid comprising a disinfectant medium and at least one hydrophilic polymer, the concentration of the hydrophilic polymer in the hydration solution being at least 0.25% by weight, and the viscosity of the hydration solution being 40 cP or less.

[0012] According to yet another aspect of the present invention, a method for creating a reusable hydrophilic urethral catheter for repeated use, A hydrate containing a disinfectant medium and at least one hydrophilic polymer, wherein the hydrate has a viscosity of 40 cP or less, is inserted into the cavity of the storage container. A method is provided which includes inserting a catheter into a storage container before or after the insertion of a hydration solution, wherein the hydration solution hydrates and regenerates the hydrophilic surface of the catheter and disinfects the catheter.

[0013] In this context, a disinfectant medium refers to a medium that eliminates many or all pathogenic microorganisms, with some exceptions such as bacterial spores. A disinfectant medium may also be called a disinfectant. However, in some embodiments, a disinfectant medium may destroy or eliminate the life of any form of microorganism, in which case disinfection may also be called sterilization, and the disinfectant medium may be called a sterilizing medium or sterilizing agent.

[0014] Viscosity is preferably measured at normal room temperature, and preferably at 25°C.

[0015] The inventors have found that adding a certain amount of hydrophilic polymer to the hydration solution offers significant advantages, as it regenerates the hydrophilic surface of the catheter. When the catheter is stored in the hydration solution, the hydrophilic polymer in the solution is thought to intertwine and loosely bond to the catheter's hydrophilic surface. This creates a new outermost hydrophilic layer after each use of the catheter during storage in the hydration solution. As a result, the catheter offers lower friction, especially after multiple uses, making it more comfortable for repeated use. The catheter, particularly its hydrophilic surface, is also more durable and can be used more times and for longer periods.

[0016] Reusable catheters can be reused multiple times in a safe, convenient, and comfortable manner. As a result, catheters can be reused for days, weeks, months, or even years.

[0017] In particular, this effect was found to be significant when the concentration of the hydrophilic polymer in the hydration solution was relatively high, and to improve further as the concentration of the hydrophilic polymer increased. How high the concentration of the hydrophilic polymer can be depends to some extent on the hydrophilic polymer used, especially its molecular weight. Hydrophilic polymers with high molecular weight may be used at lower concentrations and still provide very beneficial results, but hydrophilic polymers with lower molecular weight should preferably be used at higher concentrations.

[0018] However, the overall concentration of the hydrophilic polymer in the hydration solution should preferably be at least 0.25% by weight, more preferably at least 0.5% by weight, and most preferably at least 1% by weight.

[0019] However, it has also been found that if the concentration of the hydrophilic polymer is too high, it is harmful. When the concentration of the hydrophilic polymer is high, the viscosity of the hydration liquid becomes too high, increasing the friction on the hydrophilic surface of the catheter. Also, if the viscosity is too high, the hydration liquid adheres to the catheter, becomes dirty, and handling and use become difficult. The hydration liquid, if its viscosity is too high, may also remain in the discharge opening and / or the internal lumen of the catheter, thereby obstructing the flow of urine through the catheter.

[0020] Therefore, the concentration of the hydrophilic polymer in the hydration liquid needs to be balanced such that the positive effect of the regeneration of the hydrophilic surface of the catheter is optimized, while avoiding the drawbacks of a hydration liquid having too high a viscosity. It has been found that the viscosity should be 40 cP or less.

[0021] The hydration liquid is preferably an aqueous liquid. The aqueous liquid preferably contains at least 50% by weight, preferably at least 60% by weight, more preferably at least 70% by weight, and most preferably at least 80% by weight of water.

[0022] Many different hydrophilic polymers can be used in the hydration solution, and all have been found and experimentally verified to yield beneficial results. Preferably, the hydrophilic polymer comprises at least one of polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), polyethylene oxide (PEO), and hydroxypropyl methylcellulose (HPMC). However, other hydrophilic polymers may also be used. In the embodiments, the hydrophilic polymer is preferably at least one of the following: polyvinyl compounds, polylactic acid, particularly polyvinylpyrrolidone, polysaccharides, particularly heparin, dextran, xanthan gum, derivatized polysaccharides, hydroxypropyl cellulose, methylcellulose, polyurethane, polyacrylate, polyhydroxyacrylate, polymethacrylate, polyacrylamide, polyalkylene oxide, particularly polyethylene oxide, polyvinyl alcohol, polyamide, polyacrylic acid, copolymers of the aforementioned polymers, copolymers of vinyl compounds and acrylates or anhydrides, copolymers of vinylpyrrolidone and hydroxyethylmethyl acrylate, and cationic copolymers of polyvinylpyrrolidone, polymethyl vinyl ether, and maleic anhydride. Most preferably, the hydrophilic polymer is polyvinylpyrrolidone.

