Abstract:
A method of making a ready-to-use catheter assembly is provided, which can be immediately used by a patient. The ready-to-use catheter assembly ensures that the catheter does not suffer from a loss of quality during its shelf life and a wetting medium are provided. The method comprises: placing a catheter with an inactivated hydrophilic outer surface at least along its insertable length and a wetting medium in a catheter package; treating the catheter package with the catheter and the wetting medium with electro-magnetic and/or particle radiation while at least initially the hydrophilic outer surface at least along the insertable length of the catheter remains inactivated; and activating the hydrophilic outer surface at least along the insertable length of the catheter with the wetting medium during and/or after the radiation treatment and wherein the wetting medium decreases in viscosity when submitted to electro-magnetic and/or particle radiation.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to foreign European patent application No. EP 16001196.1, filed on May 25, 2016, the disclosure of which is incorporated by reference in its entirety. 
       FIELD OF THE INVENTION 
       [0002]    The present patent application refers to a method of making a ready-to-use catheter assembly, a catheter assembly for use in the method, a ready-to-use catheter assembly and the use of a wetting medium in the method. 
       BACKGROUND 
       [0003]    Such ready-to-use catheter assemblies are usually used for intermittent catheterization by patients who are unable to empty their bladder naturally. The bladder is then emptied in regular intervals by the patients themselves using a urinary catheter. Urinary catheters are usually provided with a surface treatment using a lubricant to reduce friction in order to allow for an easier and less traumatic insertion into the urethra. Currently, there are two major categories of catheters having lubricated surfaces, namely, gel-coated catheters and hydrophilic coated catheters. 
         [0004]    Gel-coated catheters are made easier to insert by application of a water-based gel to the catheter surface. Typically, this gel is supplied with the packaged catheters and a system is provided with the packaged catheters to apply the gel to the surface of the catheters. The gel can either be put onto the catheter surface just before or during the packaging operation or the gel is applied to the surface of the catheter as the catheter is inserted by the patient. 
         [0005]    In a hydrophilic coated catheter, the catheter is provided with a hydrophilic coating which is adhered to the outer surface of the catheter. Before insertion of the catheter, the hydrophilic coating is activated by swelling in contact with a hydrating liquid such as water. The catheter surface then has an extremely low coefficient of friction. There exist different systems for hydrophilic coated catheters. It is known that a sterile, individually packed single use catheter is provided in a dry state or condition. The patient opens the package, pours water into the package, waits for approximately thirty seconds and then removes the catheter from the package, which is now ready for insertion. In another version of the hydrophilic coated catheter, the catheter is provided in a package that already contains enough loose liquid water to cause the catheter to be immersed. The user then simply opens the package and removes the catheter which is ready for insertion without the need to add water or to wait. Other products provide the amount of liquid necessary for the immersion of the catheter in a separate compartment of the package or in a sachet arranged in the package. With these products, the user must open a separate compartment of the package or the sachet allowing the liquid to enter the catheter containing chamber for activating the hydrophilic coated surface. 
         [0006]    In order to reduce the risk of infections in the urinary tract due to intermittent catheterization, the urinary catheters as well as the wetting media used need to be sterilized. The sterilization of medical devices is usually performed at the time of manufacture using techniques which are well known in the art as for example radiation such as beta radiation or gamma radiation. However, sterilization of a catheter such as an intermittent urinary catheter with a hydrophilic coating is generally regarded as cumbersome if not impossible using conventional techniques. Radiation sterilization of a catheter with a hydrophilic coating has the well known problem that an undesirable chemical modification of said coating occurs, decreasing the quality of the coating which may lead to an increase of the coefficient of friction. 
         [0007]    It is therefore known to add one or more buffers, anti-oxidants, or other additives to the wetting fluids to prevent ruining the coating of the catheter during radiation sterilization. Furthermore, it is also known to add hydrophilic polymers to the wetting solution, wetting the hydrophilic coating of the catheter with this polymer solution and to then sterilize the wet or activated hydrophilic coated catheter using radiation. 
         [0008]    A further method of preparing a ready-to-use urinary catheter and a catheter assembly for use are disclosed in WO 2014/063711 A1. In this method, a catheter assembly is provided which comprises a first compartment in which a catheter with a hydrophilic coating is placed and a second compartment which comprises the liquid swelling medium. The catheter assembly is then sterilized and after sterilization, the liquid swelling medium is added to the first compartment for wetting and activating the catheters&#39; exterior coating. After that, the second compartment is removed from the catheter assembly. 
       SUMMARY OF THE INVENTION 
       [0009]    It is an object of the present patent application to provide alternative solutions for making a ready-to-use urinary catheter and a ready-to-use catheter assembly in which the catheter can be stored for its maximum shelf life without suffering any losses to quality, especially to its hydrophilic coating so that the catheter can be safely inserted into the urethra of the patient without causing discomfort. Furthermore, the method and the catheter assembly itself should be simple and cost effective. 
         [0010]    These objects are achieved by a method of making a ready-to-use catheter assembly comprising the following steps: 
         [0011]    Placing a catheter with an inactivated hydrophilic outer surface at least along its insertable length and a wetting medium in a catheter package; 
         [0012]    Treating the catheter package with the catheter and the wetting medium with electro-magnetic or particle radiation while at least initially the hydrophilic outer surface at least along the insertable length of the catheter remains substantially inactivated; 
         [0013]    Activating the hydrophilic outer surface at least along the insertable length of the catheter with the wetting medium during and/or after the radiation treatment; wherein the wetting medium decreases in viscosity when submitted to electro-magnetic and/or particle radiation. 
         [0014]    The outer surface of the catheter is the surface of the catheter which potentially comes into contact with human tissue when being inserted into the urethra of a patient. In order to reduce the friction between the catheter and the urethra, this outer surface is hydrophilic at least along its insertable length and therefore very slippery when activated by a wetting medium. In order to obtain the hydrophilic outer surface, the catheter can be coated with a hydrophilic coating or the entire catheter shaft can be made of a hydrophilic material. 
         [0015]    The term “insertable length” means the length of the catheter shaft which comes into contact with the human tissue when the catheter is inserted into the urethra of a patient. Due to the many different anatomical structures, it is not possible to define an exact length of the insertable length. Typically, the insertable length of catheters used by male patients lies in a range from approximately 30-40 cm and for female users in a range of approximately 10-20 cm. 
         [0016]    The catheter package can be made of a material with low moisture transmission. This means that the package is made of a material that keeps at least an amount of wetting medium inside the catheter package that is large enough to keep the hydrophilic outer surface of the catheter in the activated state for the shelf life of the catheter assembly. Typically, the shelf life of a catheter assembly lies in a range from thirty six months to five years. Examples for a material with low moisture transmission which can be used for the catheter package are composite or multi-laminated materials consisting of aluminum foil, LDPE, MDPE, HDPE, LLDPE or blends of the afore, PP, polyester based polymers (PET), of siloxane coatings. However, it is also possible to provide other methods for keeping the hydrophilic outer surface at least along the insertable length of the catheter in the activated state for the shelf life of the catheter assembly. 
