WO1996022114A9 - An antimicrobial medical device and method - Google Patents
An antimicrobial medical device and methodInfo
- Publication number
- WO1996022114A9 WO1996022114A9 PCT/US1996/000842 US9600842W WO9622114A9 WO 1996022114 A9 WO1996022114 A9 WO 1996022114A9 US 9600842 W US9600842 W US 9600842W WO 9622114 A9 WO9622114 A9 WO 9622114A9
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- triclosan
- medical device
- polymeric material
- polyurethane
- tubing
- Prior art date
Links
- 239000004599 antimicrobial Substances 0.000 title claims abstract description 32
- 230000000845 anti-microbial Effects 0.000 title claims abstract description 12
- XEFQLINVKFYRCS-UHFFFAOYSA-N Triclosan Chemical compound OC1=CC(Cl)=CC=C1OC1=CC=C(Cl)C=C1Cl XEFQLINVKFYRCS-UHFFFAOYSA-N 0.000 claims abstract description 90
- 229960003500 triclosan Drugs 0.000 claims abstract description 89
- 229920002635 polyurethane Polymers 0.000 claims abstract description 30
- 239000004814 polyurethane Substances 0.000 claims abstract description 30
- 239000004014 plasticizer Substances 0.000 claims abstract description 11
- 150000003379 silver compounds Chemical class 0.000 claims abstract description 4
- XNCOSPRUTUOJCJ-UHFFFAOYSA-N diguanide Chemical compound NC(N)=NC(N)=N XNCOSPRUTUOJCJ-UHFFFAOYSA-N 0.000 claims abstract 2
- 239000000463 material Substances 0.000 claims description 35
- 229920005989 resin Polymers 0.000 claims description 9
- 239000011347 resin Substances 0.000 claims description 9
- 244000005700 microbiome Species 0.000 claims description 8
- 239000004721 Polyphenylene oxide Substances 0.000 claims description 7
- 229920000570 polyether Polymers 0.000 claims description 7
- 230000002401 inhibitory effect Effects 0.000 claims description 6
- 238000005192 partition Methods 0.000 claims description 6
- 238000002156 mixing Methods 0.000 claims description 5
- 125000001931 aliphatic group Chemical group 0.000 claims description 4
- 239000012530 fluid Substances 0.000 claims description 3
- 210000001519 tissues Anatomy 0.000 claims description 3
- 230000000813 microbial Effects 0.000 claims description 2
- 229920005749 polyurethane resin Polymers 0.000 claims 2
- 239000003795 chemical substances by application Substances 0.000 abstract description 6
- 239000003814 drug Substances 0.000 description 28
- 229940079593 drugs Drugs 0.000 description 27
- 201000009910 diseases by infectious agent Diseases 0.000 description 17
- 238000011068 load Methods 0.000 description 16
- 229920000642 polymer Polymers 0.000 description 14
- DSUFPYCILZXJFF-UHFFFAOYSA-N 4-[[4-[[4-(pentoxycarbonylamino)cyclohexyl]methyl]cyclohexyl]carbamoyloxy]butyl N-[4-[[4-(butoxycarbonylamino)cyclohexyl]methyl]cyclohexyl]carbamate Chemical compound C1CC(NC(=O)OCCCCC)CCC1CC1CCC(NC(=O)OCCCCOC(=O)NC2CCC(CC3CCC(CC3)NC(=O)OCCCC)CC2)CC1 DSUFPYCILZXJFF-UHFFFAOYSA-N 0.000 description 11
- 239000000203 mixture Substances 0.000 description 11
- 238000001125 extrusion Methods 0.000 description 10
- 239000008188 pellet Substances 0.000 description 8
- 239000007943 implant Substances 0.000 description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- 238000000034 method Methods 0.000 description 6
- JOYRKODLDBILNP-UHFFFAOYSA-N ethyl urethane Chemical compound CCOC(N)=O JOYRKODLDBILNP-UHFFFAOYSA-N 0.000 description 5
- 239000011248 coating agent Substances 0.000 description 4
- 238000000576 coating method Methods 0.000 description 4
- RTZKZFJDLAIYFH-UHFFFAOYSA-N diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 4
- 238000001727 in vivo Methods 0.000 description 4
- 239000004615 ingredient Substances 0.000 description 4
- 241000894006 Bacteria Species 0.000 description 3
- GHXZTYHSJHQHIJ-UHFFFAOYSA-N Exidine Chemical compound C=1C=C(Cl)C=CC=1NC(N)=NC(N)=NCCCCCCN=C(N)N=C(N)NC1=CC=C(Cl)C=C1 GHXZTYHSJHQHIJ-UHFFFAOYSA-N 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000002045 lasting Effects 0.000 description 3
- 239000011159 matrix material Substances 0.000 description 3
- 230000000704 physical effect Effects 0.000 description 3
- 229920001817 Agar Polymers 0.000 description 2
- TZCXTZWJZNENPQ-UHFFFAOYSA-L Barium sulfate Chemical compound [Ba+2].[O-]S([O-])(=O)=O TZCXTZWJZNENPQ-UHFFFAOYSA-L 0.000 description 2
- 210000004369 Blood Anatomy 0.000 description 2
- 229960003260 Chlorhexidine Drugs 0.000 description 2
- 210000003743 Erythrocytes Anatomy 0.000 description 2
- 241000283973 Oryctolagus cuniculus Species 0.000 description 2
- 210000003324 RBC Anatomy 0.000 description 2
- SQGYOTSLMSWVJD-UHFFFAOYSA-N Silver nitrate Chemical compound [Ag+].[O-]N(=O)=O SQGYOTSLMSWVJD-UHFFFAOYSA-N 0.000 description 2
- NDVLTYZPCACLMA-UHFFFAOYSA-N Silver oxide Chemical compound [O-2].[Ag+].[Ag+] NDVLTYZPCACLMA-UHFFFAOYSA-N 0.000 description 2
- 210000003491 Skin Anatomy 0.000 description 2
- 241000295644 Staphylococcaceae Species 0.000 description 2
- 229920002803 Thermoplastic polyurethane Polymers 0.000 description 2
- 235000010419 agar Nutrition 0.000 description 2
- 229940027985 antiseptics and disinfectants Silver compounds Drugs 0.000 description 2
- 244000052616 bacterial pathogens Species 0.000 description 2
- 229940058933 biguanide antimalarials Drugs 0.000 description 2
- 229940090145 biguanide blood glucose lower drugs Drugs 0.000 description 2
- 150000004283 biguanides Chemical class 0.000 description 2
- 238000004166 bioassay Methods 0.000 description 2
- 239000008280 blood Substances 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
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- 238000005191 phase separation Methods 0.000 description 2
- 229920000728 polyester Polymers 0.000 description 2
- 108090000623 proteins and genes Proteins 0.000 description 2
- 102000004169 proteins and genes Human genes 0.000 description 2
- 229940100890 silver compounds Drugs 0.000 description 2
- 244000005714 skin microbiome Species 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 229920001169 thermoplastic Polymers 0.000 description 2
- 230000002588 toxic Effects 0.000 description 2
- 231100000331 toxic Toxicity 0.000 description 2
- 230000002792 vascular Effects 0.000 description 2
- WJLVQTJZDCGNJN-UHFFFAOYSA-N 2-[6-[[amino-[[amino-(4-chloroanilino)methylidene]amino]methylidene]amino]hexyl]-1-[amino-(4-chloroanilino)methylidene]guanidine;hydron;dichloride Chemical compound Cl.Cl.C=1C=C(Cl)C=CC=1NC(N)=NC(N)=NCCCCCCN=C(N)N=C(N)NC1=CC=C(Cl)C=C1 WJLVQTJZDCGNJN-UHFFFAOYSA-N 0.000 description 1