[0023] In a particularly preferred embodiment, the hydrophilic polymer comprises PVP. In one embodiment, PVP has a molecular weight in the range of 2 to 2000 kg / mol, preferably in the range of 30 to 1800 kg / mol, more preferably in the range of 40 to 1700 kg / mol. PVP may be, for example, PVP K12 having a molecular weight of 4 to 6 kg / mol, PVP K15 having a molecular weight of 6 to 15 kg / mol, PVP K30 having a molecular weight of 40 to 80 kg / mol, PVP K60 having a molecular weight of 390 to 470 kg / mol, PVP K85 having a molecular weight of 900 to 1200 kg / mol, and / or PVP K90 having a molecular weight of 1000 to 1700 kg / mol. In a preferred embodiment, the hydration solution comprises at least one of PVP K12, PVP K15, PVP K30 and PVP K90. In an even more preferred embodiment, the hydration solution comprises at least one of PVP K30 and PVP K90.

[0024] In one embodiment, the hydration solution comprises PVP having a molecular weight in the range of 40 to 80 kg / mol, and the concentration of PVP in the hydration solution is in the range of 5 to 20 wt%, preferably 5 to 17 wt%, more preferably 10 to 16 wt%, most preferably 12 to 15 wt%. Thereby, very good regeneration of the hydrophilic surface is obtained, and at the same time, a viscosity within a good range for handling and use of the catheter is obtained.

[0025] In another embodiment, the hydration solution comprises PVP having a molecular weight in the range of 1000 to 1700 kg / mol, and the concentration of PVP in the hydration solution is in the range of 0.25 to 5.0 wt%, preferably 1.0 to 5.0 wt%, preferably 1.5 to 4.0 wt%, more preferably 2.0 to 3.0 wt%, most preferably 2.2 to 2.8 wt%. Again, very good regeneration of the hydrophilic surface is obtained, and at the same time, the viscosity is within a good range for handling and use of the catheter.

[0026] In general, regardless of which hydrophilic polymer is used, the concentration of the hydrophilic polymer in the hydration solution is preferably at least 1.0% by weight, preferably at least 1.5% by weight, preferably at least 2.0% by weight, and more preferably at least 2.5% by weight. This is especially true for hydrophilic polymers having low or moderately high molecular weights.

[0027] The viscosity of the hydration solution is 40 cP or less. At 40 cP, the hydration solution can still be used for wetting and regenerating hydrophilic surfaces and does not prevent the use of the catheter for its intended purpose. However, some measures may be necessary, such as scraping off excess and residual liquid. For this purpose, it is preferable to have a slightly lower viscosity, such as 30 cP or less, preferably 25 cP or less, more preferably 20 cP or less, and most preferably 15 cP or less. Such a lower viscosity range further improves the handling and efficiency of the catheter for use.

[0028] Since pure water at 20°C has a viscosity of approximately 1 cP, when a hydrophilic polymer is added to the hydration solution, the viscosity of this liquid will exceed 1 cP. Preferably, the viscosity of the hydration solution is in the range of 2 to 40 cP, preferably 5 to 30 cP, more preferably 7 to 20 cP, more preferably 10 to 15 cP, and most preferably 11 to 13 cP.

[0029] By using different types of disinfection media, bacteria remaining on the catheter after use can be killed, providing a disinfected, and possibly sterile, catheter for subsequent use. In a preferred embodiment, the disinfection media includes a chemical disinfectant.

[0030] In embodiments, the chemical disinfectant may include at least one of benzalkonium chloride (BAC), sodium hypochlorite, silver nitrate, povidone-iodine (PVP-iodine), and triclosan. However, other chemical disinfectants may also be used. In preferred embodiments, the disinfectant medium includes BAC.