         [0017]    Before the treatment with electro-magnetic and/or particle radiation (the radiation treatment), the wetting medium has a high viscosity. Due to the high viscosity, the wetting medium stays in the catheter package at the place where it has been inserted and does not tend to flow towards the catheter. Therefore, the risk for an accidental wetting of the outer surface of the catheter and therefore the risk of activating the hydrophilic material before the radiation treatment is very low. When the catheter assembly with the catheter and the wetting medium is submitted to energy during the radiation treatment the viscosity of the wetting medium decreases. The wetting medium thus comes in a low viscosity state and can easily be brought into contact with the hydrophilic outer surface of the catheter. This can be done by tilting or turning the catheter package around a specific angle, as for example an angle of approximately 90° or 180°. The wetting medium can be any liquid which reduces its viscosity when external conditions are changed. Examples for such liquids are viscoelastic fluids, Bingham fluids, pseudoplastic fluids, dilatant fluids or Newtonian fluids. Furthermore, the wetting medium can be a gel. It is also possible to use a wetting medium which is initially a solid and changes its state of matter during the radiation treatment from the solid state to the liquid state. 
         [0018]    In a preferred variant of the method, the electromagnetic and/or particle radiation treatment is a sterilizing step for sterilizing the catheter assembly with the catheter and the wetting medium placed in the catheter package. In this case, no additional production step is necessary. 
         [0019]    Preferably, the viscosity of the wetting medium decreases by at least 80%, more preferably at least 90%, when submitted to electro-magnetic and/or particle radiation. In this way, it can be ensured that the wetting medium has a sufficiently low viscosity after the radiation treatment so that an easy activation of the hydrophilic outer surface of the catheter is possible. 
         [0020]    In a variant of the method, the wetting medium is a gel comprising at least one polymer. In this context, the term “gel” refers to gels, hydrogels, high viscous aqueous solutions which contain a polymer or a thixotropic agent. Tests have shown that such gels degrade when submitted to radiation sterilization and transform into the desired aqueous fluid solution. This aqueous fluid solution allows easy activation of the hydrophilic outer surface of the catheter. 
         [0021]    Preferably, the gel has a viscosity of at least 7000 cP, preferably at least 25000 cP, before the radiation treatment. In this case, the viscosity of the wetting medium before the radiation treatment is high enough to enable an easy separation between the wetting medium and the hydrophilic outer surface at least along the insertable length of the catheter. During the radiation treatment, the wetting medium degrades sufficiently, so that it can be easily brought into contact with the hydrophilic outer surface at least along the insertable length of the catheter for activating this surface due to its fluid nature. 
         [0022]    In a further embodiment, the polymer is organic or synthetic carbohydrate or a liquid based polymer. Such a gel combines the desired high viscosity before the radiation treatment and the requested liquid properties for activating the hydrophilic outer surface at least along the insertable length of the catheter after being submitted to electro-magnetic and/or particle radiation. 
         [0023]    In a further variant of the method, the radiation used for the radiation treatment is gamma radiation, x-ray, e-beam or UV. This leads to a sterile state of the whole catheter assembly and also ensures that sufficient energy is delivered to the wetting medium so that the wetting medium transforms into the aqueous solution during the radiation treatment. 
         [0024]    Tests have shown that the best results can be achieved when the energy dose of the radiation is in a range of 1 to 50 kGy, preferably 15 to 45 kGy, more preferably 25 to 45 kGy. With such an energy dose, no damage to the catheter is incurred and the wetting medium degrades and turns into the aqueous liquid. 
         [0025]    In still another variant, the catheter package used in the method can comprise an open channel diversion for separating the catheter with the hydrophilic outer surface at least along its insertable length and the wetting medium from each other before and during the radiation treatment. For example, the catheter package can be provided with at least one welding seam which forms a back taper in the package and in which the wetting medium is arranged. In a variant, the catheter with the hydrophilic outer surface at least along its insertable length and the wetting medium can be separated by a physical barrier. The open channel diversion and the physical barrier ensure that the hydrophilic outer surface at least along the insertable length of the catheter and the wetting medium do not come into contact before and during the radiation treatment which could lead to a degradation of the hydrophilic outer surface. 
         [0026]    It can be further provided that the catheter is surrounded by a sleeve. Due to this sleeve, the patient can easily grip and insert the activated slippery catheter. 
         [0027]    In a further variant of the method, it can be provided that the wetting medium is partially a gel and partially an aqueous solution. The gel forms a plug which holds the aqueous solution in a cavity so that it does not come into contact with the hydrophilic outer surface of the catheter before and during the radiation treatment. During the radiation treatment, the gel experiences a decrease in viscosity so that the activation of the hydrophilic outer surface at least along its insertable length of the catheter can be easily performed after the radiation treatment. In this case, a viscosity decrease of just 10% would be sufficient, because the plug only needs to dislocate to let the aqueous solution pass. 
         [0028]    It is a further object of the present invention to provide a catheter assembly for use in a method as described above. The catheter assembly comprises a catheter package, a catheter with an inactived hydrophilic outer surface at least along its insertable length arranged in the catheter package, and a wetting medium arranged in the catheter package, whereby the wetting medium decreases in viscosity when submitted to electro-magnetic and/or particle radiation. The catheter assembly therefore allows an easy and secure separation between at least the insertable length of the hydrophilic outer surface of the catheter and the wetting medium before and at least initially during the treatment with electro-magnetic and/or particle radiation, and an easy activation of the hydrophilic outer surface of the catheter during and/or after the radiation treatment when the wetting medium has experienced the decrease in viscosity. 
         [0029]    In a preferred embodiment, the wetting medium is at least partially a gel with a viscosity of at least 7000 cP, preferably at least 25000 cP, before the radiation treatment. Due to the high viscosity, the gel is immobilized in the catheter package and does not come into contact with the hydrophilic outer surface at least along the insertable length of the catheter before and at least initially during the radiation treatment. 
         [0030]    Additionally, it can be provided that the catheter package comprises an open channel diversion for separating the catheter with the hydrophilic outer surface at least along its insertable length and the wetting medium from each other before and during the radiation treatment. The open channel diversion is an additional safeguard to avoid contact between the wetting medium and the hydrophilic outer surface at least along its insertable length of the catheter before and at least initially during the radiation treatment which could damage the hydrophilic outer surface of the catheter and could cause problems when inserting the catheter. Due to the open channel structure, a contact between the outer surface of the catheter and the wetting medium is easily possible after the radiation treatment when the wetting medium has experienced the decrease in viscosity. 
         [0031]    It is also possible to provide the catheter package with at least one welding seam which forms a back taper in the package in which the wetting medium is arranged. This is an easy and economic way to provide an open channel diversion structure in the catheter package which can be easily integrated in the production process of the catheter assembly. The back taper retains the wetting medium before and during the radiation treatment. After the radiation treatment, the low viscous wetting medium can easily flow out of the back taper to the catheter to activate the hydrophilic outer surface at least along the insertable length of the catheter. 
