Patent Publication Number: US-2023138293-A1

Title: Urinary Catheters with Improved Shape Recovery and Ease of Use

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Application Ser. No. 62/989,277, filed Mar. 13, 2020, the disclosure of which is hereby incorporated by reference in its entirety. 
    
    
     DESCRIPTION 
     Technical Field 
     The present disclosure generally relates to catheters comprised of a thermoplastic polyurethane, and more particularly, for catheters with thermoplastic polyurethane polymer tubing that have a high percentage of recovery after storage in a coiled configuration. 
     Background 
     Catheters are used to treat many different types of medical conditions and typically include an elongated catheter shaft that is inserted into and through a passageway or lumen of the body. Catheters, and in particular intermittent catheters, are commonly used by those who suffer from various abnormalities of the urinary system, such as urinary incontinence. 
     Urinary catheters generally comprise a catheter shaft. The catheter shaft includes a proximal end having a tip that is inserted into and through a user&#39;s urethra. The catheter shaft also includes a distal end that includes a drainage member, which may be a funnel or connector that facilitates drainage of bodily fluids for the catheter shaft. 
     For discreet storage and carrying, it may be desirable to store catheters in a package in a coiled or circular configuration. The catheter assembly is packaged, sterilized and stored for a number of days to months, before use. Oftentimes, after removal from the packaging, the catheter undesirably retains its coiled shape, and it may take time and effort for the catheter to recover to its pre-coiled shape. This can be especially troublesome for users that have limited dexterity. 
     For various reasons, including but not limited to efficiency, effectiveness and ease of use, it is desirable to provide a catheter tubing material with a higher percentage recovery after storage in a substantially coiled configuration. 
     Therefore, there remains a need for catheters that have sufficient shape recovery. 
     SUMMARY 
     There are several aspects of the present subject matter which may be embodied separately or together in the devices and systems described and claimed below. These aspects may be employed alone or in combination with other aspects of the subject matter described herein, and the description of these aspects together is not intended to preclude the use of these aspects separately or the claiming of such aspects separately or in different combinations as set forth in the claims appended hereto. 
     In one aspect, a catheter product includes a package defining a cavity and a catheter including a thermoplastic polyurethane polymer tubing contained within the cavity of the package, wherein at least a portion of the tubing is in a substantially arcuate configuration within the cavity. The portion of the polymer tubing is defined between a proximal location on the polymer tubing and a distal location on the polymer tubing. The portion of the polymer tubing has a shape recovery after 1 month at room temperature of at least 35%. The percent shape recovery of the portion of the tubing is calculated by the formula: percent shape recovery=[1−(L0−L2)/(L0-L1)]×100, where L0 is the length of the portion of the polymer tubing as measured from the proximal location to the distal location when in a straight configuration, L1 is the diameter of curvature of the portion of the tubing when in the arcuate configuration within the cavity, and L2 is the distance between the proximal location and distal location of the portion of the tubing after removal from the arcuate configuration. 