[0031] However, other disinfectants, such as nanoparticles with bactericidal effects, can also be used as disinfectant media. Examples of these include, but are not limited to, silver, zinc oxide, and copper oxide.

[0032] In addition to the disinfectant medium, further disinfection may be performed when the catheter is located in the storage container, for example, by irradiation with UV radiation or visible light, heating, electric current, or other forms of energy, in order to provide even more efficient disinfection.

[0033] The hydration solution may further contain a surfactant. It has been found that using a surfactant in the hydration solution makes the regeneration process faster and more efficient. The total concentration of the surfactant is preferably in the range of 0.01 to 0.5% by weight. The surfactant may be a nonionic surfactant.

[0034] In this application, "surfactant" means all molecules that have surface-active properties and can reduce surface tension or improve wetting of a substrate by a liquid.

[0035] Surfactants are preferably organic compounds and are amphiphilic, meaning they contain both hydrophobic groups (their tails), usually long alkyl chains, bonded to hydrophilic or water-soluble enhancing functional groups (their heads). Thus, surfactants contain both water-insoluble (or oil-soluble) and water-soluble components. Surfactants diffuse into water and, when water is mixed with oil, adsorb to the interface between air and water or between oil and water.

[0036] The surfactant is preferably water-soluble.

[0037] Furthermore, the surfactant is preferably nonionic. This limits interaction with human tissue, and the surfactant does not interact with, for example, ionic substances, pH buffers, and other optional additives. However, other surfactants such as zwitterionic, anionic, or cationic surfactants may also be used. In addition, the surfactant is preferably relatively large in chain / molecule, which further reduces potential interaction with human tissue.

[0038] Examples of ionic surfactants that may be used in wetting solutions and / or hydrophilic coatings / surfaces include alkyl sulfates (such as sodium dodecyl sulfate), sodium cholate, sodium bis(2-ethylhexyl) sulfosuccinate, quaternary ammonium compounds such as cetyltrimethylammonium bromide or chloride, lauryldimethylamine oxide, sodium N-lauroyl sarcosinate, and sodium deoxycholate.

[0039] Examples of nonionic surfactants that may be used in wetting solutions and / or hydrophilic coatings / surfaces include one or more alkyl polyglucosides, branched secondary alcohol ethoxylates, ethylene oxide / propylene oxide copolymers, nonylphenol ethoxylates, octylphenol ethoxylates, and specialty alkoxylates such as Tween 80 and Tween 20.

[0040] Other examples of surfactants that can be used in wetting solutions and / or hydrophilic coatings / surfaces include, but are not limited to, saponified coconut oil, vitamin E, polyoxyethylene sorbitan, monolaurate, sodium dodecyl sulfate, polysorbate, La-phosphatidylcholine, lecithin, stearyl stearate, sodium stearate, sodium laurate, sodium myristate, sodium palmitate, sodium oleate, polyethylene glycol monododecyl ether, glycolate ethoxylate lauryl ether, glycolate ethoxylate oleyl ether, ethylene glycol monododecyl ether, polyoxyethylene Examples include lycerol esters, polyglyceryl esters, diglyceryl diisostearate, diglyceryl monolaurate, diglyceryl monooleate, sodium doxate, sodium dioctyl sulfosuccinate, sodium dioctyl sulfosuccinate, sodium dodecylbenzenesulfonate, perfluorobutanesulfonic acid, 3-sulfopropyl ethoxylate laurylphenyl ether, sodium laurate, sodium N-acyl sarcosinate, and sodium N-lauroyl sarcosinate, as well as one or more different types of cellulose derivatives such as hydroxypropyl cellulose and hydroxypropyl methylcellulose.

[0041] In preferred embodiments, the surfactant is one or more of the following: Tween 80, Brij 35, all commercially available from Sigma Aldrich; TEGO Betain F50, commercially available from Evonik Industries; Kolliphor P188, Kolliphor P407, both commercially available from BASF; and HPMC 4M, commercially available from DuPont / Dow Chemicals.

[0042] The hydration solution may further contain a pH buffer to ensure that the pH of the liquid is maintained within a preferred range, for example, between 4 and 8. The pH buffer may be citric acid, but other buffers such as acetic acid, phosphate buffers, carboxylic acids, amino acids, aminosulfonic acids, and inorganic acids may be used.