         [0032]    To ensure a very secure separation between the hydrophilic outer surface at least along the insertable length of the catheter and the wetting medium, it can be provided that the catheter with the hydrophilic outer surface at least along its insertable length and the wetting medium are separated by a physical barrier. Such a barrier can, for example, be a clip or another fastener device. 
         [0033]    In still another embodiment, the catheter package comprises a perforated lining which is arranged between the catheter with the hydrophilic outer surface at least along its insertable length and the wetting medium. The high viscosity wetting medium is then held back by the perforated lining during the radiation treatment and can pass through the perforated lining during and/or after the radiation treatment when it has degraded into an aqueous solution with low viscosity. Such a perforated lining can be achieved by welding during the manufacture process and is therefore easy and cost effective. When necessary, external pressure can be applied onto the part of the catheter package behind the perforated lining to squeeze the wetting medium in to the catheter compartment. 
         [0034]    In another embodiment, at least a part of the catheter is surrounded by a sleeve. This sleeve can be used as an introduction aid to insert the activated and thus very slippery catheter into the urethra. Furthermore, the sleeve can be arranged around the external end of the catheter before use so that the wetting medium does not come into contact with these parts of the catheter. 
         [0035]    Furthermore, it can be provided that the wetting medium is partially an aqueous solution and partially a gel which forms a plug to separate the aqueous solution from the catheter with the hydrophilic outer surface at least along its insertable length. This is another way to ensure that the hydrophilic outer surface of the catheter and the wetting medium are kept separate before and at least initially during the radiation treatment of the catheter assembly to avoid degradation of the hydrophilic parts of the catheter which would cause problems during the use of the catheter assembly. 
         [0036]    Furthermore, the catheter assembly can comprise an insertion aid for the catheter which is preferably arranged near the catheter tip. The insertion aid can be a cylindrical part which can be easily gripped by the patient. In this case, the wetting medium is preferably arranged in the insertion aid. After the radiation treatment, the catheter assembly is simply rotated around 180° and the wetting medium then flows out of the introduction aid and along the catheter shaft to activate the hydrophilic outer surface at least along the insertable length of the catheter. 
         [0037]    It is a further object of the present invention to provide a ready-to-use catheter assembly which can be directly used by a patient without the need for activation and wherein the low friction properties of the catheter do not degrade during storage so that a complication-free introduction of the catheter into the urethra is guaranteed during its whole shelf life which ranges from approximately thirty six months to five years. This is achieved by a ready-to-use catheter assembly which comprises a catheter package, a catheter with a hydrophilic outer surface at least along its insertable length arranged in the catheter package and a wetting medium which is also arranged in the catheter packing and which is in contact with the hydrophilic outer surface of the catheter so that the hydrophilic outer surface is activated, wherein the wetting medium is a gel comprising at least one polymer and has a viscosity below 1000 cP, preferably below 100 cp. 
         [0038]    The ready-to-use catheter assembly therefore comprises a pre-activated catheter which can be directly used by the patient. The patient does not have to perform any activating steps which are often cumbersome to perform by a person with reduced dexterity. Furthermore, due to the fact that the activation has been performed during the manufacturing process, it can be guaranteed that the activation has been performed properly and the catheter has a sufficiently slippery surface along the complete insertable length thereof. Therefore, no problems due to high friction occur during the use of the catheter. The desired low viscosity of the wetting medium is achieved by submitting the wetting medium to a radiation treatment where the wetting medium degrades to an aqueous solution. 
         [0039]    It is still a further object of the present invention to provide an easy and secure method to activate a hydrophilic coated catheter. This object is achieved by using a wetting medium for activating the hydrophilic outer surface at least along the insertable length of the catheter whereby the wetting medium experiences a decrease in viscosity when submitted to electro-magnetic and/or particle radiation. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0040]    In the following, the invention is described in more detail with the aid of figures. 
           [0041]      FIG. 1 a    shows a first embodiment of a catheter assembly before a treatment with electro-magnetic and/or particle radiation, 
           [0042]      FIG. 1 b    shows the catheter assembly of  FIG. 1 a    after the radiation treatment and before activation of the hydrophilic outer surface of the catheter, 
           [0043]      FIG. 1 c    shows the catheter assembly of  FIG. 1 a    during activation of the hydrophilic outer surface of the catheter, 
           [0044]      FIG. 2 a    shows a second embodiment of a catheter assembly before a treatment with electro-magnetic and/or particle radiation, 
           [0045]      FIG. 2 b    shows the catheter assembly of  FIG. 2 a    after the radiation treatment and before activation of the hydrophilic outer surface of the catheter, 
           [0046]      FIGS. 2 c  and 2 d    show the catheter assembly of  FIG. 2 a    during activation of the hydrophilic outer surface of the catheter, 
           [0047]      FIG. 3 a    shows a third embodiment of a catheter assembly before a treatment with electro-magnetic and/or particle radiation, 
           [0048]      FIG. 3 b    shows the catheter assembly of  FIG. 3 a    after the radiation treatment and before activation of the hydrophilic outer surface of the catheter, 
           [0049]      FIGS. 3 c  and 3 d    show the catheter assembly of  FIG. 3 a    during activation of the hydrophilic outer surface of the catheter, 
           [0050]      FIG. 4 a    shows a fourth embodiment of a catheter assembly before a treatment with electro-magnetic and/or particle radiation, 
           [0051]      FIG. 4 b    shows the catheter assembly of  FIG. 4 a    after the radiation treatment and before activation of the hydrophilic outer surface of the catheter, 
           [0052]      FIG. 4 c    shows the catheter assembly of  FIG. 4 a    during activation of the hydrophilic outer surface of the catheter, 
           [0053]      FIG. 5 a    shows a fifth embodiment of a catheter assembly before a treatment with electro-magnetic and/or particle radiation, 
           [0054]      FIG. 5 b    shows the catheter assembly of  FIG. 5 a    after the radiation treatment and before activation of the hydrophilic outer surface of the catheter, 
           [0055]      FIG. 5 c    shows the catheter assembly of  FIG. 5 a    during activation of the hydrophilic outer surface of the catheter, 
           [0056]      FIG. 6 a    shows a sixth embodiment of a catheter assembly before a treatment with electro-magnetic and/or particle radiation, 
           [0057]      FIG. 6 b    shows the catheter assembly of  FIG. 6 a    after the radiation treatment and before activation of the hydrophilic outer surface of the catheter, 
           [0058]      FIG. 6 c    shows the catheter assembly of  FIG. 6 a    during activation of the hydrophilic outer surface of the catheter, 
           [0059]      FIG. 7 a    shows a seventh embodiment of a catheter assembly before a treatment with electro-magnetic and/or particle radiation, 
           [0060]      FIG. 7 b    shows the catheter assembly of  FIG. 7 a    after the radiation treatment and before activation of the hydrophilic outer surface of the catheter, 
           [0061]      FIG. 7 c    shows the catheter assembly of  FIG. 7 a    during activation of the hydrophilic outer surface of the catheter, 
           [0062]      FIG. 8 a    shows an eighth embodiment of a catheter assembly before a treatment with electro-magnetic and/or particle radiation, 
           [0063]      FIG. 8 b    shows the catheter assembly of  FIG. 8 a    after the radiation treatment and before activation of the hydrophilic outer surface of the catheter, 
           [0064]      FIG. 8 c    shows the catheter assembly of  FIG. 8 a    during activation of the hydrophilic outer surface of the catheter, 
           [0065]      FIG. 9 a    shows a ninth embodiment of a catheter assembly before a treatment with electro-magnetic and/or particle radiation, 
           [0066]      FIG. 9 b    shows the catheter assembly of  FIG. 9 a    after the radiation treatment and before activation of the hydrophilic outer surface of the catheter, 
           [0067]      FIG. 9 c    shows the catheter assembly of  FIG. 9 a    during activation of the hydrophilic outer surface of the catheter, 
           [0068]      FIG. 10 a    shows a tenth embodiment of a catheter assembly before a treatment with electro-magnetic and/or particle radiation, and 
           [0069]      FIG. 10 b    shows the catheter assembly of  FIG. 10 a    after the radiation treatment and during activation of the hydrophilic outer surface of the catheter. 