     In another aspect, a method for making a urinary catheter product with improved shape recovery includes annealing a thermoplastic polyurethane tubing of a catheter for at least 2 hours at 100 C and placing the catheter in a substantially arcuate configuration within a cavity of a package, wherein at least a portion of the tubing is in a substantially arcuate configuration within the cavity, the portion of the polymer tubing being defined between a proximal location on the tubing and a distal location on the tubing. The portion of the polymer tubing has a shape recovery after 1 month at room temperature of at least 35%. The percent shape recovery of the portion of the tubing is calculated by the formula: percent shape recovery=[1−(L0−L2)/(L0−L1)]×100, where L0 is the length of the portion of the polymer tubing as measured from the proximal location to the distal location when in a straight configuration, L1 is the diameter of curvature of the portion of the tubing when in the arcuate configuration within the cavity, and L2 is the distance between the proximal location and distal location of the portion of the tubing after removal from the arcuate configuration. 
     In another aspect, an intermittent urinary catheter includes a thermoplastic polyurethane polymer tubing wherein at least a portion of the tubing has an initial straight configuration, a substantially arcuate configuration, and a recovery configuration. The portion of the polymer tubing is defined between a proximal location of the tubing and a distal location of the tubing. The recovery configuration has a shape recovery after being in the arcuate configuration for 1 month at room temperature of at least 35%. The percent shape recovery of the portion of the tubing is calculated by the formula: percent shape recovery=[1−(L0−L2)/(L0−L1)]×100, where L0 is the length of the portion of the polymer tubing as measured from the proximal end to the distal end when in a straight configuration, L1 is the diameter of curvature of the portion of the tubing when in the arcuate configuration, and L2 is the distance between the proximal location and distal location of the tubing after removal from the arcuate configuration and in the recovery configuration. 
     In another aspect, a catheter product includes a package defining a cavity and a catheter including a thermoplastic polymer tubing contained within the cavity of the package, wherein at least a portion of the tubing is in a substantially arcuate configuration within the cavity. The portion of the polymer tubing is defined between a proximal location on the polymer tubing and a distal location on the polymer tubing. The portion of the polymer tubing has a shape recovery after 1 month at room temperature of at least 35%. The percent shape recovery of the portion of the tubing is calculated by the formula: percent shape recovery=[1−(L0−L2)/(L0−L1)]×100, where L0 is the length of the portion of the polymer tubing as measured from the proximal location to the distal location when in a straight configuration, L1 is the diameter of curvature of the portion of the tubing when in the arcuate configuration within the cavity, and L2 is the distance between the proximal location and distal location of the portion of the tubing after removal from the arcuate configuration. The storage modulus (E′) of the polymer tubing is greater than or equal to 19 MPa and less than or equal to 50 MPa and the loss modulus (E″) of the polymer tubing is greater than or equal to 2.8 MPa and less than or equal to 8.9 MPa. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    includes a top view of a catheter according to one embodiment of the current disclosure. 
         FIG.  2    includes a top view of a catheter product according to one embodiment of the current disclosure. 
         FIG.  3    includes a top view of a catheter according to one embodiment of the current disclosure. 
         FIG.  4    includes a top view of a catheter product according to one embodiment of the current disclosure. 
         FIG.  5    includes a schematic illustration of dimensional measurements for calculating percent recovery. 
         FIG.  6    includes a schematic illustration of three catheter types after unpacking from a first pack size. 
         FIG.  7    includes a schematic illustration of three catheter types after unpacking from a second pack size. 
         FIG.  8    includes a schematic illustration of three catheter types after unpacking from a third pack size. 
     