[0043] The hydration solution may further contain other additives, such as osmotic pressure increasing agents, for example, sodium chloride.

[0044] The hydrophilic surface of the catheter preferably contains polyvinylpyrrolidone (PVP).

[0045] The hydrophilic surface may be provided as a hydrophilic coating placed on the substrate of the urethral catheter, as is well known in the art. However, the hydrophilic surface may alternatively be provided as an integrated part of the urethral catheter, such as an integrated layer, or the entire shaft of the urethral catheter may be made of a hydrophilic material. The hydrophilic coating / surface is preferably provided so as to offer low friction when wet.

[0046] The hydrophilic coating / surface may be a surface provided with a hydrophilic coating, for example, manufactured in accordance with European Patent No. 0 / 093 / 093 and European Patent No. 0 / 217 / 771, the literature of which is incorporated herein by reference in whole.

[0047] PVP is a preferred hydrophilic material for hydrophilic surfaces, but other hydrophilic materials may be used, such as hydrophilic polymers selected from polyvinyl compounds, polysaccharides, polyurethanes, polyacrylates, or copolymers of vinyl compounds with acrylates or anhydrides, particularly polyethylene oxide, heparin, dextran, xanthan gum, polyvinyl alcohol, hydroxypropyl cellulose, hydroxypropyl methylcellulose, methylcellulose, copolymers of vinylpyrrolidone with hydroxyethyl methyl acrylate, or copolymers of polymethyl vinyl ether with maleic anhydride. Furthermore, the term hydrophilic coating / surface should be understood in a broad sense, and in embodiments, the hydrophilic coating / surface may include the entire insertable portion of a urethral catheter formed of the hydrophilic material.

[0048] In a preferred embodiment, the urethral catheter is a urethral catheter for intermittent and short-term use. The term “short-term use” refers to use that is time-limited, particularly use limited to a period of less than 15 minutes, preferably less than 10 minutes, and most preferably less than 5 minutes.

[0049] In this application, the term “proximal” is used to refer to the end or portion of the catheter that is inserted into the user’s body, i.e., the end or portion of the catheter that is in close proximity to the user’s body during use and / or that first enters the user’s body at insertion. The term “distal” is used to refer to the end or portion of the catheter that is opposite the proximal end or portion and is typically further away from the user’s body. For consistency, when the terms “distal” and “proximal” are used in the context of other components not intended to be introduced into the user’s body, “proximal” refers to the end or portion of the catheter that is closer to the proximal end, and “distal” refers to the end or portion that is located opposite such proximal end or portion.

[0050] A urethral catheter assembly comprises a storage container, such as a package or case, for containing a hydrate solution, and at least an insertable portion of the urethral catheter for storage, particularly between uses. In one embodiment, the storage container completely encloses the urethral catheter. In such embodiments, the storage container may be provided with a resealable closure, such as a cap. However, it is also possible to position all or part of the non-insertable portion outside the storage container. In such embodiments, the exposed portion of the urethral catheter that is outside the storage container may form a closure of the storage container.

[0051] The urethral catheter may be placed already immersed in the hydrate solution from the start, i.e., before the first use. However, the hydrate solution may be left separate from the catheter before the first use. For example, the hydrate solution may be placed in a separate compartment or container of the assembly and released after the first use into the storage container in which the catheter was originally placed. In another embodiment, the urethral catheter assembly comprises an additional container for housing the catheter before the first use and a storage container that can hold the hydrate solution and house the catheter after the first use. The hydrate solution may also be provided in a separate container, such as a bottle, so as to adequately fill the storage container during long-term use, and possibly refill it.

[0052] The storage container is preferably impermeable to the wetting solution and preferably made from a liquid-impermeable material. This ensures that the liquid does not penetrate the storage container during storage, improving the shelf life of the product. However, in embodiments where the hydration solution is kept separate from the catheter, for example, the material does not need to be completely liquid-impermeable.

[0053] The urethral catheter assembly may be provided to the user in a disposable outer package. This disposable outer package may contain a urethral catheter, storage container, and hydrate solution in various configurations. For example, both the urethral catheter and hydrate solution may be placed in the storage container already contained within the outer package. However, the outer package may surround one or both of the urethral catheter and hydrate solution, separated from the storage container. For example, the urethral catheter may be placed loosely or in a separate package outside the storage container within the outer package. The outer package may also contain two or more urethral catheters, so that the first catheter can be discarded after its service life and replaced with the next. For example, the outer package may contain two, five, ten, or more catheters. Additionally or alternatively, the hydrate solution may be provided in a separate container, such as a bottle, to wet the catheter or to pour into the storage container after or immediately before the first use.