- 229960002152 Chlorhexidine Acetate Drugs 0.000 description 1
- 229960004504 Chlorhexidine Hydrochloride Drugs 0.000 description 1
- 206010064687 Device related infection Diseases 0.000 description 1
- 229940089114 Drug Delivery Device Drugs 0.000 description 1
- 241000233866 Fungi Species 0.000 description 1
- 206010061598 Immunodeficiency Diseases 0.000 description 1
- 241000283977 Oryctolagus Species 0.000 description 1
- 229920001228 Polyisocyanate Polymers 0.000 description 1
- 240000004808 Saccharomyces cerevisiae Species 0.000 description 1
- 206010040047 Sepsis Diseases 0.000 description 1
- 108010082714 Silver Proteins Proteins 0.000 description 1
- CQLFBEKRDQMJLZ-UHFFFAOYSA-M Silver acetate Chemical compound [Ag+].CC([O-])=O CQLFBEKRDQMJLZ-UHFFFAOYSA-M 0.000 description 1
- YSVXTGDPTJIEIX-UHFFFAOYSA-M Silver iodate Chemical compound [Ag+].[O-]I(=O)=O YSVXTGDPTJIEIX-UHFFFAOYSA-M 0.000 description 1
- MSFPLIAKTHOCQP-UHFFFAOYSA-M Silver iodide Chemical compound I[Ag] MSFPLIAKTHOCQP-UHFFFAOYSA-M 0.000 description 1
- UEJSSZHHYBHCEL-UHFFFAOYSA-N Silver sulfadiazine Chemical compound [Ag+].C1=CC(N)=CC=C1S(=O)(=O)[N-]C1=NC=CC=N1 UEJSSZHHYBHCEL-UHFFFAOYSA-N 0.000 description 1
- 239000004433 Thermoplastic polyurethane Substances 0.000 description 1
- 230000001154 acute Effects 0.000 description 1
- 230000003044 adaptive Effects 0.000 description 1
- 238000007792 addition Methods 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 231100000494 adverse effect Toxicity 0.000 description 1
- 239000008272 agar Substances 0.000 description 1
- 125000003118 aryl group Chemical group 0.000 description 1
- 230000003115 biocidal Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000000903 blocking Effects 0.000 description 1
- 239000006161 blood agar Substances 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- LKZMBDSASOBTPN-UHFFFAOYSA-N carbonic acid;silver Chemical compound [Ag].OC(O)=O LKZMBDSASOBTPN-UHFFFAOYSA-N 0.000 description 1
- 238000002512 chemotherapy Methods 0.000 description 1
- YZIYKJHYYHPJIB-UUPCJSQJSA-N chlorhexidine gluconate Chemical compound OC[C@@H](O)[C@@H](O)[C@H](O)[C@@H](O)C(O)=O.OC[C@@H](O)[C@@H](O)[C@H](O)[C@@H](O)C(O)=O.C1=CC(Cl)=CC=C1NC(=N)NC(=N)NCCCCCCNC(=N)NC(=N)NC1=CC=C(Cl)C=C1 YZIYKJHYYHPJIB-UUPCJSQJSA-N 0.000 description 1
- 229960003333 chlorhexidine gluconate Drugs 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000006482 condensation reaction Methods 0.000 description 1
- 230000001143 conditioned Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 239000000599 controlled substance Substances 0.000 description 1
- 239000002537 cosmetic Substances 0.000 description 1
- 230000001472 cytotoxic Effects 0.000 description 1
- 231100000433 cytotoxic Toxicity 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
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- 201000010099 disease Diseases 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
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- 230000029578 entry into host Effects 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- OYQYHJRSHHYEIG-UHFFFAOYSA-N ethyl carbamate;urea Chemical compound NC(N)=O.CCOC(N)=O OYQYHJRSHHYEIG-UHFFFAOYSA-N 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 238000005755 formation reaction Methods 0.000 description 1
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- 239000011521 glass Substances 0.000 description 1
- 230000000004 hemodynamic Effects 0.000 description 1
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- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 238000002513 implantation Methods 0.000 description 1
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- 231100000053 low toxicity Toxicity 0.000 description 1
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- 235000016236 parenteral nutrition Nutrition 0.000 description 1
- 238000005453 pelletization Methods 0.000 description 1
- 239000002953 phosphate buffered saline Substances 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 239000005056 polyisocyanate Substances 0.000 description 1
- 239000002861 polymer material Substances 0.000 description 1
- 239000002952 polymeric resin Substances 0.000 description 1
- 229920005862 polyol Polymers 0.000 description 1
- 150000003077 polyols Chemical class 0.000 description 1
- 229920001296 polysiloxane Polymers 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 231100000812 repeated exposure Toxicity 0.000 description 1
- 230000000979 retarding Effects 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 231100000486 side effect Toxicity 0.000 description 1
- 229940071536 silver acetate Drugs 0.000 description 1
- LKZMBDSASOBTPN-UHFFFAOYSA-L silver carbonate Substances [Ag].[O-]C([O-])=O LKZMBDSASOBTPN-UHFFFAOYSA-L 0.000 description 1
- 229910001958 silver carbonate Inorganic materials 0.000 description 1
- 229940045105 silver iodide Drugs 0.000 description 1
- 229910001961 silver nitrate Inorganic materials 0.000 description 1
- 229910001923 silver oxide Inorganic materials 0.000 description 1
- 229960003600 silver sulfadiazine Drugs 0.000 description 1
- LMEWRZSPCQHBOB-UHFFFAOYSA-M silver;2-hydroxypropanoate Chemical compound [Ag+].CC(O)C([O-])=O LMEWRZSPCQHBOB-UHFFFAOYSA-M 0.000 description 1
- CLDWGXZGFUNWKB-UHFFFAOYSA-M silver;benzoate Chemical compound [Ag+].[O-]C(=O)C1=CC=CC=C1 CLDWGXZGFUNWKB-UHFFFAOYSA-M 0.000 description 1
- MNMYRUHURLPFQW-UHFFFAOYSA-M silver;dodecanoate Chemical compound [Ag+].CCCCCCCCCCCC([O-])=O MNMYRUHURLPFQW-UHFFFAOYSA-M 0.000 description 1
- LTYHQUJGIQUHMS-UHFFFAOYSA-M silver;hexadecanoate Chemical compound [Ag+].CCCCCCCCCCCCCCCC([O-])=O LTYHQUJGIQUHMS-UHFFFAOYSA-M 0.000 description 1
- 238000002791 soaking Methods 0.000 description 1
- 239000000344 soap Substances 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
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- 238000004659 sterilization and disinfection Methods 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
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Definitions
- the present invention relates generally to a medical device, and more particularly to an antimicrobial medical device made from a polymeric material with an antimicrobial drug incorporated within the polymeric matrix, as well as a method for making such a device.