    
    
     DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS 
     The embodiments disclosed herein are for the purpose of providing a description of the present subject matter, and it is understood that the subject matter may be embodied in various other forms and combinations not shown in detail. Therefore, specific embodiments and features disclosed herein are not to be interpreted as limiting the subject matter as defined in the accompanying claims. 
     The present disclosure is directed to catheters that include tubing that may be inserted into and advanced within a lumen of a body, such as a urethra. 
     The catheters of the present disclosure include tubing that is made from a polymer material(s). The polymer material can be polyurethane, specifically a thermoplastic polyurethane. Thermoplastic polyurethanes can be polyester, polyether, or polycaprolactone based and can be aromatic or aliphatic. One or more of these thermoplastic polyurethanes may be utilized in the current embodiments. In an embodiment according to the current disclosure, the thermoplastic polyurethane is an aromatic polyether thermoplastic polyurethane. Blends of different thermoplastic polyurethanes or blends of different polymers, including polymers such as polyvinyl chloride (PVC) and thermoplastic elastomers (TPE) may also be used. 
     The shore hardness of the polymer tubing may be in the range of 80 A-95 A, preferably at least 80 A, or at least 88 A, or at least 90 A. In one embodiment, the shore hardness is in the range of 88 A-91 A. Hardness is calculated per the ASTM D2240 test method and tested with a durometer. 
       FIG.  1    illustrates a urinary catheter  50  having catheter polymer tubing  60  made from any of the above-discussed polymers. Catheter tubing  60  may have an arcuate configuration, such as a coiled, wound, bent or curved configuration. In the coiled configuration, the catheter may be in a circular, oval or elliptical configuration. For example, the catheter tubing  60  may be wound or coiled into the coiled configuration shown in  FIG.  1   . The catheter  50  may be any suitable urinary catheter used for bladder drainage. The catheter  50  has a proximal end  91  which can include an introducer tip for insertion and a distal end  92  which can include a drainage member or funnel. In the illustrated embodiment, catheter  50  includes catheter tubing  60  having a portion  40  defined between a proximal location  20  and a distal location  30 . Portion  40  has a diameter of curvature  11 . 
     The catheter  50  may be a hydrophilic catheter and catheter tubing  60  may include a hydrophilic coating. When the hydrophilic coating is wetted or hydrated with a hydration medium, such as water, it becomes lubricious which eases introduction of the device into the body and aids in reducing pain and discomfort associated with such introduction. The hydrophilic coating can be a single layer or multilayer hydrophilic coating. Multiple layered coating can include at least a base coat and top layer. 
     Catheter  50 , optionally, also may include a thin flexible sleeve that covers at least a section of the outer surface of the catheter tube  60 . The sleeve may be formed of any variety of thin flexible polymeric film materials, such as polyethylene, plasticized PVC, polypropylene, polyurethane or elastomeric hydrogels. When catheter tube  16  includes a hydrophilic coating thereon, the sleeve may be liquid and/or vapor permeable so as to allow liquid and/or vapor therethrough to hydrate the hydrophilic coating while catheter  50  is stored within package  80 . Alternatively, the sleeve may include a hydration liquid or a foamed hydration liquid within the sleeve and in contact with the hydrophilic material. 
     The urinary catheter may be part of a catheter product that includes a package  70  as shown in  FIG.  2   . Catheter package  70  includes catheter  50  within a cavity  81  of package  80 . Wound or coiled catheter tube  60  may be single or multiply wound or coiled, depending on the size of the package and the type of catheter. Male urinary catheters typically have longer tubing, while female urinary catheters are typically short. An example of a longer catheter tubing and its packaging are included in  FIGS.  1  and  2   . An example of a shorter catheter tubing and its packaging are included in  FIGS.  3  and  4   . 
     Package  80  is preferably liquid and gas impermeable and may be made from any suitable liquid and gas impermeable materials, such as foils, polymers or multilayer films or laminates containing layers of metallic and/or polymer materials. In one embodiment, the package is made from aluminum foil. In another embodiment, the package is made from a polymer film. In yet another embodiment the package is made from a multilayered film including a polymer overlaying a foil, such as polypropylene covered aluminum foil. 
     In the embodiment illustrated in  FIG.  2   , package  80  is generally rectangular. The package also may be shapes other than rectangle. For example, the package  80  may be generally round (e.g. circular, oval, ellipse, etc.) or generally square. 