[0054] Reusable catheters may be used multiple times and then discarded for new catheters or new urethral catheter assemblies to be used in the same storage container.

[0055] A urethral catheter may have a connector located at an inaccessible distal end, such as a flared connector, a funnel-shaped end, or a flared end. Preferably, the catheter has an internal lumen extending from one or more drainage openings, so-called eyes or eyelets, located at or near the proximal insertion end, to an outlet located at or near the distal end. The drainage openings may be located at the proximal tip of the elongated shaft, i.e., forming a centrally located opening in the longitudinal extension of the internal lumen. Additionally or alternatively, one or more drainage openings may be formed in the sidewall of the elongated shaft and exit in a radially outward direction. In one embodiment, the elongated shaft has a rounded, closed proximal end and one or more drainage openings located in the sidewall of the elongated shaft.

[0056] A portion or all of the catheter shaft may form the insertable portion or insertable length of the catheter. At least the insertable portion may be provided with a hydrophilic coating / surface, or otherwise a hydrophilic coating / surface that exhibits reduced friction when wet may be provided. Furthermore, the distal portion may have a larger cross-sectional dimension than the catheter shaft in at least a portion thereof. The distal portion may be, for example, flared or funnel-shaped, with increasing dimensions toward the distal end, thereby enabling connection of tubes, urine collection bags, etc.

[0057] These and other aspects of the present invention will become apparent and clarified by reference to the embodiments described below.

[0058] For illustrative purposes, the present invention will be described in more detail below with reference to embodiments shown in the accompanying drawings. [Brief explanation of the drawing]

[0059] [Figure 1] This is a cross-sectional view of a reusable urethral catheter assembly according to an embodiment of the present invention. [Modes for carrying out the invention]

[0060] In the following detailed description, preferred embodiments of the present invention are interchangeable between embodiments and may be combined in different ways unless otherwise specified. For clarity, it should also be noted that the dimensions of certain components shown in the drawings may differ from the corresponding dimensions in actual embodiments of the present invention, such as the length of a medical device. Furthermore, although the following detailed description relates to a urethral catheter assembly, it should be understood that the same principles may be applied to assemblies for other hydrophilic catheters, as well as assemblies for other hydrophilic medical devices.

[0061] A urethral catheter assembly 1, as shown in Figure 1, comprises a catheter 2 having an insertable portion 21 on the catheter shaft, which includes an insertable proximal portion with an insertion tip, and an ininsertable portion 22 which is a distal portion forming a connector. Preferably, the ininsertable portion 22 is larger in diameter than the insertable portion 21 in at least a portion of it. The rear end of the ininsertable portion may be flared or funnel-shaped and may be arranged to connect to a tapered connector such as a urine collection bag. However, the ininsertable portion may alternatively have a relatively uniform cross-sectional area.

[0062] At least a portion of the insertable portion 21 forms an elongated shaft of an insertable length that is inserted into the user's natural or artificial body opening, such as the user's urethra.

[0063] The insertable portion includes an insertable tip, which may be a closed, rounded end. Furthermore, the insertable portion may include one or more discharge openings 23 located near the insertable tip, which are so-called catheter eyes or eyelets, leading to a lumen extending through the catheter and to a discharge outlet located at the posterior end of the non-insertable portion 22.

[0064] The insertable portion may be 80-140mm for female users and 200-350mm for male users.

[0065] The insertable portion 21 may include a hydrophilic coating / surface, as is well known in the art, to form a hydrophilic catheter. The hydrophilic coating / surface may be in the form of a hydrophilic coating, such as PVP, which provides a low-friction surface when wetted with a wetting solution. Although PVP is a preferred hydrophilic material, other hydrophilic materials may be used, as illustrated above.

[0066] Catheters are intended for repeated use, and should be stored in a storage container so that at least the insertion portion of the catheter is in contact with the hydration solution during its lifespan. The hydration solution activates and regenerates the hydrophilic surface of the catheter and also helps disinfect the catheter for subsequent use.