- CVCs central venous catheters
- percutaneous catheters disrupt the body's primary barrier to infection, which is the intact skin surface.
- the wound tract created by catheter placement provides a direct route for the invasion of microorganisms that cause infections. These infections are typically caused by microorganisms colonizing the surface of the skin.
- CNS Coagulase-negative staphylococci
- CNS reside as predominant members of the normal skin flora and possess the ability to adhere to and colonize indwelling medical devices.
- CNS are spherical, gram-positive organisms which cause a variety of diseases in man. Because CNS frequently become drug-resistant, they have risen to a position of special significance in clinical medicine.
- CNS are uniquely adaptive in exploiting the microenvironment of a percutaneous foreign body. Once established, removal of the device is often necessary to resolve the infection caused by these organisms.
- CVCs are percutaneously placed acute catheters that have an estimated duration of about one week.
- the most frequent life-threatening complication from the use of CVCs is septicemia. Even though the use is relatively short term, a CVC- related sepsis rate of 4% is typical. Such infections can prolong hospitalization by an average of 7 days. Unfortunately, CVC-sepsis also has a 10- 20% fatality rate.
- the mean duration is approximately 3 to 4 months.
- infection is a constant threat because the presence of a foreign body will, for a variety of reasons, compromise the normal immune mechanisms of the host against infection.
- an infection may result in the discontinuation of therapy, rehospitalization and possibly additional surgery to remove the implant, not to mention the costs and risks associated therewith. Therefore, prevention of such infections is preferable to treatment, especially when associated with medical devices that are instrumental for patient care.
- Many different approaches have been tried to reduce catheter related infection problems. Since these infections are most often associated with bacteria colonizing the catheter surface and forming a biofilm, many schemes have focused on preventing this from occurring.
- a second approach involves the use of antimicrobial agent delivered from the polymer. This can be done with a compound that diffuses from the device surface.
- Different techniques are available to make a catheter into a controlled drug delivery device.
- the use of a coating containing the drug of interest is well known.
- the advantage of a coating is that it can be applied to a finished device to add the desired antimicrobial feature.
- the drug 2,4,4 '-trichloro-2'-hydroxy diphenyl ether commonly known as triclosan, is a synthetic antimicrobial agent that is commonly used as an adjunct in cosmetics, soaps and dermatological formulations. It also has limited water solubility, about 10-20 ppm.
- Triclosan has a broad antimicrobial spectrum at low concentration and, is active against both gram-positive and gram-negative bacteria, yeast and other fungi. Also, this agent demonstrates a low toxicity and superior activity against CNS.
- an antimicrobial agent in the polymeric material used to make medical devices.
- Another object of the present invention is to provide an antimicrobial medical device that releases an antimicrobial agent in a controlled manner to provide biocidal properties that are safe and long lasting.
- the present invention is directed to a medical device made of a polymeric material that combines polyurethane and an antimicrobial agent, or combination of agents, that acts as a plasticizer in *che formation of the polymeric material.
- the antimicrobial agent is held in the polymeric matrices, so that migration is inhibited, causing the controlled release of the agent.
- the present invention also provides a method of making the antimicrobial medical device wherein an antimicrobial agent is incorporated into the device by blending the agent into the polymer resin before or during extrusion.
- the preferred antimicrobial agent is triclosan, which is particularly effective against staphylococci. Combinations of triclosan with biguanides or silver compounds can also be used in the present device. In polyurethane, triclosan will provide long lasting protection against colonization by a broad spectrum of microbes.
- Triclosan has unexpected physical properties that render it soluble and completely miscible in polyurethane so that it acts as a plasticizer. As a result, the triclosan can have a high loading in the polyurethane without causing a phase separation. Depending on the specific polymer, the triclosan may obviate the need to use a separate plasticizer in the polymeric material. The triclosan will soften the polymer for processing and provide a degree of elasticity in the formed device. Triclosan is effective at killing certain skin flora, which is the source of infection for most percutaneous and indwelling medical devices.
- the biguanides that may be used in the present invention in combination with the triclosan include chlorhexidine acetate, chlorhexidine gluconate, chlorhexidine hydrochloride and chlorhexidine sulfate, as well as other salts of chlorhexidine.
- the silver compounds that may be used in the present invention in combination with the triclosan include silver acetate, silver benzoate, silver carbonate, silver iodate, silver iodide, silver lactate, silver laurate, silver nitrate, silver oxide, silver palmitate, silver protein, and silver sulfadiazine.
- the medical devices made according to the present invention include catheters, stents, shunts, drainage tubes and other percutaneous devices.
- the term "safe and effective amount” means an amount of antimicrobial agent and/or mixture thereof which is capable of retarding or preventing microbial colonization and adherence to the surface of the polymeric materials used herein while causing minimum undesirable side effects when in contact with living tissue.
- the amount delivered is above the minimum inhibitory concentration of the targeted microorganisms.
- Figure 1 is a graph of the serial zone transfer data for extruded blended tubing of the present invention and 5% swell loaded tubing.
- Figure 2 is a graph of the serial zone transfer data for the explanted samples tubing used in the in-vivo studies.
- Figure 3 is a graph of the assay data for the explanted tubing samples used in the in-vivo studies.
- the simplest method of incorporating the antimicrobial agent, triclosan is by direct compounding of the drug into the urethane resin before extrusion. It is a low cost process and the resulting drug reservoir is large. This can be done only because the drug is compatible with the polymeric material.
- polyurethane is easily shaped into three-dimensional structures. Once molded, the formed antimicrobial products are dimensionally stable even after repeated exposure to boiling water and moderately high temperatures.
- polyurethane means a thermoplastic polymer produced by the condensation reaction of a polyisocyanate and a hydroxyl-containing material, including ether-based polyurethane, ester-based polyurethane, poly(ether urethane urea) , silicone urethane, in particular, aliphatic or aromatic diisocyanates used in various combinations with polyether, aliphatic or aromatic polyester soft segments to make the thermoplastic polyurethane.
- Soft segments include high molecular weight polyols with glass transition temperatures typically below room temperature.
- the preferred polyurethanes have soft segment compositions that are polyether-based or are highly aliphatic. Less preferred polyurethanes are those with polyester soft segments.
- the polyurethane must be biocompatible, elastomeric and processable, as well as be able to solubilize triclosan.
- the polymeric material acts as a reservoir for the triclosan and uniform distribution acts to optimize the loading.
- triclosan can be incorporated in amounts up to 30% by weight in Tecoflex 80A with no phase separation problems.
- Tecoflex is a registered trademark of Thermedics, Inc.
- Tecoflex 80A is an 80 Shore A duro eter thermoplastic polyether urethane manufactured using an aliphatic diisocyanate and polyether soft segment.
- the triclosan acts as a plasticizer.
- plasticizers are used in processing polymer materials to soften and improve flow during extrusion without causing any significant loss in other physical properties, such as stiffness, elongation set, etc.
- Plasticizer can also be used to lower the durometer of a polymeric device.