     When catheter  50  is a hydrophilic catheter, package  80  may include one or more sources for hydrating the hydrophilic surface of the catheter while the catheter is stored within the package. An amount of hydration liquid, or wetting fluid, for contacting and hydrating the hydrophilic surface of the catheter  50  may be contained (or provided) within cavity  81  of package  80 . In an alternative embodiment, an amount of vapor donating liquid that provides a hydration vapor for vapor hydrating the hydrophilic surface of the catheter  50  may be disposed within cavity of package  80 . The hydration liquid, or wetting fluid, may include water and a number of additives. Additives can include stability compounds or antioxidants including, but not limited to, glycerol, topherols, and ascorbic acid. 
       FIGS.  3  and  4    show a shorter length catheter  500  and a catheter package  700 . Catheter  500  may have the same features as catheter  50  disclosed above except that it is much shorter in length because it is designed to be used by females (who have a much shorter urethra than males). Packaging  800  may have the same features as package  80  as described above. In this embodiment, catheter  500  has an arcuate configuration, such as a compact bent, curved or arcuate configuration, when placed within cavity  810  of the package  800 . The catheter  500  has a proximal end  910  for insertion and a distal end  920  which can include a drainage member or funnel. In the illustrated embodiment, catheter  500  includes an elongated catheter tube  600  having a portion  400  between a proximal location  200  and a distal location  300 . Portion  400  has a diameter of curvature  11 . 
     The catheters and/or catheter tubing of the current disclosure may be annealed to improve characteristics of the polymer tubing. Annealing is a heating process used to alter the characteristics of a compound. According to some embodiments of the current disclosure, the catheter and/or catheter tubing may be annealed for at least 2 hours at 100 C. In additional embodiments, the catheter and/or catheter tubing may be annealed for at least 20 hours at 100 C. 
     The catheters and catheter packages of the present disclosure may be sterilized prior to use. The catheter packages may be sterilized by applying a sufficient amount of radiation, such as gamma or E-Beam radiation. In one embodiment, the packages are electron beam sterilized at 10 MeV with a dose in the range of 25-65 kGy. The catheter packages can be sterilized with radiation while the hydrophilic coating is in contact with the wetting fluid. 
       FIG.  5    illustrates the dimensional measurement for calculating percent recovery for a portion of catheter tubing. A portion  13  of the catheter, which may be the entire catheter tubing or a portion of the catheter tubing, has an initial length  10 , L0, as measured from a proximal location to a distal location when in a straight configuration. In the arcuate configuration, such as in a coiled configuration, after packaging, the portion  13  has a diameter of curvature  11 , L1. As shown in  FIGS.  1  and  3   , the portion can form a coiled or curved configuration. Additionally, the portion can form any shape with a curved portion, including, but not limited to, an oval or ellipse. When the coil is a substantially circular configuration, the diameter of curvature may be the diameter of the substantially circular configuration. When the tube is in curved configurations, the diameter of curvature may be the major or minor axis of the curved configuration. After removal from the arcuate configuration, the portion  13  has a distance L2 between the proximal location and distal location. 
     EXAMPLES 
     Example 1 
     Thermoplastic Urethane (TPU, Pellethane®), Polyvinyl Chloride (PVC), and Styrene-Ethylene-Butylene-Styrene/Polypropylene (SEBS/PP) Based Thermoplastic Elastomer (TPE) CH14 catheter tubing materials of different shore hardness (A) were packed in coiled configurations with three different lengths of the portion of the polymer tubing as measured from the proximal location to the distal location when in a straight configuration (L0=78.5, 122, and 166.5). The tubing material was fastened in the coiled configuration. Prior to packing, some samples were annealed (indicated by ann). Annealing was carried out at 100° C. for 20 hours in a vertical position with a metal rod inside the lumen of the tube, the rod had a diameter smaller than the inner diameter of the tubing. Approximately 4 mL of water was added to each pack. Each pack was sealed and electron beam sterilized at 10 MeV with a dose in the range of 25-65 kGy. The packs were stored for 1 month at room temperature. After 1 month, the samples were freely hung for 2 minutes and then the length of the partially curved catheter portion (L2) measurement was taken. 
     Percent recovery was calculated using the formula: percent recovery=[1−(L0−L2)/(L0−L1)]×100. Where L0 is the length of the portion of the polymer tubing as measured from the proximal location to the distal location when in a straight configuration, L1 is the diameter of curvature of the portion of the tubing when in the coiled configuration within the cavity, and L2 is the distance between the proximal location and distal location of the portion of the tubing after removal from the coiled configuration. 
     Table 1 shows the % recovery for L0=78.5 mm. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 1 
               