       
    
    
     DETAILED DESCRIPTION 
       [0070]      FIG. 1 a    shows a catheter assembly  1  according to the present invention before a treatment with electro-magnetic and/or particle radiation (the radiation treatment). The catheter assembly  1  comprises a catheter package  2 , a catheter  3  and a wetting medium  4 . The catheter  3  and the wetting medium  4  are arranged inside the catheter package  2 . The catheter package  2  is preferably made of an endless film tube which can for example be sealed at both ends. The film tube does not comprise any seams along its longitudinal direction. The catheter package is preferably made of a material that has a low moisture transmission. Examples for materials that can be used are composite or multi-laminated materials comprising materials of aluminum foil, LDPE, MDPE, HDPE, LLDPE or blends of the afore, PP, polyester based polymers (PET), or siloxane coatings. 
         [0071]    The wetting medium  4  experiences a decrease in viscosity when submitted to electro-magnetic and/or particle radiation. For example, the wetting medium can be a gel. In the context of the present patent application, the term “gel” refers to gels, hydrogels, and any high viscous aqueous solutions which contain a polymer or a thixotropic agent.  FIG. 1 a    shows the catheter assembly  1  before the radiation treatment. Therefore, the wetting medium  4  is still in the form of a relative solid exhibiting little or no viscous flow. 
         [0072]    The catheter  3  comprises an inactivated hydrophilic outer surface  5  at least along its insertable length. The catheter  3  and the wetting medium  4  are arranged in the catheter package  2  in such a way that the hydrophilic outer surface  5  remains substantially inactivated. In the present case the wetting medium  4  does not come into contact with at least the hydrophilic outer surface  5  of the catheter  3 . As the wetting medium is relatively solid and exhibits little or no viscous flow, it stays at the position in which it has been placed and does not flow in the direction of the hydrophilic outer surface  5  of the catheter  3 . 
         [0073]    The catheter assembly  1  further comprises a sleeve  6 . The sleeve  6  surrounds the catheter  3  and is placed at the external end of the catheter  3  which lies opposite the catheter tip  7 . At its end facing away from the catheter  3 , the sleeve  6  is folded so that the wetting medium  4  cannot enter the sleeve  6 . 
         [0074]      FIG. 1 c    shows the catheter assembly  1  in the activated state. In the activated state, the wetting medium  4  has dissociated due to electro-magnetic and/or particle radiation and now forms a low viscosity solution which flows along the catheter  3 , thereby coming into contact with the hydrophilic outer surface  5  at least along the insertable length of the catheter  3  and thus activating the hydrophilic outer surface  5 . As can be seen in  FIGS. 1 a  to 1 c   , the catheter package  2  comprises two welding seams  8  on each side of the catheter. These welding seams  8  taper towards the tip of the catheter  3  and thus guide the wetting medium  4  in its aqueous state along the longitudinal direction of the catheter  3 . 
         [0075]      FIG. 2 a    shows a second embodiment of a catheter assembly  10 . The same elements as in the previous embodiment are described with the same reference numbers. In this and the following embodiments, only the differences to the other embodiments are described. The catheter assembly  10  comprises a catheter package  2 , a catheter  3  arranged in the catheter package  2  and a wetting medium  4  also arranged in the catheter package  2 . The catheter package  2  further comprises a welding seam  11  which forms a back taper  12  in the catheter package  2 . In this back taper  12 , the wetting medium  4  is arranged. As the wetting medium  4  is still in its high viscosity, relatively solid state with little or no viscous flow, it remains in this back taper  12 . 
         [0076]      FIG. 2 d    shows the catheter assembly  10  of  FIG. 2 a    after the radiation treatment and during activation of the hydrophilic outer surface  5  of the catheter  3 . The wetting medium  4  is now in its low viscosity state and is an aqueous solution which can freely flow through the catheter package  2 . The wetting medium  4  has therefore left the back taper  12  which is formed by the welding seam  11 , flows around the catheter  3  and is in contact with the hydrophilic outer surface  5  at least along the insertable length of the catheter  3  and activates the hydrophilic outer surface  5  of the catheter  3 . The catheter package  2  is still completely closed so that the activated catheter  3  can be stored in sterile conditions. 
         [0077]      FIG. 3 a    shows a third embodiment of a catheter assembly  14 . The same reference numbers are used for the same elements as described in the two previous embodiments. The catheter assembly  14  comprises a catheter package  2 , a catheter  3  arranged in the catheter package  2  and a wetting medium  4  also arranged in the catheter package  2 . The catheter package  2  comprises two welding seams  15  and  16 . The first welding seam  15  extends transverse to the longitudinal direction of the catheter package  2  and comprises an angle of approximately 45° with the longitudinal direction of the catheter package  2 . The welding seam starts at one side of the catheter package and ends before the second side of the catheter package  2 . Therefore, a back taper  17  is formed by this first welding seam  15 . In this back taper  17 , the wetting medium  4  is placed. As the wetting medium  4  is in its relatively solid state, it remains in the back taper  17  and does not flow in the direction of the catheter  3 . The second welding seam  16  is arranged near the opposite side of the catheter package  2  and extends along the longitudinal direction of the catheter  3 . This second welding seam  16  forms a neck in the catheter package  2  so that the catheter  3  is arranged in a relatively narrow passage of the catheter package  2 . 
         [0078]      FIG. 3 d    shows the catheter assembly  14  of  FIG. 3 a    after the radiation treatment and during the activation of the hydrophilic outer surface  5  of the catheter  3 . The wetting medium  4  is now in its low viscosity state and is an aqueous solution which has exited the back taper  17  formed by the welding seam  15  and flows along the catheter  3 . The second welding seam  16  helps in guiding the aqueous wetting medium  4  to and along the catheter  3 . Thus, the wetting medium  4  comes into contact with the hydrophilic outer surface  5  of the catheter  3  and activates the hydrophilic outer surface  5 . 