- the typical plasticizer will leach out slowly and can be toxic. The present use of triclosan alleviates this concern.
- the preferred loading of triclosan is in the range of 0.5 to 15.0 percent by weight.
- the more preferred loading of triclosan is in the range of 1.0 to 10.0 percent by weight.
- the most preferred loading of triclosan is in the range of 5.0 to 10.0 percent.
- the ultimate loading to attain the required physical properties is dependent, in part, on the durometer of the polymer used.
- the loading of the triclosan in the present invention can be obtained for durometer values from 75 Shore A to 60 Shore D. For a given softness of the drug loaded polymer, the triclosan loading is higher for polyurethanes of greater durometer.
- Extrusion requires that the antimicrobial agent have good thermal stability, which is satisfied by triclosan since it exhibits no significant decomposition below 280-290°C. Triclosan has a measurable vapor pressure at higher temperatures. According to the method of the present invention, extrusion of Tecoflex EG-80A resin is typically carried out at about 160-175°C.
- the drug delivery characteristics of triclosan from polyurethane are well suited for antimicrobial devices.
- Triclosan is very soluble in urethane and can diffuse through the polymeric material.
- the triclosan is incorporated into the polymeric matrix and is released when the device is used.
- the concentration of drug immediately adjacent to the device depends on the initial concentration of the triclosan, the partition coefficient between the polymer and water, the diffusivity of the triclosan in the urethane, and the rate the drug is swept away from the device.
- 5% triclosan loading in 80A polyurethane has a partition coefficient of less than lxlO" 4 .
- the drug delivery rate is also limited by the very low solubility of triclosan in water and its very low partition coefficient between water and polyurethane. These factors prevent the drug from reaching a saturated concentration that is, for example, cytotoxic to red blood cells. In measurements taken in a phosphate buffered saline solution, triclosan has saturation concentration of 16 ppm, which is safe and not toxic to red blood cells.
- the delivery rate is such that the concentration of the drug at the polymer surface is above the minimum inhibitory concentration (MIC) of the targeted microbes so as to be effective.
- the medical devices of the present invention have the resulting advantageous property of a long duration of activity.
- the resin pellets can be "tumble coated" with triclosan; the resin pellets can be compounded with triclosan using a twin screw compounder; the starting ingredients can be pelletized together using a twin screw machine; and the resin pellets can be compounded with the triclosan using an extruder/compounder machine.
- Compounding the triclosan and extruding in a single process step is preferred, because the resulting material will have a higher durometer.
- the resin pellets, triclosan and other ingredients can also be fed into the compounder at a suitable rate.
- the ingredients are melted, blended and then extruded into strands.
- the strands may be pelletized and dried prior to further processing.
- the homogeneous pellets of polymer and triclosan, prepared as described above, may be remelted and molded or extruded into the desired shape of the medical device.
- Tecoflex Blue (293) single lumen 0.110 x 0.065 5% triclosan EG-80A-B20 2. Tecoflex Blue (293) single lumen 0.110 x 0.065 0% triclosan EG-80A-B20 (control) 3. Tecoflex Blue (293) single lumen 0.110 x. 0.065 5% triclosan EG-85A-B20 4. Tecoflex Blue (293) single lumen 0.110 x. 0.065 0% triclosan EG-85A B20 (control)
- the resins used were 20% by weight of barium sulphate for radiopacity.
- the triclosan was blended directly into the Tecoflex resin, which was repelletized by a water pelletizer and extruded to form the tubing.
- the extrusion was performed without any difficulties.
- the plasticizer effect of the triclosan permitted the extrusion to be performed at lower temperatures, which may offer a manufacturing advantage.
- the physical characteristics of tubing made by the present invention were compared with the control tubing made with triclosan and similar commercially available tubing. For example, the surface of the extruded tubing of the present invention was inspected under an optical microscope. It was found that both the exterior and intraluminal surfaces of the tubing of the present invention were smoother than the control samples and commercially available samples of 9 Fr.
- tubing from Strato Medical. At room temperature, the drug loaded formulations were not sticky and exhibited no blocking behavior. At 40°C, the 80A tubing with drug was softer but did not block. At 60°C, the 85A tubing blocked slightly, but the lumen would spring back open. However, at 60°C, the 80A tubing tended to stay closed when squeezed.
- Figure 1 contains the data from the serial zone transfer tests, which are plotted as size of the zone versus time. It was discovered that the 85A tubing and the 5% swell loaded tubing had the same zone behavior during the 5 day test period. Zone size is only moderately sensitive to the drug delivery rate.
- Triclosan that was swell loaded into polyurethane tubing was used for feasibility in-vivo studies, as described below.
- the zone tests conducted on swell loaded polyurethane tubing showed results that were similar to using the blended ingredients.
- swell loading is a simple technique which involves soaking the polyurethane article in a solution containing the triclosan, drying it, and then performing a quick rinse. Swell loading, however, yields a non-uniform drug distribution.
- a major drawback of swell loading is that some polymer is extracted and other additives, such as extrusion lubricants and stabilizers, can be leached out as well.
- the direct blending of the triclosan in the present invention does not have these disadvantages.
- tube samples with nominal values of "5%” and ,, 10%" of triclosan were prepared by swell loading.
- the 5% swell loaded tubing contained in the range of 5.5 to 6.1% triclosan, by weight, and the 10% swell loaded tubing contained about 13.9% triclosan, by weight.
- the swell loaded tubing was cut into 2 cm segments and sterilized. The lumen of the tube sections were left open. Control sets of tubing with no drug were also prepared.
- the tube samples were implanted intramuscularly in the backs of white New Zealand rabbits. For each point in time when explants were to be taken, samples of six tube segments for each type of loaded tubing and two control tubing were prepared and implanted. Explants were taken at 30, 60 and 90 days. Upon retrieval, the implant sites were examined macroscopically and all samples were scored as benign. Further histopathology tests on the implant sites confirmed these initial observations. While rabbit implant studies were not designed to measure long term biostability of materials, nevertheless, the samples tested showed only minor differences between the drug and non-drug loaded samples.
- Zone of inhibition assays were performed using the recovered explanted samples as well.
- Figure 2 shows the data plotted as zone size versus time.
- the test organism was Staph. epidermidis in two different types of agar, i.e., MH and blood agars. After 90 days, both the 10% and 5% samples were still active. As clearly shown in Figure 2, the 10% drug samples give bigger zones than the 5% samples.
- the results showed that the delivery of the triclosan was not controlled only by the aqueous solubility, since the 10% and 5% samples did not have the same size zones, but may also be controlled by the diffusion rate in the polymeric material. Distribution of the triclosan in the polymeric material will also be a factor in the delivery rate.
- the triclosan content of the explanted samples were assayed by dissolving the polymer in solvent and measuring the triclosan concentration by UV-vis spectrophotometry.
- the drug concentrations from the explanted samples are listed in Table 3 below.
- plotting the above data shows an exponential decay.
- the above tests show that the extruded blended tubing can be expected to perform as intended and to be effective over an extended period of time.
- Triclosan present in an amount of about 5%, by weight, will be effective for about 45 days against a microorganism with an MIC of about 1 ppm.
