WO2007076413A2

WO2007076413A2 - Antimicrobial durable medical equipment

Info

Publication number: WO2007076413A2
Application number: PCT/US2006/062428
Authority: WO
Inventors: Thomas W. Kotterer; Clifford D. Weston
Original assignee: Microban Products Company
Priority date: 2005-12-20
Filing date: 2006-12-20
Publication date: 2007-07-05
Also published as: WO2007076413A3; WO2007076413B1

Abstract

A durable medical equipment article includes a first structural element, which can be made at least in part of either a metal or a polymeric resin. An antimicrobial agent is disposed in a coating layer affixed to the surface of the metal or polymeric resin structural element. Alternatively or additionally, an antimicrobial agent can be disposed in the polymeric resin of the structural element, if the structural element is so constructed. The element and thereby the durable medical equipment article exhibits antimicrobial properties which last for the effective life of the article.

Description

ANTIMICROBIAL DURABLE MEDICAL EQUIPMENT

BACKGROUND OF THE INVENTION

[0001] The invention relates to the field of built-in antimicrobial protection and, more specifically, to a durable medical equipment article intended for use in a clinical, healthcare facility, or residential setting, the articles having imparted therein a built-in and long lasting antimicrobial characteristic. [0002] One of the challenges faced in built-in antimicrobial technology is matching an efficacious antimicrobial agent with a particular product. For example, one antimicrobial agent may work well in interior applications (e.g., interior paint) yet be unsuitable for some outdoor applications (e.g., house siding).

[0003] Similarly, an agent that works well against one type of microbe (e.g., fungi) may not work against another type of microbe (e.g., bacteria). Similarly, one may anticipate that a combination of a particular bactericide and fungicide will work to provide the degree of antimicrobial protection sought for a particular product then discover that the two active agents are incompatible or must be delivered to the product separately and thus more expensively. [0004] Equally challenging is the incorporation of an antimicrobial agent into a material, such as a polymer resin, rubber compound, or the like, without adversely changing the physical or other properties of the material or altering the efficacy of the antimicrobial agent. The chemical milieu in which the antimicrobial agent will reside, the use-life conditions it will face, and the processes under which the article will be manufactured each can reduce or destroy the antimicrobial characteristic of the agent. Conversely, the specific chemical nature of the antimicrobial agent may perturb the molecular structure of the article or its fabrication. [0005] Accordingly, imparting antimicrobial characteristics to particular products is not simply a matter of pulling an antimicrobial agent off of a shelf and adding it to an existing product. Many variables must be considered, and sometimes a commercially acceptable solution (i.e., effective and economically acceptable) is not readily apparent. Furthermore, as the field of built-in antimicrobial protection grows, each new product presents researchers with a new set of problems.

[0006] Nosocomial, or hospital acquired, infections are those that originate or occur in a hospital or hospital-like setting. Nosocomial infections are responsible for approximately 20,000 deaths annually in the United States. Roughly one-tenth of American hospital patients (i.e., 2 million every year) acquire a clinically significant nosocomial infection. [0007] Nosocomial infections generally are considered to be the result of three factors occurring in tandem: (1 ) the high prevalence of pathogens in the local environment; (2) the high prevalence of compromised hosts in that environment; and (3) efficient mechanisms of transmission from patient to patient (known as "chains of transmission"). These three major factors produce a higher likelihood of pathogen transmission within hospitals, and also the potential for the evolution of enhanced disease-causing potential among microorganisms present within hospitals. [0008] Nosocomial infections are primarily caused by opportunistic microbes, particularly by Enterococcus spp., Escherichia coli, Pseudomonas spp, and Staphylococcus aureus. Of particular concern, these microorganisms have demonstrated an ability to acquire antibiotic resistance factors. [0009]The above pathogens tend to become incorporated into the normal flora of hospital workers. Nosocomially acquired, opportunistic infections thus tend to be both very available for transmission to patients and not easily treated once infections are under way. [0010]The health care setting — be it clinical, live-in, or residential — houses a generally compromised population of potential hosts. Patients tend to be susceptible to infection through broken skin or mucous membranes (e.g. wounds).

[0011]This susceptibility exists despite the origin of such wounds. In addition, many patients are immuno-compromised. That is, their immune systems are less able to fight off infections once acquired. This status may be because of care received in the hospital or for reasons associated with their admission to the hospital.

[0012] Chain of transmission becomes a concern when the sick and immuno-susceptible are gathered into one place. A plurality of transmission routes becomes more efficient in such situations. Transmission is generally a consequence of either accidental or deliberate disregard of established protocols designed to minimize transmission between patients or from hospital workers to patients. Moreover, care providers routinely move between rooms and patients/residents in a care facility and thus can act as microbe vectors.

[0013]A durable medical equipment article, comprising a medical device having a first structural element constructed at least in part of either a metal or a polymeric resin; and a first antimicrobial agent.