         [0079]      FIG. 4 a    shows a fourth embodiment of a catheter assembly  19 . The same reference numbers are used for the same elements as described for the three previous embodiments. Catheter assembly  19  comprises a catheter package  2  and a catheter  3  arranged in the catheter package  2  as well as a wetting medium  4  also arranged in the catheter package  2 . The wetting medium  4  is in its high viscosity state and is arranged at the bottom of the catheter package  2 . 
         [0080]    The catheter  3  is arranged above the bottom of the catheter package  2  so that the hydrophilic outer surface  5  of the catheter  3  is not in contact with the wetting medium  4 . The catheter package  2  comprises a perforated lining  21  which forms a compartment  20  for the wetting medium  4 . The perforated lining  21  can be made by welding separate points of the catheter package  2 . 
         [0081]      FIG. 4 c    shows the catheter assembly  19  of  FIG. 4 a    after the radiation treatment and during activation of the hydrophilic outer surface  5  of the catheter  3 . The wetting medium  4  has degraded and is now in its relatively fluid state. The catheter package  2  has been turned around 180° so that the wetting medium  4  follows the force of gravity in a downwards direction and therefore flows along the longitudinal direction of the catheter  3 , comes into contact with the hydrophilic outer surface  5  of the catheter  3  and thus activates the hydrophilic outer surface  5  of the catheter  3 . 
         [0082]    A fifth embodiment of a catheter assembly  23  is shown in  FIG. 5 a   . The catheter assembly  23  comprises the catheter  3  and the wetting medium  4  which are both arranged in the catheter package  2  so that the wetting medium  4  is not in contact with the hydrophilic outer surface  5  of the catheter  3 . The catheter assembly  23  further comprises an insertion aid  24 . The insertion aid has a cylindrical body  25  which forms a compartment in which the wetting medium  4  is arranged. The insertion aid  24  further comprises a stopper at the side which comes into contact with the urethra when using the catheter. The insertion aid is formed in such a way that it can be easily gripped by a patient with reduced dexterity. The insertion aid  24  is connected to a thin sleeve  26  which extends along the length of the catheter  3  and is connected with a funnel  27  at the exterior end of the catheter  3 . 
         [0083]      FIG. 5 c    shows the catheter assembly  23  after the radiation treatment and during activation of the hydrophilic outer surface  5  of the catheter  3 . The wetting medium  4  now has a low viscosity. The whole catheter package  2  has been turned around so that the wetting medium  4  flows downwardly along the longitudinal direction of the catheter  3  and thus comes into contact with and activates the hydrophilic outer surface  5  of the catheter  3 . The sleeve  26  guides the wetting medium along the catheter  3 . In this way, it can be ensured that the complete area of the hydrophilic outer surface  5  of the catheter  3  is brought into contact with the wetting medium  4  and a complete activation of the hydrophilic outer surface  5  can be guaranteed. 
         [0084]      FIG. 6 a    shows a sixth embodiment of a catheter assembly  38 . The same elements as described in the previous embodiments are referred to with the same reference numbers. Catheter assembly  38  comprises a catheter package  2 , in which a catheter  3  with an inactivated hydrophilic outer surface  5  and a wetting medium  4  are arranged. One end of the catheter  3  is provided with a catheter tip  7  for insertion into the urethra of a patient, the other end of the catheter  3  is provided with a funnel  27 . The wetting medium  4  is arranged in a compartment  39  which is arranged in front of the catheter tip  7  and which can be closed with a cap  40 . Cap  40  is hingedly connected to the compartment  39 . The funnel  27  is connected to a sleeve  26  which extends along the complete length of the catheter  3 . Near the catheter tip  7 , the sleeve  36  is connected to the compartment  39 . When the compartment  39  is closed via the cap  40 , the catheter  3  is completely surrounded by the sleeve  26  and the compartment  39  with the cap  40 . 
         [0085]      FIG. 6 c    shows the catheter assembly  38  after the radiation treatment and during activation of the hydrophilic outer surface  5  of the catheter  3 . The wetting medium  4  is now in its low viscosity state and can therefore easily flow along the catheter  3 . In order to bring the wetting medium  4  in contact with the hydrophilic outer surface  5  of the catheter  3 , the catheter package  2  is turned around 180° so that the wetting medium  4  in its low viscosity state flows out of the compartment  39 , passes the catheter tip  7  and flows downward along the surface of the catheter  3 . Due to the sleeve  26 , the wetting medium  4  is guided closely along the catheter  3  and does not flow through the complete packaging  2 . The cap  40  of the compartment  39  ensures that no wetting medium  4  exits the compartment  39  in the wrong direction. The compartment  39  can serve as an insertion aid when catheter  3  is used. 
         [0086]    A further embodiment of a catheter assembly  42  is shown in  FIG. 7 a   . The same elements as described in the previous embodiments are referred with the same reference numbers. Catheter assembly  42  also comprises a catheter package  2  with a catheter  3  with an inactivated hydrophilic outer surface  5  and a wetting medium  4 . The catheter  3  comprises a funnel  43  at one end. The funnel  43  can be closed with a cap  44 , which is hingedly connected to the funnel  43 . At the other end of the catheter  3 , that is, near the catheter tip  7 , an insertion aid  24  is arranged. The whole catheter  3  is surrounded by a thin sleeve  26 . One end of this sleeve  26  is connected to the funnel  43 , the other end of this sleeve  26  is connected to the insertion aid  24 . The wetting medium  4  is arranged in the insertion aid  24 . 
         [0087]      FIG. 7 c    shows the catheter assembly  42  after the radiation treatment and during activation of the hydrophilic outer surface  5  of the catheter  3 . For activating the hydrophilic outer surface  5  of the catheter  3 , it is brought into contact with the wetting medium  4 . During the radiation treatment, the wetting medium has reduced its viscosity and is now in its low viscosity state. The catheter package  2  has been turned around 180°, so that the insertion aid  24  with the wetting medium  4  arranged therein is now above the catheter  3 . The wetting medium  4  follows the force of gravity and flows downward on the surface of the catheter  3  and thus comes into contact with the hydrophilic coating  5 . The sleeve  26  guides the wetting medium  4  closely along the catheter  3 . The wetting medium  4  can flow through the eyes  45  of the catheter  3  to the interior of the catheter  3 . In order to prevent leakage of the wetting medium  4  past the funnel  43 , the cap  44  is closed and the wetting medium  4  stays inside the catheter  3 . 
         [0088]      FIGS. 8 a  to 8 c    show an eighth embodiment of a catheter assembly  46 . As with all previous embodiments, the same elements as described in the previous embodiments are referred with the same reference numbers. The catheter assembly  46  also comprises a catheter  3  with an inactivated hydrophilic outer surface  5  at least along its insertable length and a wetting medium  4  which are arranged in a catheter package  2 . As shown in  FIG. 8 a   , the wetting medium  4  is placed in the catheter package  2  so that it does not come into contact with the hydrophilic parts of the catheter  3 . The catheter  3  comprises a funnel  27  arranged at one end of the catheter and a catheter tip  7  for introducing the catheter in a urethra of a user on the other end of the catheter  3 . Near the catheter tip  7  an insertion aid  24  is arranged. A thin sleeve  26  is placed around the catheter  3  and is connected at one end with the funnel  27  and at other end with the insertion aid  24 . The catheter  3  is arranged in the catheter package  2  in such a way that the funnel  27  is arranged near the bottom of the catheter package  2 . The wetting medium  4  is arranged inside the sleeve  26  near the funnel  27  near an uncoated section of the catheter  3 . 