               
                   
               
               
                   
                   
                   
                 % 
               
               
                 Material 
                 L1 
                 L2 
                 recovery 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 Pellethane 2363-90AE 
                 52.0 
                 64.3 
                 46 
               
               
                 Pellethane 2363-90AE ann. 
                 51.0 
                 70.1 
                 69 
               
               
                 Pellethane 2363-80AE 
                 51.0 
                 68.5 
                 64 
               
               
                 Pellethane 2363-80AE ann. 
                 52.0 
                 70.5 
                 70 
               
               
                 PVC 82A 
                 51.0 
                 60.0 
                 33 
               
               
                 TPE 83A 
                 49.0 
                 65.5 
                 56 
               
               
                   
               
            
           
         
       
     
     Table 2 shows the % recovery for L0=122 mm. 
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 2 
               
               
                   
                   
               
               
                   
                 Material 
                 L1 
                 L2 
                 % recovery 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 Pellethane 2363-90AE 
                 78 
                 96 
                 41 
               
               
                   
                 Pellethane 2363-90AE ann 
                 77 
                 110 
                 73 
               
               
                   
                 Pellethane 2363-80AE 
                 78 
                 104 
                 59 
               
               
                   
                 Pellethane 2363-80AE ann 
                 79 
                 112 
                 77 
               
               
                   
                 PVC 82A 
                 77 
                 91 
                 31 
               
               
                   
                 TPE 83A 
                 77 
                 101 
                 53 
               
               
                   
                   
               
            
           
         
       
     
     Table 3 shows the % recovery for L0=166.5 mm. 
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 3 
               
               
                   
                   
               
               
                   
                 Material 
                 L1 
                 L2 
                 % recovery 
               
               
                   
                   
               
             
            
               
                   
                 Pellethane 2363-90AE 
                 107 
                 137 
                 50 
               
               
                   
                 Pellethane 2363-90AE ann 
                 106 
                 150 
                 73 
               
               
                   
                 Pellethane 2363-80AE 
                 112 
                 147 
                 64 
               
               
                   
                 Pellethane 2363-80AE ann 
                 106 
                 157 
                 85 
               
               
                   
                 PVC 82A 
                 112 
                 135 
                 42 
               
               
                   
                 TPE 83A 
                 103 
                 134 
                 49 
               
               
                   
                   
               
            
           
         
       
     
     Example 2 
     Polyvinyl Chloride (PVC), Thermoplastic Elastomer (TPE), and polyolefin based elastomers (TPO) CH14 tubing materials of different shore hardness (A) were packed in coiled configurations in a medium package (L1=122). The tubing material was coiled in the package. Approximately 4 mL of water was added to each pack. Each pack was sealed and electron beam sterilized at 10 MeV with a dose in the range of 25-65 kGy. The packs were stored for 4 months at room temperature. L2 was measured after removal from the coiled configuration. Table 4 shows the percent recovery for each catheter tube. 
     
       
         
           
               
               
               
             
               
                   
                 TABLE 4 
               
               
                   
                   
               
               
                   
                   
                 Recovery 
               
               
                   
                 Material 
                 [%] 
               
               
                   
                   
               
             
            
               
                   
                 PVC 82A 
                 26 
               
               
                   
                 PVC 91A 
                 14 
               
               
                   
                 TPO 80A 
                 10 
               
               
                   
                 TPO 90A 
                 10 
               
               
                   
                 TPE 83A 
                 26 
               
               
                   
                 TPE 90A 
                 14 
               
               
                   
                   
               
            
           
         
       
     
     Example 3 
     Different TPU (including commercially available Texin® and Pellethane®), PVC, and TPE CH14 tubing materials of varying shore hardness (A) were packed in coiled configurations with L0=141 mm. The tubing material was placed in a coiled metal jig that had a circular channel. The tubing material was placed in the channel of the jig, such that the channel held the tubing in the circular configuration. TPU samples were annealed. Annealing was carried out at 100° C. for 2 hours or 20 hours in a vertical position with a metal rod inside the lumen of the tube, the rod had a diameter smaller than the inner diameter of the tubing. 
     The tensile storage modulus (E′) and loss modulus (E″) was measured in the temperature range −60° C. to 70° C. at 1 Hz approximately 7 days after annealing. For viscoelastic materials, the storage modulus is proportional to the stored energy for the elastic portion of the material, and the loss modulus is proportional to the energy dissipated as heat for the viscous portion of the material. A Dynamic Mechanical Analyzer TA Instruments DMA Q800, available from TA Instruments, Inc., of New Castle, Del.; equipped with a film clamp and Thermal Advantage DMA Q800 V7.5 Build 127 software for data acquisition was used for measuring the storage modulus (E′) and loss modulus (E″). The test parameters that were used include: frequency of 1 Hz, oscillation amplitude of 25.0, static force of 0.0100 N, force track at 125.0% and minimum oscillation force at 0.02000 N. The catheter tubing was cut into a 33 mm long section. That section was bisected along its axis. One half of the bisected tubing, having a length of 33 mm and a width of 6.5 mm, was used as the sample for the testing. The mechanical properties were then analysed using the instruments described above with the multi-frequency strain experimental program method. The experimental method steps include: turning data storage off, equilibrating at −65° C., maintaining isothermal state for 5 minutes, turning data storage on, and ramping temperature 2° C./min to a temperature of 70° C. The program halts and saves the collected data once the temperature of 70° C. has been reached during the temperature ramp step. 
     Tube samples were stored in the coiled shape for 6 weeks at 40° C. Samples were removed from the oven and equilibrated at room temperature for a minimum of 1 hour prior to uncoiling and taking the L2 measurement. Table 5 shows the percent recovery and storage modulus. 
     