[0067] In the storage position, the catheter is housed within the storage container 3, forming a closed cavity in which at least the insertable portion of the catheter is positioned. In an exemplary example, the entire catheter is placed within the storage container. The cavity is preferably impermeable to the hydration solution. The storage container is preferably made of a relatively rigid material, at least in part. However, the storage container may also be made of a flexible material such as foil. The storage container may be transparent, but alternatively, it may be opaque or semi-opaque. The storage container may take the form of a tube or hose, a bottle, a case, etc. The storage container is preferably positioned to enclose the catheter relatively narrowly.

[0068] Storage containers can be made from materials such as PVC plastic 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 contain fibers, such as fibrous materials. Furthermore, many other types of materials can also be used, especially for embodiments where the storage container is to be reused many times, and for many catheters. In such embodiments, in particular, the storage container can be made from materials such as metal, glass, and ceramic, which are easier to clean and wash, more durable, and in some cases more rigid.

[0069] The storage container may be arranged to receive the catheter in a relatively linear configuration. However, alternatively, the storage container may be configured to accommodate the catheter in a curved or bent configuration to provide a more compact storage container.

[0070] The storage container may preferably include an opening located above or above the non-insertable portion 22 of the catheter. The opening may be provided with a closure 31, such as a cap or lid. The closure may be connected to the opening by threads, a friction fit, or the like. Thus, the closure can be removed to open the opening in order to pull out the catheter for use, then closed again when the catheter is used, and then reinserted into the storage container.

[0071] The closure portion can be made of a relatively rigid material, such as a polymer material, and preferably closes the opening to prevent the hydration solution from leaking out when the catheter is stored in a storage container.

[0072] During use, the storage container is at least partially filled with the hydrated solution 4 described above, which is arranged to immerse at least a portion, preferably at least all, of the insertable portion when the catheter is placed in the storage container.

[0073] To allow for repeated use of the catheter, it can be repeatedly inserted into and removed from the storage container.

[0074] As described above, the hydration solution comprises water to moisten and activate the hydrophilic surface of the catheter, a hydrophilic polymer configured to regenerate the hydrophilic surface of the catheter during its service life, and a disinfectant medium to disinfect, and possibly sterilize, the catheter before its next use.

[0075] In some embodiments, the hydration solution may also contain other additives such as surfactants, osmotic pressure enhancers, and pH buffers.

[0076] Experimental results The following discusses several experimental tests.

[0077] In the initial experimental line, the viscosity of the hydrate solution at 25°C was evaluated. Hydration solutions containing various concentrations of hydrophilic polymer were used. The hydrophilic polymer used in these tests was PVP K30 with a molecular weight of 40–80 kg / mol. The hydrophilic polymer was mixed with water using a magnetic stirrer. The viscosity of the liquid was measured with a viscometer. The hydrate solution was then used as a storage solution for hydrophilic urethral catheters. The hydrate solution was placed in a storage container along with the urethral catheter. The urethral catheter was then removed from the hydrate solution, and the friction and feel of the catheter surface were manually evaluated. Conventional friction measurements were found to be unusable due to the liquid remaining on the surface yielding erroneous results. Instead, the friction and feel of the catheter were manually evaluated by experienced testers. The feel of the catheter surface was evaluated immediately after removal from the storage container and after scraping off excess liquid from the surface. Table 1 shows the viscosity, concentration, and manual evaluation of different PVP solutions.

[0078] Table 1. Viscosity of PVP K30 solutions with various polymer concentrations. [Table 1]

[0079] Thus, it was found that as the concentration of the hydrophilic polymer increases, the viscosity increases exponentially and rapidly. Approximately, the viscosity doubles for every 5% increase in the PVP K30 concentration.

[0080] From the evaluation, it can be concluded that hydration solutions with a viscosity of up to 40 cP are acceptable, but even better results can be achieved when the viscosity is 30 cP or less, preferably 25 cP or less, more preferably 20 cP or less, and most preferably 15 cP or less. It can be concluded that the viscosity of the hydration solution should preferably be in the range of 2 to 40 cP, preferably 5 to 30 cP, more preferably 7 to 20 cP, more preferably 10 to 15 cP, and most preferably 11 to 13 cP.