- the medical devices made from polyurethanes and triclosan in the present invention will provide long lasting protection against infection.
- the triclosan will be delivered in an amount that is above the minimum inhibitory concentration of the targeted microorganisms, including CNS, to prevent colonization of the device surface.
Abstract
The invention relates to an antimicrobial device made using polyurethane and antimicrobial agent, triclosan or a combination of triclosan with a biguanide or silver compound, that provides for a controlled release of the agent. The triclosan has the property of acting as a plasticizer in the polyurethane and being soluble therein.
Description
AN ANTIMICROBIAL MEDICAL DEVICE AND METHOD
BACKGROUND OF THE INVENTION
The present invention relates generally to a medical device, and more particularly to an antimicrobial medical device made from a polymeric material with an antimicrobial drug incorporated within the polymeric matrix, as well as a method for making such a device.
Many medical devices are made from polymeric materials due to their mechanical properties and/or biocompatibility. Examples of such medical devices include CSF shunts, vascular grafts, endotracheal tubes, peritoneal and he odialysis tubes, Foley catheters, and percutaneous catheters of all types. However, a major medical complication associated with the use of indwelling medical devices is infection. For catheters, the infection problem is well documented because catheters are so commonly used. Of the over 40 million patients hospitalized each year, over one-half will have a catheter used as part of their medical procedure. Percutaneously and surgically inserted central venous catheters (CVCs) are used for the administration of fluids, drugs, total parenteral nutrition, and for hemodynamic monitoring. The use of percutaneous catheters disrupt the body's primary barrier to infection, which is the intact skin surface. The wound tract created by catheter placement provides a direct route
for the invasion of microorganisms that cause infections. These infections are typically caused by microorganisms colonizing the surface of the skin.
Coagulase-negative staphylococci (CNS) is the most common cause of vascular access infections. CNS reside as predominant members of the normal skin flora and possess the ability to adhere to and colonize indwelling medical devices. CNS are spherical, gram-positive organisms which cause a variety of diseases in man. Because CNS frequently become drug-resistant, they have risen to a position of special significance in clinical medicine. CNS are uniquely adaptive in exploiting the microenvironment of a percutaneous foreign body. Once established, removal of the device is often necessary to resolve the infection caused by these organisms.
Most CVCs are percutaneously placed acute catheters that have an estimated duration of about one week. The most frequent life-threatening complication from the use of CVCs is septicemia. Even though the use is relatively short term, a CVC- related sepsis rate of 4% is typical. Such infections can prolong hospitalization by an average of 7 days. Unfortunately, CVC-sepsis also has a 10- 20% fatality rate.
In the case of a surgically implanted Hickman-type catheter, the mean duration is approximately 3 to 4 months. As a result, infection is a constant threat because the presence of a foreign body will, for a variety of reasons, compromise the normal immune mechanisms of the host against infection. For an immunocompromised patient, especially those on chemotherapy, an infection may result in the discontinuation of therapy, rehospitalization and possibly additional surgery to remove the implant, not to mention the costs and
risks associated therewith. Therefore, prevention of such infections is preferable to treatment, especially when associated with medical devices that are instrumental for patient care. Many different approaches have been tried to reduce catheter related infection problems. Since these infections are most often associated with bacteria colonizing the catheter surface and forming a biofilm, many schemes have focused on preventing this from occurring. One approach is to reduce the adherence of bacteria to the catheter surface by changing its surface properties. Coating with hydrogels to make the surface more hydrophilic is effective for short periods. However, the main drawback to this approach is that the surfaces of the intravascular device will become conditioned by proteins in the blood, and many microorganisms have the ability to adhere to polymers and proteins. A second approach involves the use of antimicrobial agent delivered from the polymer. This can be done with a compound that diffuses from the device surface. Different techniques are available to make a catheter into a controlled drug delivery device. The use of a coating containing the drug of interest is well known. The advantage of a coating is that it can be applied to a finished device to add the desired antimicrobial feature. However, there are disadvantages, including limitations in the size of the drug reservoir. There is a practical upper limit of about 100 microns on the coating thickness that can be easily applied. Many commercially available devices have coatings that are only 10 microns thick.
Due to the propensity of CNS to colonize the surfaces of medical devices, any strategy to prevent infection by incorporating an antimicrobial agent into polymers must first address the efficacy against
CNS. The drug 2,4,4 '-trichloro-2'-hydroxy diphenyl ether, commonly known as triclosan, is a synthetic antimicrobial agent that is commonly used as an adjunct in cosmetics, soaps and dermatological formulations. It also has limited water solubility, about 10-20 ppm.
Triclosan has a broad antimicrobial spectrum at low concentration and, is active against both gram-positive and gram-negative bacteria, yeast and other fungi. Also, this agent demonstrates a low toxicity and superior activity against CNS.
The approach taken herein is to incorporate an antimicrobial agent in the polymeric material used to make medical devices. However, it is often difficult to obtain the necessary physical characteristics in the polymeric material when combining the antimicrobial agent and the polymer. It is, therefore, an object of the present invention to provide an antimicrobial medical device that incorporates an antimicrobial agent, or combination of agents, to prevent infections.
Another object of the present invention is to provide an antimicrobial medical device that releases an antimicrobial agent in a controlled manner to provide biocidal properties that are safe and long lasting.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
SUMMARY OF THE INVENTION
The present invention is directed to a medical device made of a polymeric material that combines polyurethane and an antimicrobial agent, or combination of agents, that acts as a plasticizer in
*che formation of the polymeric material. The antimicrobial agent is held in the polymeric matrices, so that migration is inhibited, causing the controlled release of the agent. The present invention also provides a method of making the antimicrobial medical device wherein an antimicrobial agent is incorporated into the device by blending the agent into the polymer resin before or during extrusion. The preferred antimicrobial agent is triclosan, which is particularly effective against staphylococci. Combinations of triclosan with biguanides or silver compounds can also be used in the present device. In polyurethane, triclosan will provide long lasting protection against colonization by a broad spectrum of microbes.
The controlled delivery of the antimicrobial agent from the polymeric material is apparently achieved by incorporating the triclosan in the polymeric matrices. Triclosan has unexpected physical properties that render it soluble and completely miscible in polyurethane so that it acts as a plasticizer. As a result, the triclosan can have a high loading in the polyurethane without causing a phase separation. Depending on the specific polymer, the triclosan may obviate the need to use a separate plasticizer in the polymeric material. The triclosan will soften the polymer for processing and provide a degree of elasticity in the formed device. Triclosan is effective at killing certain skin flora, which is the source of infection for most percutaneous and indwelling medical devices.
The biguanides that may be used in the present invention in combination with the triclosan include chlorhexidine acetate, chlorhexidine gluconate, chlorhexidine hydrochloride and
chlorhexidine sulfate, as well as other salts of chlorhexidine. The silver compounds that may be used in the present invention in combination with the triclosan include silver acetate, silver benzoate, silver carbonate, silver iodate, silver iodide, silver lactate, silver laurate, silver nitrate, silver oxide, silver palmitate, silver protein, and silver sulfadiazine.
The medical devices made according to the present invention include catheters, stents, shunts, drainage tubes and other percutaneous devices.