         [0089]      FIG. 8 c    shows the catheter assembly  46  after the radiation treatment and before activation of the hydrophilic outer surface  5  of the catheter  3 . During radiation, the wetting medium  4  has experienced a decrease in viscosity and is now in a low viscosity state. The catheter package  2  has been turned around 180°, so that the wetting medium  4  flows downward along the catheter  3  following the force of gravity. The sleeve  26  guides the wetting medium  4  in close proximity to the shaft of catheter  3  so that it comes into contact with the hydrophilic outer surface  5  and activates the hydrophilic outer surface  5 . As the wetting medium  4  is placed near the funnel  27  at the beginning, it does not directly flow into the eyes  45  of the catheter and out of the funnel  27  without activating the hydrophilic outer surface  5  of the catheter  3 . 
         [0090]      FIG. 9 a    shows a ninth embodiment of a catheter assembly  29 . The same elements as described in the previous embodiments are referred to with the same reference numbers. Catheter assembly  29  comprises a catheter package  2 , a catheter  3  with a hydrophilic outer surface  5  and a wetting medium  4 . The wetting medium  4  is placed at one end of the catheter package and the catheter  3  is placed at the opposite end of the catheter package  2 . A physical barrier  30  is fixed to the catheter package  2  between the wetting medium  4  and the catheter  3 . The physical barrier  30  can for example be a clip or a fastener device. In the state of the catheter assembly  29  as shown in  FIG. 9 a   , the wetting medium  4  does not come into contact with the hydrophilic outer surface  5  of the catheter.  FIGS. 9 b  and 9 c    shows the catheter assembly  20  of  FIG. 9 a    after the radiation treatment and during activation of the hydrophilic outer surface  5  of the catheter  3 . The physical barrier  30  has been removed from the catheter package  2  so that the wetting medium  4  which has dissociated during the radiation treatment and is now in its rather liquid state with a low viscosity, can flow freely through the interior of the catheter package  2  and thus comes into contact with the hydrophilic outer surface  5  of the catheter  3 . 
         [0091]    In the embodiments 1 to 9 as described above the wetting medium  4  can be a gel which experiences a non-reversible decrease in viscosity when energy is brought into the system, for example via electro-magnetic and/or particle radiation. The gel then transforms into an aqueous solution which flows through the catheter package  2  and thus activates the hydrophilic outer surface  5  of the catheter  3 . The wetting medium  4  therefore directly activates the hydrophilic outer surface  5  of the catheter  3  at least along its insertable length. It is also possible to use viscoelastic fluids, Bingham fluids, pseudoplastic fluids, dilatant fluids or Newtonian fluids as wetting medium as long as they experience a decrease in viscosity when submitted to external effects. It is also possible that the wetting medium changes its state of matter during the radiation treatment from a solid to a liquid state. In this context, solid state means that the material has a definite shape and volume. Liquid state means that the material has a definite/constant volume and a shape that conforms to the shape of its container. 
         [0092]    In the embodiments as shown in  FIGS. 10 a  and 10 b   , the wetting medium is partly formed of a gel  33  and partly of an aqueous solution  32 . In this tenth embodiment of a catheter assembly  31 , the same reference numbers as used in the description of the previous embodiments are used for the same elements as shown before. The catheter assembly  31  comprises a catheter package  2 , a catheter  3  with an inactivated hydrophilic outer surface  5  and a wetting medium  32 ,  33 . The catheter package  2  is provided with a welding seam  34  which forms a back taper  35  in the catheter package which is connected to the remaining part of the catheter package  2  via a small channel  36 . 
         [0093]    The wetting medium is partly formed of an aqueous solution  32  and partly of a gel-like system  33 . The gel  33  is arranged in the channel  36  and thus forms a plug which holds the aqueous solution  32  in the back taper  35 . The aqueous solution  32  can thus not exit the back taper  35  and is separated from the hydrophilic outer surface  5  of the catheter  3 . 
         [0094]      FIG. 10 b    shows the catheter assembly  31  of  FIG. 10 a    after the radiation treatment and during activation of the hydrophilic outer surface  5  of the catheter  3 . The gel  32  has at least partly dissociated to let the aqueous solution  32  pass. The aqueous solution  32  flows downwardly and is now in contact with the hydrophilic outer surface  5  of the catheter  3  and activates the hydrophilic outer surface  5 . 
         [0095]    In the following, methods for making the ready-to-use catheter assembly as described above are explained in detail. 
         [0096]      FIG. 1 a    shows the catheter assembly  1  before treatment with electro-magnetic and/or particle radiation. The wetting medium  4  is a gel-like system and is in a relatively solid state with a high viscosity so that it exhibits little or no viscous flow. However, as already mentioned above, the wetting medium can be any liquid which reduces its viscosity when external conditions are changed. Examples for such liquids are viscoelastic fluids, Bingham fluids, pseudoplastic fluids, dilatant fluids or Newtonian fluids. The wetting medium can also initially be a solid that changes its state of matter during the radiation treatment from the solid state to to the liquid state. The definition of “solid state” and “liquid state” can be found above. The wetting medium  4  can also be a gel containing a solute polymer, for example Carboxymethyl Cellulose. Other gels, hydrogels or high viscous aqueous solutions which contain a polymer or a thixotropic agent are also possible. The wetting medium  4  is arranged at one end (the bottom) of the catheter package  2  and the inactivated hydrophilic outer surface  5  of the catheter  3  is arranged at the end of the catheter package so that it is not in contact with the wetting medium  4 . In this position, gravity facilitates the separation of the catheter  3  and the wetting medium  4 . 
         [0097]      FIG. 1 b    shows the catheter assembly  1  during a treatment with electro-magnetic and/or particle radiation of the whole assembly. During the radiation treatment, the catheter package  2  remains in the same position as shown in  FIG. 1 a   . The preferred form of radiation is gamma radiation. However, other forms of radiation, i.e. beta radiation, x-ray or UV radiation are possible. The level of radiation lies above the natural background radiation and is high enough so that the viscosity of the wetting medium  4  decreases to allow an activation of the hydrophilic coating. Preferably, the treatment with the electro-magnetic and/or particle radiation is a sterilization step for the whole catheter assembly. The wetting medium  4  can for example be a rigid gel or a hydrogel which comprises a solute polymer in an aqueous solution. 
         [0098]    The wetting medium  4  reduces viscosity during electro-magnetic and/or particle radiation. In  FIG. 1 b   , the wetting medium  4  is shown in its liquid state. The wetting medium  4  has flown to the lower end of the package  2  and remains there separated from the hydrophilic outer surface  5  of the catheter  3  at least along its insertable length. 