       
         
           
               
               
               
               
               
               
               
             
               
                 TABLE 5 
               
               
                   
               
               
                   
                   
                   
                   
                 % 
                 E′ 
                 E″ 
               
               
                 Material 
                 L0 
                 L1 
                 L2 
                 recovery 
                 [MPa] 
                 [MPa] 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 Pellethane 2363- 
                 141 
                 90 
                 109 
                 37 
                 26 
                 5.1 
               
               
                 90AE not ann 
                   
                   
                   
                   
                   
                   
               
               
                 Pellethane 2363- 
                 141 
                 90 
                 115 
                 49 
                 19 
                 2.8 
               
               
                 90AE ann 2 h 
                   
                   
                   
                   
                   
                   
               
               
                 Pellethane 2363- 
                 141 
                 90 
                 116 
                 51 
                 19 
                 2.8 
               
               
                 90AE ann 20 h 
                   
                   
                   
                   
                   
                   
               
               
                 Texin 50D not ann 
                 141 
                 90 
                 100 
                 19 
                 75 
                 19.8 
               
               
                 Texin 50D ann 2 h 
                 141 
                 90 
                 109 
                 37 
                 60 
                 12.1 
               
               
                 Texin 50D ann 20 h 
                 141 
                 90 
                 110 
                 39 
                 50 
                 8.9 
               
               
                 PVC91A 
                 141 
                 90 
                 95 
                 10 
                 41 
                 17.5 
               
               
                 TPE 88A 
                 141 
                 90 
                 106 
                 31 
                 44 
                 9.7 
               
               
                   
               
            
           
         
       
     
     Example 4 
     PVC with shore hardness 91 A, TPE with shore hardness 88 A, and TPU with shore hardness 90 A Ch 14 catheter tubing was packed in three different pack sizes to compare the shape recovery between materials and pack designs. The tubing material was coiled in the pack. The packs were stored for a month at room temperature. Table 6 shows the pack dimensions with different length to width ratios. For this example, L0 was 40 cm and L1 corresponds to the width of the pack. 
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 6 
               
               
                   
                   
               
               
                   
                   
                 Width 
                 Length 
                 Length/width 
               
               
                   
                   
                 [mm] 
                 [mm] 
                 [%] 
               
               
                   
                   
               
             
            
               
                   
                 Pack A 
                 105 
                 140 
                 75 
               
               
                   
                 Pack B 
                 100 
                 150 
                 66 
               
               
                   
                 Pack C 
                  70 
                 160 
                 44 
               
               
                   
                   
               
            
           
         
       
     
       FIGS.  6 - 8    show an illustration of the curvature developed after packing for each of the materials.  FIG.  6    shows the results for Pack A TPU tubing  111 , TPE tubing  311 , and PVC tubing  211 .  FIG.  7    shows the results for Pack A TPU tubing  121 , TPE tubing  221 , and PVC tubing  321 .  FIG.  8    shows the results for Pack A TPU tubing  131 , TPE tubing  331 , and PVC tubing  231 . In all three pack sizes, the TPU material shows better shape recovery than the TPE and PVC material. 
     It will be understood that the embodiments described above are illustrative of some of the applications of the principles of the present subject matter. Numerous modifications may be made by those skilled in the art without departing from the spirit and scope of the claimed subject matter, including those combinations of features that are individually disclosed or claimed herein. For these reasons, the scope hereof is not limited to the above description but is as set forth in the following claims, and it is understood that claims may be directed to the features hereof, including as combinations of features that are individually disclosed or claimed herein.