According to the present invention, the term "safe and effective amount" means an amount of antimicrobial agent and/or mixture thereof which is capable of retarding or preventing microbial colonization and adherence to the surface of the polymeric materials used herein while causing minimum undesirable side effects when in contact with living tissue. The amount delivered is above the minimum inhibitory concentration of the targeted microorganisms.
BRIEF DESCRIPTION OF THE DRAWING
Figure 1 is a graph of the serial zone transfer data for extruded blended tubing of the present invention and 5% swell loaded tubing. Figure 2 is a graph of the serial zone transfer data for the explanted samples tubing used in the in-vivo studies.
Figure 3 is a graph of the assay data for the explanted tubing samples used in the in-vivo studies.
DETAILED DESCRIPTION OF THE INVENTION
According to the invention, the simplest method of incorporating the antimicrobial agent, triclosan, is by direct compounding of the drug into the urethane resin before extrusion. It is a low
cost process and the resulting drug reservoir is large. This can be done only because the drug is compatible with the polymeric material. In addition, polyurethane is easily shaped into three-dimensional structures. Once molded, the formed antimicrobial products are dimensionally stable even after repeated exposure to boiling water and moderately high temperatures.
According to the invention, the term "polyurethane" means a thermoplastic polymer produced by the condensation reaction of a polyisocyanate and a hydroxyl-containing material, including ether-based polyurethane, ester-based polyurethane, poly(ether urethane urea) , silicone urethane, in particular, aliphatic or aromatic diisocyanates used in various combinations with polyether, aliphatic or aromatic polyester soft segments to make the thermoplastic polyurethane. Soft segments include high molecular weight polyols with glass transition temperatures typically below room temperature. The preferred polyurethanes have soft segment compositions that are polyether-based or are highly aliphatic. Less preferred polyurethanes are those with polyester soft segments. The polyurethane must be biocompatible, elastomeric and processable, as well as be able to solubilize triclosan. The polymeric material acts as a reservoir for the triclosan and uniform distribution acts to optimize the loading. For example, triclosan can be incorporated in amounts up to 30% by weight in Tecoflex 80A with no phase separation problems. Tecoflex is a registered trademark of Thermedics, Inc. Tecoflex 80A is an 80 Shore A duro eter thermoplastic polyether urethane manufactured using an aliphatic diisocyanate and polyether soft segment.
In the polyurethanes of the present invention, the triclosan acts as a plasticizer. Generally, plasticizers are used in processing polymer materials to soften and improve flow during extrusion without causing any significant loss in other physical properties, such as stiffness, elongation set, etc. Plasticizer can also be used to lower the durometer of a polymeric device. However, the typical plasticizer will leach out slowly and can be toxic. The present use of triclosan alleviates this concern.
At over 30% triclosan loading, the polymeric material becomes soft, sticky and unacceptable for forming the medical devices of the present invention. The preferred loading of triclosan is in the range of 0.5 to 15.0 percent by weight. The more preferred loading of triclosan is in the range of 1.0 to 10.0 percent by weight. The most preferred loading of triclosan is in the range of 5.0 to 10.0 percent. The ultimate loading to attain the required physical properties is dependent, in part, on the durometer of the polymer used. The loading of the triclosan in the present invention can be obtained for durometer values from 75 Shore A to 60 Shore D. For a given softness of the drug loaded polymer, the triclosan loading is higher for polyurethanes of greater durometer.
Extrusion requires that the antimicrobial agent have good thermal stability, which is satisfied by triclosan since it exhibits no significant decomposition below 280-290°C. Triclosan has a measurable vapor pressure at higher temperatures. According to the method of the present invention, extrusion of Tecoflex EG-80A resin is typically carried out at about 160-175°C.
As shown by the present invention, due to its chemical properties, the drug delivery
characteristics of triclosan from polyurethane are well suited for antimicrobial devices. Triclosan is very soluble in urethane and can diffuse through the polymeric material. The triclosan is incorporated into the polymeric matrix and is released when the device is used. When a medical device of the present invention is first inserted into the body, the concentration of drug immediately adjacent to the device depends on the initial concentration of the triclosan, the partition coefficient between the polymer and water, the diffusivity of the triclosan in the urethane, and the rate the drug is swept away from the device.
As used herein, the partition coefficient can be set forth by the following equation: wt.% drug in water partition coefficient = __*. - J_„„ •„ polyurethane **'* dru<? ιn As shown by the present invention, 5% triclosan loading in 80A polyurethane has a partition coefficient of less than lxlO"4.
In addition to the rate of diffusion, the drug delivery rate is also limited by the very low solubility of triclosan in water and its very low partition coefficient between water and polyurethane. These factors prevent the drug from reaching a saturated concentration that is, for example, cytotoxic to red blood cells. In measurements taken in a phosphate buffered saline solution, triclosan has saturation concentration of 16 ppm, which is safe and not toxic to red blood cells. However, the delivery rate is such that the concentration of the drug at the polymer surface is above the minimum inhibitory concentration (MIC) of the targeted microbes so as to be effective. The medical devices of the present invention have the resulting advantageous property of a long duration of activity.
There are several alternative methods that can be used for incorporating the antimicrobial agent into the polymeric material. For example, the resin pellets can be "tumble coated" with triclosan; the resin pellets can be compounded with triclosan using a twin screw compounder; the starting ingredients can be pelletized together using a twin screw machine; and the resin pellets can be compounded with the triclosan using an extruder/compounder machine. Compounding the triclosan and extruding in a single process step is preferred, because the resulting material will have a higher durometer. These methods of compounding the antimicrobial agent into the resin result in the triclosan being uniformly distributed and incorporated into the polymeric matrix.
When using the twin screw compounder, the resin pellets, triclosan and other ingredients, such as fillers and pigments, can also be fed into the compounder at a suitable rate. In the compounder, the ingredients are melted, blended and then extruded into strands. The strands may be pelletized and dried prior to further processing. The homogeneous pellets of polymer and triclosan, prepared as described above, may be remelted and molded or extruded into the desired shape of the medical device.
EXAMPLE Polyurethane tubing was fabricated with triclosan incorporated directly into the polymer using a loading of triclosan of 5.2 ± .4% by weight. Table 1 shows the tubing samples that were produced. The formulation for the tubing was generally the same as for the Tecoflex products available from Strato Medical, except for the addition of the antimicrobial agent. Also, tubing without the triclosan was made for use in tests as a control.