[0081] In a separate series of tests, different hydrophilic polymers were tested to evaluate their suitability for use with hydration solutions to regenerate the hydrophilic surface of urethral catheters after use. Catheters were stored in different hydration solutions between uses and tested multiple times a day. Tests were performed manually to simulate the abrasion that occurs during actual urethral insertion, and the feel and slipperiness of the catheters were evaluated. As a baseline, the manually evaluated feel of a commercially available LoFric® catheter was used. Catheters were graded from 9-1 each time, where 9 is equivalent to the feel of the baseline catheter. Grades 9-7 were very good, 6-4 were acceptable, and grade 3-1 was poor and considered unsuitable for use as a urethral catheter. These measurement results are shown in Table 2 below.

[0082] Table 2. Manual evaluation of friction during repeated use. [Table 2]

[0083] The concentrations of all additives were selected to provide a viscosity within a preferred range of 11.5–12 cP. Hydration solutions containing hydrophilic polymers were found to provide long-term durability for the catheter, thereby making them more suitable for use in reusable catheters compared to hydration solutions containing, for example, glycerin or those without additives.

[0084] From this, it can be concluded that all examples immersed in a hydration solution containing a hydrophilic polymer between uses were significantly better for repeated use than those immersed in pure water or water containing other additives such as glycerin. The hydrophilic polymer in the hydration solution is thought to regenerate the hydrophilic surface of the catheter after each use, thereby making it better for subsequent use. Regeneration appears to be particularly good for PVA and PEO, as well as when different types of PVP are used.

[0085] In a separate experimental line, hydration solutions with different concentrations of several hydrophilic polymers were evaluated. Again, catheters were stored in different hydration solutions between uses and tested multiple times a day. The feel and slipperiness of the catheters were evaluated manually, simulating the abrasion that occurs during actual urethral insertion. The manually evaluated feel of a commercially available LoFric® catheter was used as a baseline. Each catheter was graded from 9-1, where 9 is equivalent to the feel of the baseline catheter. Grades 9-7 were considered very good, 6-4 acceptable, and 3-1 poor and unsuitable for use as a urethral catheter. These measurement results are shown in Table 3 below.

[0086] Table 3. Manual evaluation of friction during repeated use. [Table 3]

[0087] From this, it can be concluded that all examples immersed in a hydration solution containing a hydrophilic polymer between uses were significantly better for repeated use than those immersed in pure water or water containing other additives such as glycerin. It was found that higher concentrations of the hydrophilic polymer in the hydration solution improved regeneration and increased the likelihood of repeated use. Therefore, it is considered necessary to find a balance between the highest possible concentrations of the hydrophilic polymer in order to improve regeneration and to keep the concentration of the hydrophilic polymer sufficiently low to avoid excessive viscosity.

[0088] It was further found that mixtures of PVPs with different molecular weights may be beneficial.

[0089] Furthermore, it was found that adding a small amount of surfactant could further improve the regenerative properties of the hydration solution.

[0090] In a separate experimental line, hydrates containing different types of disinfectants were used and their disinfectant effects were evaluated. The hydrates contained 5% by weight of PVP K30 and various disinfectants. For comparative examples, a hydrate containing PVP K30 but no disinfectant, and a hydrate consisting only of water were used.

[0091] For the test, the catheter was first activated in a hydrate containing a disinfectant. Then, the catheter was immersed in an E. coli suspension. Next, the catheter was rinsed with pure water and then immersed again in the same hydrate used for activation for 4 hours. Afterward, the catheter was transferred to a growth medium and incubated at 37°C for 19.5 hours. The presence or absence of bacterial growth during incubation was then determined. These measurement results are shown in Table 4 below.

[0092] Table 4. Manual evaluation of friction during repeated use. [Table 4]

[0093] These measurements showed that all disinfectants tested reduced bacterial growth, thereby being effective in sterilizing catheters within a limited time. The control experiment showed that bacterial growth occurred when no disinfectant was used.

[0094] (Note) Herein, specific embodiments of the present invention have been described. However, as will be apparent to those skilled in the art, several alternatives are possible. For example, many other hydrophilic polymers other than those described above, as well as other disinfectants, may be used. Furthermore, other additives such as surfactants may be used in various concentrations. Such other additives may be beneficial in certain situations but not necessary in others.