         [0099]      FIG. 1 c    shows the activation of the catheter  3 . The whole catheter package  2  is turned around 180° so that the bottom of the catheter package  2  which initially contained the wetting medium  4  is on the top. Following gravity, the wetting medium  4  flows downwardly and comes into contact with the hydrophilic outer surface  5  of the catheter  3 . In this way, the hydrophilic outer surface  5  of the catheter  3  is activated. As the welding seam  8  tapers towards the catheter tip  7  and the wetting medium  4  is guided along the catheter  3  it comes into intimate contact with the hydrophilic outer surface  5  and ensures a good activation. 
         [0100]    The method for making a ready-to-use catheter assembly according to the second embodiment for the catheter assembly  10  as shown in  FIGS. 2 a  to 2 d    functions basically as described above. In  FIG. 2 a   , the catheter assembly  10  is shown before the radiation treatment. The wetting medium  4  is still in its relatively high viscosity state and is arranged in the back taper  12  at the bottom of the catheter package  2 . The catheter  3  with its inactivated hydrophilic outer surface  5  is arranged above the wetting medium  4  and is separated from the wetting medium  4  by the welding seam  11 .  FIG. 2 b    shows the treatment of the catheter assembly  10  with electro-magnetic and/or particle radiation. Preferably, this step is a radiation sterilization, preferably by gamma sterilization as described above and the wetting medium  4  is a gel which experiences a non-reversible decrease in viscosity when submitted to electro-magnetic and/or particle radiation. The wetting medium  4  therefore dissociates during radiation and flows along the bottom of the package  2 , guided by the welding seam  11 . 
         [0101]      FIGS. 2 c  and 2 d    show the activation of the hydrophilic outer surface  5  of the catheter  3 . In a first step, as shown in  FIG. 2 c   , the catheter package  2  is rotated around an angle of 90°. The wetting medium  4  flows out of the back taper  12  and follows the welding seam  11  through the top of the catheter package. In the second step, as shown in  FIG. 2 d   , the catheter package  2  is rotated around an angle of 180° so that the wetting medium  4  is now in contact with the hydrophilic outer surface  5  of the catheter  3  and thus activates the hydrophilic outer surface  5 . 
         [0102]      FIGS. 3 a  to 3 d    show the radiation treatment and the activation of the catheter assembly  14  according to the third embodiment.  FIG. 3 a    shows the catheter assembly  14  before radiation treatment. The wetting medium  4  is arranged in the back taper  15  at the bottom of the catheter package  2  and has a high viscosity. In  FIG. 3 b   , the radiation treatment is shown. The complete catheter assembly  14  is submitted to electro-magnetic and/or particle radiation, preferably gamma radiation. Preferably, the complete assembly is sterilized in this step. During the radiation treatment, the wetting medium  4  decreases in viscosity as described in the first embodiment and turns into aqueous solution. As the catheter package  2  remains in the position as shown in  FIG. 3 a   , the wetting medium  4  remains at the bottom of the catheter package  2 . 
         [0103]      FIG. 3 c    shows the first step of activating the hydrophilic outer surface  5  of the catheter  3 . The catheter package  2  is rotated around an angle of 90° and the wetting medium  4  flows along the welding seam  15  out of the back taper  17  in the direction of the catheter  3 . The catheter package  2  is then again rotated around an angle of 90° (see  FIG. 3 d   ) and the wetting medium  4  flows downwardly along the welding seam  16  and comes into contact with the catheter  3  and thus activates the hydrophilic outer surface  5  of the catheter  3 . 
         [0104]      FIGS. 4 a  to 4 c    show the method for a radiation treatment and an activation for the fourth embodiment of the catheter assembly  19 . In  FIG. 4 a   , the catheter assembly  19  is shown before the radiation treatment. The wetting medium  4  is still in its high viscosity state and remains at the bottom of the catheter package  2  separated from the catheter  3  with the hydrophilic outer surface  5  via gravity. In  FIG. 4 b   , the complete catheter assembly is irradiated with electro-magnetic and/or particle radiation, for example sterilized via radiation sterilization. Due to the radiation treatment, the wetting medium  4  reduces viscosity and turns into an aqueous solution. The catheter package  2  remains in the position as shown in  FIG. 4 a   . In  FIG. 4 c   , the catheter package  2  is rotated around an angle of 180° and the wetting medium  4  flows through the perforated lining  21  downwardly and comes into contact with the hydrophilic outer surface  5  of the catheter  3  and thus activates the hydrophilic outer surface  5 . 
         [0105]    The same method is shown in  FIGS. 5 a  to 5 c    for the fifth embodiment of the invention. In this embodiment, the wetting medium  4  is arranged in the insertion aid  25 . In  FIG. 5 a   , which shows the catheter assembly  23  before the radiation treatment, the wetting medium  4  and the catheter  3  with its inactivates hydrophilic outer surface  5  are separated from each other. In  FIG. 5 b   , the whole catheter assembly  23  is submitted to gamma radiation so that the assembly is sterilized and the wetting medium  4  degrades into an aqueous solution. After that, the catheter package  2  is rotated around an angle of 180° as shown in  FIG. 5 c   . The wetting medium  4 , which now has a low viscosity, flows downwardly along the catheter  3  and comes into contact with the hydrophilic outer surface  5  of the catheter  3  and activates the hydrophilic outer surface  5 . 
         [0106]      FIGS. 6 a  to 6 c    show the method for making the catheter assembly  38  according to the sixth embodiment of the invention.  FIG. 6 a    shows the catheter assembly  38  before the radiation treatment. The wetting medium  4  is still in its high viscosity state and placed in the compartment  39  which is arranged below the catheter  3  with the hydrophilic outer surface  5 . 
         [0107]      FIG. 6 b    shows the complete catheter assembly  38  during the radiation treatment. The complete catheter assembly  38  is submitted to electro-magnetic or particle radiation and is thereby sterilized. Due to the radiation, the wetting medium  4  reduces its viscosity and turns into its low viscosity state. The catheter assembly  38  is still in its first position wherein the compartment  39  with the wetting medium  4  is arranged below the catheter  3 . 
         [0108]      FIG. 6 c    shows the activation of the hydrophilic outer surface  5  of the catheter  3 . The complete catheter assembly  38  is turned around 180° so that the compartment  39  with the wetting medium  4  is now arranged above the catheter  3 . Following the force of gravity, the wetting medium  4  in its low viscosity state flows downwards along the catheter  3 . The sleeve  26  guides the wetting medium  4  closely along the catheter  3  with the hydrophilic outer surface  5 . Thereby, the hydrophilic outer surface  5  of the catheter  3  comes into contact with the wetting medium medium  4  and is activated. When the compartment  39  is closed with the hinge cap  40 , the catheter  3  is completely sealed in the sleeve  26 . 