Table 1. Polyurethane Tubing with Triclosan
1. Tecoflex Blue (293) single lumen 0.110 x 0.065 5% triclosan EG-80A-B20 2. Tecoflex Blue (293) single lumen 0.110 x 0.065 0% triclosan EG-80A-B20 (control) 3. Tecoflex Blue (293) single lumen 0.110 x. 0.065 5% triclosan EG-85A-B20 4. Tecoflex Blue (293) single lumen 0.110 x. 0.065 0% triclosan EG-85A B20 (control)
All the resins used were 20% by weight of barium sulphate for radiopacity. The triclosan was blended directly into the Tecoflex resin, which was repelletized by a water pelletizer and extruded to form the tubing. The extrusion was performed without any difficulties. The plasticizer effect of the triclosan permitted the extrusion to be performed at lower temperatures, which may offer a manufacturing advantage. The physical characteristics of tubing made by the present invention were compared with the control tubing made with triclosan and similar commercially available tubing. For example, the surface of the extruded tubing of the present invention was inspected under an optical microscope. It was found that both the exterior and intraluminal surfaces of the tubing of the present invention were smoother than the control samples and commercially available samples of 9 Fr. tubing from Strato Medical. At room temperature, the drug loaded formulations were not sticky and exhibited no blocking behavior. At 40°C, the 80A tubing with drug was softer but did not block. At 60°C, the 85A tubing blocked slightly, but the lumen would spring back open. However, at 60°C, the 80A tubing tended to stay closed when squeezed.
Both the tubing and the compounded pellets used to produce the tubing were assayed for triclosan
content by the UV-vis method. From the results presented in Table 2, it appears that little, if any, triclosan was lost due to the pelletizing and extrusion processes. Table 2
Sample % Triclosan (w/w)
EG-80A-B20 pellets + triclosan 5.1 ± 0.1
EG-85A-B20 pellets + triclosan 5.4 ± 0.2
EG-80A-B20 tubing + triclosan 4.9 ± 0.03 EG-85A-B20 tubing + triclosan 5.1 ± 0.1
Serial zone transfer tests were performed with the extruded 80A and 85A tubing. These test results were compared with some tests for "5%" solvent swell loaded tubing, which was prepared as described below. The zone tests are used to measure a "zone of inhibition," which means a region containing a sufficient concentration of antimicrobial agents that growth and reproduction of microorganisms within the zone are halted. The test organism was Staph. epidermidis and blood agar was the media. The test data showed that there was sustained delivery of the triclosan over several days.
Figure 1 contains the data from the serial zone transfer tests, which are plotted as size of the zone versus time. It was discovered that the 85A tubing and the 5% swell loaded tubing had the same zone behavior during the 5 day test period. Zone size is only moderately sensitive to the drug delivery rate.
Rabbit Implantation In-Vivo Studies:
Triclosan that was swell loaded into polyurethane tubing was used for feasibility in-vivo studies, as described below. The zone tests conducted on swell loaded polyurethane tubing showed results that were similar to using the blended ingredients.
Used as a method for mimicking the blending by or before extrusion of the present invention, swell loading is a simple technique which involves soaking the polyurethane article in a solution containing the triclosan, drying it, and then performing a quick rinse. Swell loading, however, yields a non-uniform drug distribution. In addition, a major drawback of swell loading is that some polymer is extracted and other additives, such as extrusion lubricants and stabilizers, can be leached out as well. The direct blending of the triclosan in the present invention does not have these disadvantages.
For these studies, tube samples with nominal values of "5%" and ,,10%" of triclosan were prepared by swell loading. The 5% swell loaded tubing contained in the range of 5.5 to 6.1% triclosan, by weight, and the 10% swell loaded tubing contained about 13.9% triclosan, by weight.
The swell loaded tubing was cut into 2 cm segments and sterilized. The lumen of the tube sections were left open. Control sets of tubing with no drug were also prepared. The tube samples were implanted intramuscularly in the backs of white New Zealand rabbits. For each point in time when explants were to be taken, samples of six tube segments for each type of loaded tubing and two control tubing were prepared and implanted. Explants were taken at 30, 60 and 90 days.
Upon retrieval, the implant sites were examined macroscopically and all samples were scored as benign. Further histopathology tests on the implant sites confirmed these initial observations. While rabbit implant studies were not designed to measure long term biostability of materials, nevertheless, the samples tested showed only minor differences between the drug and non-drug loaded samples. The time zero and 90 day explants were inspected and examined under the microscope for surface changes. Prior to implant, after swell loading and sterilization, all sample surfaces appeared fairly glossy. The drug loaded 90 day implants had a dull surface with no gloss. The surface of the control 90 day implant still had some gloss. Photomicrographs were taken at 200 or 500 magnification in reflectance mode with crossed polarizers. All the samples showed a surface with some striations and tiny knobby features. There is no chemical reason why triclosan would have any adverse effect on a polyether urethane. In addition, by way of comparison, the biostability of the Tecoflex material has been studied extensively and has been shown to be acceptable for a wide range of applications.
Zone of inhibition assays were performed using the recovered explanted samples as well. Figure 2 shows the data plotted as zone size versus time. The test organism was Staph. epidermidis in two different types of agar, i.e., MH and blood agars. After 90 days, both the 10% and 5% samples were still active. As clearly shown in Figure 2, the 10% drug samples give bigger zones than the 5% samples. The results showed that the delivery of the triclosan was not controlled only by the aqueous solubility, since the 10% and 5% samples did not have the same size zones, but may also be controlled by
the diffusion rate in the polymeric material. Distribution of the triclosan in the polymeric material will also be a factor in the delivery rate. In addition, the triclosan content of the explanted samples were assayed by dissolving the polymer in solvent and measuring the triclosan concentration by UV-vis spectrophotometry. The drug concentrations from the explanted samples are listed in Table 3 below.
Table 3
Drug Totals on Explanted Tubing Samples Percent Drug by Weight
Sample Days 0 30 60
90
"5%" Tubing 6.1 2.8 0.75 0.19
"10%" Tubing 13.9 5.5 1.62
0.61
As shown in Figure 3, plotting the above data shows an exponential decay. The above tests show that the extruded blended tubing can be expected to perform as intended and to be effective over an extended period of time. Triclosan present in an amount of about 5%, by weight, will be effective for about 45 days against a microorganism with an MIC of about 1 ppm.
The medical devices made from polyurethanes and triclosan in the present invention will provide long lasting protection against infection. The triclosan will be delivered in an amount that is above the minimum inhibitory concentration of the
targeted microorganisms, including CNS, to prevent colonization of the device surface.
Finally, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modification and equivalents may fall within the scope of the invention.
Claims
1. A medical device comprising a polymeric material containing polyurethane; and an antimicrobial agent that acts as a plasticizer in said polymeric material and is soluble in said polyurethane, wherein said antimicrobial agent is homogeneously incorporated into said polymeric material and is released from said polymeric material in the presence of biological tissue or fluid in an effective amount to prevent microbial colonization on surfaces of said medical device and in the tissue or fluid surrounding said surfaces.
2. The medical device according to Claim l wherein said antimicrobial agent comprises triclosan.
3. The medical device according to Claim 1 wherein said antimicrobial agent comprises triclosan and a biguanide or silver compound.
4. The medical device according to Claim 2 wherein said polymeric material has a durometer value in the range of 75 Shore A to 60 Shore D.
5. The medical device according to Claim 4 wherein said triclosan is present in an amount of up to 30 percent by weight of said polymeric material.
6. The medical device according to Claim 2 wherein said triclosan is present in an amount in the range of 0.5 to 15 percent by weight of said polymeric material.
7. The medical device according to Claim 6 wherein said triclosan is present in an amount of about 5 percent by weight and is effective for about 45 days against a microorganism with a minimum inhibitory concentration of about 1 ppm.