[0095] Such and other obvious modifications should be considered within the scope of the invention as defined by the appended claims. It should be noted that the embodiments described above are illustrative, not limiting, of the invention, and that those skilled in the art can design many alternative embodiments without departing from the appended claims. In the claims, reference numerals placed between parentheses should not be construed as limiting the claims. The words “including” and “equipped” do not preclude the existence of other elements or steps other than those enumerated in the claims. The words “a” or “a” preceding an element do not preclude the existence of multiple such elements. Furthermore, a single unit may perform the functions of some of the means described in the claims.

Claims

1. A reusable urethral catheter assembly, A storage container that defines a cavity, A hydrated solution in the cavity, wherein the hydrated solution comprises a disinfectant medium and at least one hydrophilic polymer, and the viscosity of the hydrated solution is 40 cP or less. A reusable urethral catheter comprising a shaft, wherein at least a portion of the shaft is provided with a hydrophilic surface, the shaft is enclosed within a cavity in a storage position, the hydration solution hydrates and regenerates the hydrophilic surface, disinfects the urethral catheter, and the urethral catheter is configured to be repeatedly inserted into and removed from the storage container, A reusable urethral catheter assembly wherein the hydrophilic polymer comprises polyvinylpyrrolidone (PVP), and the concentration of PVP in the hydrate is 10 to 16% by weight.

2. The reusable urethral catheter assembly according to claim 1, wherein the hydrophilic polymer comprises at least one of polyvinyl alcohol (PVA), polyethylene oxide (PEO), and hydroxypropyl methylcellulose (HPMC).

3. The reusable urethral catheter assembly according to claim 1 or 2, wherein the PVP has a molecular weight in the range of 2 to 2000 kg / mol.

4. A reusable urethral catheter assembly according to any one of claims 1 to 3, wherein the PVP has a molecular weight in the range of 40 to 80 kg / mol.

5. A reusable urethral catheter assembly according to any one of claims 1 to 4, wherein the PVP has a molecular weight in the range of 1000 to 1700 kg / mol.

6. The reusable urethral catheter assembly according to any one of claims 1 to 5, wherein the concentration of the hydrophilic polymer in the hydrate is at least 0.25% by weight.

7. The reusable urethral catheter assembly according to any one of claims 1 to 6, wherein the viscosity of the hydrated solution is 30 cP or less.

8. The reusable urethral catheter assembly according to any one of claims 1 to 7, wherein the viscosity of the hydrate is in the range of 2 to 40 cP.

9. The reusable urethral catheter assembly according to any one of claims 1 to 8, wherein the disinfectant medium comprises a chemical disinfectant.

10. The reusable urethral catheter assembly according to claim 9, wherein the chemical disinfectant comprises at least one of benzalkonium chloride (BAC), sodium hypochlorite, silver nitrate, povidone-iodine (PVP-iodine), and triclosan.

11. The reusable urethral catheter assembly according to any one of claims 1 to 10, wherein the disinfectant medium comprises BAC.

12. The reusable urethral catheter assembly according to any one of claims 1 to 11, wherein the hydrate further comprises a surfactant.

13. The reusable urethral catheter assembly according to claim 12, wherein the total concentration of the surfactant is in the range of 0.01 to 0.5% by weight.

14. The medical device assembly according to claim 12 or 13, wherein the surfactant is a nonionic surfactant.

15. A method for creating a reusable hydrophilic urethral catheter for repeated use, A hydrate containing a disinfectant medium and at least one hydrophilic polymer, The hydrated solution with a viscosity of 40 cP or less is inserted into the cavity of the storage container, The procedure includes inserting the urethral catheter into the storage container before or after inserting the hydration solution, wherein the hydration solution hydrates and regenerates the hydrophilic surface of the urethral catheter and disinfects the urethral catheter, The hydrophilic polymer comprises PVP, and the concentration of PVP in the hydrate solution is 10 to 16% by weight.

16. A hydration solution for the regeneration, disinfection, and activation of a reusable hydrophilic urethral catheter, wherein the hydration solution is an aqueous liquid comprising a disinfectant medium and at least one hydrophilic polymer. The concentration of the hydrophilic polymer in the hydrate solution is at least 0.25% by weight, and the viscosity of the hydrate solution is 40 cP or less. The hydrophilic polymer is a hydrated solution containing PVP, wherein the concentration of PVP in the hydrated solution is 10 to 16% by weight.

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