         [0109]      FIGS. 7 a , 7 b  and 7 c    show the activation of the hydrophilic outer surface  5  of the catheter  3  for the seventh embodiment of the invention.  FIG. 7 a    shows the catheter assembly  42  before the radiation treatment. The catheter  3  is arranged in the catheter package  2  so that the catheter tip  7  faces the bottom of the catheter package  2 . The wetting medium  4  is arranged in the insertion aid  24  and thus arranged below the catheter  3  with the hydrophilic outer surface  5 . The funnel  43  can be closed with the cap  44  to prevent leakage of the wetting medium  4 . 
         [0110]      FIG. 7 b    shows the catheter assembly  42  during and after the radiation treatment but before activation of the hydrophilic outer surface  5  of the catheter  3 . During the radiation treatment, the wetting medium  4  turns into its low viscosity state due to the energy provided by the radiation. As the wetting medium  4  is arranged near the bottom of the catheter package  2 , it remains there also in its low viscosity state. The wetting medium  4  and the hydrophilic outer surface  5  of the catheter  3  thus do not come into contact. In order to activate the hydrophilic outer surface  5  of the catheter  3 , the catheter assembly  42  is rotated around an angle of 180° as shown in  FIG. 7 c   . The wetting medium  4  in its low viscosity state is guided by the sleeve  26  downwardly along the catheter  3 , comes into contact with the hydrophilic outer surface  5  and activates the hydrophilic outer surface  5 . As the funnel  43  is closed by the cap  44 , the wetting medium  4  cannot exit and leakage is prevented. 
         [0111]      FIGS. 8 a , 8 b  and 8 c    show the activation method for the eight embodiment of the invention.  FIG. 8 a    shows the catheter assembly  46  before the radiation treatment. The catheter  3  with the sleeve  26  and the insertion aid  24  is arranged in the catheter package  2  so that the funnel  27  faces towards the bottom. The wetting medium  4  is placed inside the sleeve  26  near the funnel  27 . The surface of the catheter  3  in the region where the wetting medium  4  is arranged does not need to be coated. During electromagnetic and/or particle radiation, the catheter package  2  remains in the position as shown in  FIG. 8 a   . This is shown in  FIG. 8 b   . Due to the energy submitted to the system during electro-magnetic and/or particle radiation, the wetting medium  4  reduces its viscosity and turns into its low viscosity state. Under the force of gravity, the wetting medium  4  stays near the funnel  27 . As the catheter tip  7  is arranged at the top of the catheter package  2 , the wetting medium  4  cannot flow through the eyes  45  of the catheter  3 . For activating the hydrophilic outer surface  5  of the catheter  3 , the complete catheter assembly  46  is rotated around 180° so that the funnel  27  is now above the catheter  3  and the catheter tip  7  faces the bottom. Following the force of gravity, the wetting medium  4  flows downwardly along the catheter  3 , and thus comes into contact with and activates the hydrophilic outer surface  5  of the catheter  3 . Due to this arrangement, it is thus prevented that after the radiation treatment, the wetting medium in its low viscosity state flows directly into the eyes  45  of the catheter and out of the funnel  27  without activating the hydrophilic outer surface  5 . 
         [0112]    In  FIGS. 9 a  to 9 c   , the sterilizing method for the ninth embodiment of the invention is shown.  FIG. 9 a    shows the catheter assembly  29  before the radiation treatment. The wetting medium  4  is still in its high viscosity state and is separated from the catheter  3  by a physical barrier  30 . In  FIG. 9 b    the complete catheter assembly is submitted to radiation and is thereby sterilized and the wetting medium  4  turns into an aqueous solution. The physical barrier  30  is then removed and the catheter package  2  is turned around an angle of 180° (see  FIG. 6 c   ). The wetting medium  4  flows along the catheter  3  thereby coming into contact with and activating the hydrophilic outer surface  5  of the catheter  3 . 
         [0113]    In all the embodiments as described above, the viscosity of the wetting medium  4  before the radiation treatment with electro-magnetic and/or particle radiation, that is the gel, is at least 7000 cP, preferably at least 25000 cP. During the radiation treatment, when the wetting medium  4  is submitted to electro-magnetic and/or particle radiation, the viscosity of the wetting medium  4  decreases by at least 80%, preferably at least 90%. 
         [0114]    In a preferred embodiment for the wetting medium  4 , the viscosity of the wetting medium after the treatment with electro-magnetic and/or particle radiation is smaller than 1000 cP, preferably smaller than 100 cP. The viscosity of the wetting medium (gel) was measured using a Brookfield viscometer. The sample was placed below the spindle and the spindle was lowered into the sample to a set point. 
         [0115]    The spindle rotates at a specific speed (30 rpm) and the resistance of the gel correlates to the viscosity. The spindle used was LV4, #64. The temperature at the test was 25° C. 
         [0116]    In  FIGS. 10 a  and 10 b   , the wetting medium (gel) is used as an activation aid and forms a plug  33  for an aqueous solution  32  before the radiation treatment (see  FIG. 10 a   ). During the radiation treatment the gel  33  reduces viscosity sufficiently, flows downwardly in the direction of the catheter  3  together with the aqueous solution  32  so that at least the aqueous solution  32  comes into contact with the hydrophilic outer surface  5  of the catheter  3  and thus activates the catheter  3 . Before the radiation treatment, the viscosity of the gel  33  is at least 7000 cP. In this embodiment, a viscosity decrease due to the radiation treatment with electro-magnetic and/or particle radiation of approximately 10% is sufficient, because the plug formed by the gel  33  only needs to deform to let the aqueous solution  32  pass. The viscosity of the gel  33  is determined as described for the previous embodiments. 
         [0117]    The methods for making the ready-to-use catheter assembly are described only for a wetting medium which initially is in the form of a gel. As described earlier, the wetting medium can be any liquid which reduces its viscosity when external conditions are changed, for example viscoelastic fluids, Bingham fluids, pseudoplastic fluids, dilatant fluids or Newtonian fluids. It is also possible to use a wetting medium which initially is a solid and which experiences a change of state of matter during the radiation treatment from the solid state to the liquid state. 
       LIST OF REFERENCE NUMBERS 
       [0000]    
       
           1 : Catheter assembly 
           2 : Catheter package 
           3 : Catheter 
           4 : Wetting medium 
           5 : Hydrophilic outer surface 
           6 : Sleeve 
           7 : Catheter tip 
           8 : Welding seam 
           10 : Catheter assembly 
           11 : Welding seam 
           12 : Back taper 
           14 : Catheter assembly 
           15 : Welding seam 
           16 : Welding seam 
           17 : Back taper 
           19 : Catheter assembly 
           20 : Compartment 
           21 : Perforated lining 
           23 : Catheter assembly 
           24 : Insertion aid 
           25 : Cylindrical body 
           26 : Sleeve 
           27 : Funnel 
           29 : Catheter assembly 
           30 : Physical barrier 
           31 : Catheter assembly 
           32 : Wetting medium aqueous solution 
           33 : Wetting medium gel 
           34 : Welding seam 
           35 : Back taper 
           36 : Channel 
           38 : Catheter assembly 
           39 : Compartment 
           40 : Cap 
           42 : Catheter assembly 
           43 : Funnel 
           44 : Cap 
           45 : Catheter eyes 
           46 : Catheter assembly