8. The medical device according to Claim 7 wherein said triclosan has a partition coefficient of less than lxlO"4.
9. The medical device according to Claim 6 wherein said triclosan is present in an amount in the range of 5.0 to 10 percent by weight of said polymeric material.
10. The medical device according to Claim 1 wherein said polyurethane comprises an aliphatic diisocyanate and polyether soft segments.
11. The medical device according to Claim 1 where said polyurethane comprises an aromatic diisocyanate and aliphatic soft segments.
12. The medical device according to Claim 1 wherein said polymeric material is formed into a catheter.
13. The medical device according to Claim 1 wherein said polymeric material is formed into a drainage tube.
14. The medical device according to Claim 1 wherein said polymeric material is formed into a stent.
15. The medical device according to Claim 1 wherein said polymeric material is formed into a shunt.
16. A method for making an antimicrobial medical device comprising blending a polyurethane resin and up to 30 percent of triclosan, by weight, to form a polymeric material, whereby said triclosan is releasably incorporated into said polymeric material; and said triclosan being solubilized in said polyurethane as a plasticizer.
17. The method according to Claim 16 wherein said blending comprises extruding said resin and triclosan to make said medical device.
18. The method according to Claim 16 wherein said polyurethane resin is polyether-based.
19. The method according to Claim 16 wherein said polymeric material has a durometer value in the range of 75 Shore A to 60 Shore D.
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
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JP8522425A JPH11500330A (en) | 1995-01-18 | 1996-01-18 | Antimicrobial medical device and method |
AU47636/96A AU4763696A (en) | 1995-01-18 | 1996-01-18 | An antimicrobial medical device and method |
EP96903614A EP0804256A1 (en) | 1995-01-18 | 1996-01-18 | An antimicrobial medical device and method |
Applications Claiming Priority (2)
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US37429095A | 1995-01-18 | 1995-01-18 | |
US08/374,290 | 1995-01-18 |
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WO1996022114A1 WO1996022114A1 (en) | 1996-07-25 |
WO1996022114A9 true WO1996022114A9 (en) | 1996-10-03 |
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PCT/US1996/000842 WO1996022114A1 (en) | 1995-01-18 | 1996-01-18 | An antimicrobial medical device and method |
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EP (1) | EP0804256A1 (en) |
JP (1) | JPH11500330A (en) |
AU (1) | AU4763696A (en) |
CA (1) | CA2210119A1 (en) |
WO (1) | WO1996022114A1 (en) |
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US5772640A (en) | 1996-01-05 | 1998-06-30 | The Trustees Of Columbia University Of The City Of New York | Triclosan-containing medical devices |
AUPN596595A0 (en) * | 1995-10-13 | 1995-11-09 | Priscott, Paul Kenneth | Improvements in polymeric materials for use in medical applications |
AU712132B2 (en) * | 1995-10-13 | 1999-10-28 | Paul Kenneth Priscott | Improvements in implantable medical devices |
DE19812160C1 (en) * | 1998-03-20 | 1999-07-08 | Bayer Ag | Polyurethane articles containing antibiotic |
GB9810565D0 (en) * | 1998-05-18 | 1998-07-15 | Valpar Ind Ltd | Antimicrobial Plastic tubing |
US6238575B1 (en) * | 1998-07-29 | 2001-05-29 | Microban Products Company | Antimicrobial treatment of enclosed systems having continuous or intermittent fluid flow |
JP2002529587A (en) | 1998-11-12 | 2002-09-10 | バイエル アクチェンゲゼルシャフト | Active ingredient-containing polyether block amide |
DE19852192C2 (en) * | 1998-11-12 | 2003-04-24 | Bayer Ag | Aromatic copolyesters containing active ingredient |
BR0009139A (en) * | 1999-01-28 | 2001-11-27 | Union Carbide Chem Plastic | Playful medical devices |
US6224579B1 (en) * | 1999-03-31 | 2001-05-01 | The Trustees Of Columbia University In The City Of New York | Triclosan and silver compound containing medical devices |
EP1190622B1 (en) | 2000-09-21 | 2006-06-07 | Ciba SC Holding AG | Mixtures of phenolic and inorganic materials with antimicrobial activity |
US7329412B2 (en) | 2000-12-22 | 2008-02-12 | The Trustees Of Columbia University In The City Of New York | Antimicrobial medical devices containing chlorhexidine free base and salt |
US7993390B2 (en) | 2002-02-08 | 2011-08-09 | Boston Scientific Scimed, Inc. | Implantable or insertable medical device resistant to microbial growth and biofilm formation |
US6887270B2 (en) | 2002-02-08 | 2005-05-03 | Boston Scientific Scimed, Inc. | Implantable or insertable medical device resistant to microbial growth and biofilm formation |
US7513093B2 (en) | 2002-10-04 | 2009-04-07 | Ethicon, Inc. | Method of preparing a packaged antimicrobial medical device |
US9597067B2 (en) | 2002-10-04 | 2017-03-21 | Ethicon, Inc. | Packaged antimicrobial medical device and method of preparing same |
US9474524B2 (en) | 2002-10-04 | 2016-10-25 | Ethicon, Inc. | Packaged antimicrobial medical device having improved shelf life and method of preparing same |
DE10355189B4 (en) * | 2003-11-26 | 2015-04-30 | Johnson & Johnson Medical Gmbh | Method for producing a surgical implant and surgical implant |
DE202004021828U1 (en) | 2004-03-09 | 2011-06-01 | Aesculap AG, 78532 | Antimicrobial medical product |
DE102004031923A1 (en) * | 2004-06-23 | 2006-01-19 | Hansgrohe Ag | Sanitary hose made of flexible plastic with antibacterial finish |
DE102004061406A1 (en) | 2004-12-21 | 2006-07-06 | Bayer Innovation Gmbh | Infection-resistant polyurethane foams, process for their preparation and use in antiseptic-treated wound dressings |
EP1924298B1 (en) | 2005-09-15 | 2010-07-14 | Aesculap AG | Biocompatible antimicrobial suture material |
AU2007221052B2 (en) | 2006-02-28 | 2013-05-16 | Covidien Lp | Antimicrobial releasing polymers |
US9981069B2 (en) | 2007-06-20 | 2018-05-29 | The Trustees Of Columbia University In The City Of New York | Bio-film resistant surfaces |
US10245025B2 (en) | 2012-04-06 | 2019-04-02 | Ethicon, Inc. | Packaged antimicrobial medical device having improved shelf life and method of preparing same |
EP3777977A1 (en) * | 2013-04-18 | 2021-02-17 | Board of Regents, The University of Texas System | Antimicrobial catheters |
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GB8820945D0 (en) * | 1988-09-07 | 1988-10-05 | Smith & Nephew | Medical articles |
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1996
- 1996-01-18 WO PCT/US1996/000842 patent/WO1996022114A1/en not_active Application Discontinuation
- 1996-01-18 AU AU47636/96A patent/AU4763696A/en not_active Abandoned
- 1996-01-18 EP EP96903614A patent/EP0804256A1/en not_active Withdrawn
- 1996-01-18 JP JP8522425A patent/JPH11500330A/en active Pending
- 1996-01-18 CA CA 2210119 patent/CA2210119A1/en not_active Abandoned
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