[0014] The durable medical equipment article can be one of an oximeter; a stethoscope; a sphygmomanometer; an otoscope; a strength gauge; a dynamometer; a temperature probe; a temperature probe housing; a Doppler sound-based diagnostic probe; a continuous positive airway pressure device; or a housing or case for a device listed herein.

[0015] The durable medical equipment article alternatively can be one of a drug delivery device; a medical compression device; a sling; a restraint; a resuscitation equipment; a body fat analyzer; a skin-fold caliper; a pedometer; a continuous positive airway pressure device; or a housing or case for a device listed herein.

[0016] The durable medical equipment article can also be one of a bath bench; a bath seat; or an elevating toilet seat; a walker; a crutch; a cane; a grip for a walker, crutch or cane; a wheelchair; a wheelchair component; or a bariatric cushion.

[0017] It is expected that the durable medical equipment article will be composed at least in part of a polymeric material having disposed therein a first antimicrobial agent. Alternatively or additionally, the durable medical equipment article can have a first structural element constructed at least in part of a metal.

[00181 A coating can be affixed to said first structural element, such as a powder coating or a polymeric resin coating.

[0019] Suitable polymeric resins include polypropylene, polyethylene, polystyrene, acrylonitrile butadiene styrene, polyvinyl chloride, EVA, foam thermoplastic urethane, styrene-butadiene rubber, vinyl, nylon, polycarbonate, polyolefin, or polyurethane.

[0020] Antimicrobial agents appropriate for use as described herein include a quaternary ammonium compound, a gentian violet compound; a biguanide compound; an iodine compound; or a mixture of two or more of these compounds; 2,4,4'-trichloro-2-hydroxydiphenyl ether; ortho-phenyl phenol; diiodomethyl-p-tolylsulfone; 3-iodo-2-propynyl N-butylcarbamate; azoles such as propiconazole, tebuconazole or thiabendazole; 3-benzo[b]thien-2yl- 5,6-dihydro-1 ,4,2-oxathiazine 4-oxide; N-butyl-1 ,2-benzisothiazolin-3-one;

4,5-dichloro-2-octyl-3(2H)-isothiazolone; 2-n-octyl-4-isothiazolin-3-one; cyclopropyl-N'-(1 ,1 -dimethylethyl)-6-(methylthio)-1 ,3,5-triazine-2,4-diamine; or 1 ,3-dicyano-2,4,5,6-tetrachlorobenzene; a metal (e.g., silver, zinc, copper); a zinc compound; a copper compound; a titanium dioxide; or a mixture of two or more of these compounds; including wherein such metallic antimicrobial agent is in the form of a silicate, a zeolite, an amorphous glass composition, or a sol-gel composition.

DETAILED DESCRIPTION OF PREFERRED EMBOD I MENT(S) [002I]As used herein, the terms "microbe" or "microbial" should be interpreted to encompass any of the microscopic organisms commonly studied by microbiologists. Such organisms include, but are not limited to, bacteria and fungi as well as other single-celled organisms such as mold, mildew and algae. Viral particles and other infectious agents are also included in the term microbe.

[0022]The term "antimicrobial" includes biostatic activity, i.e., where the proliferation of microbiological species is reduced or eliminated, and true biocidal activity where microbiological species are killed. For ease of discussion, this detailed description may make reference to bacteria and antibacterial agents. This method of presentation should not be interpreted as limiting the scope of the invention in any way. [0023] The terms "efficacy" and "efficacious" are defined as a biostatic characteristic, such as inhibiting the growth of a microbe on a substrate. [0024] The term "non-metallic" means antimicrobial agents, other than quaternary ammonium compounds, that do not contain or utilize metal ions such as, for example, silver or copper.

[0025] In broad terms, an antimicrobial article suitable for use in a clinical setting comprising one or more antimicrobial agents disposed in or affixed to the article so as to affect a biostatic or biocidal property upon contact with a microbe.

[0026] A durable medical equipment article for use in a clinical or hospital setting can include, without limitation, a stethoscope, a sphygmomanometer, a compression device for limbs and other body parts (such as an intermittent pneumatic compression (IPC) device or a pump for the systematic application of intermittent, sequential pressure to a patient's leg, hastening venous blood flow and reducing clot risk), an equipment housing or equipment case (e.g., peristaltic pump housing), a sling, a restraint or set of restraints, and the like.

[0027] Medical equipment can further include, for example and not by way of limitation, hospital/medical bedside trays (free trays or standing trays), medical equipment carts, and bed mats. Furniture-like items typically found in clinical settings include, without limitation, a wheelchair; a counter, countertop, and other work surface; and a cart for transporting items such as computing device, medical equipment, or medical supplies. [0028]The above-listed exemplary articles or components thereof can be constructed from a variety of materials, including without limitation metal, wood, composites, laminated structures, one or more synthetic polymers, or a combination of materials.

[0029] Durable medical equipment articles suitable for clinical use include, without limitation, medical devices (such as resuscitation equipment, oximeters, sphygmomanometric equipment, controlled drug delivery devices, and the like); and electronic devices (e.g., a computer, data input device, nurse call device, or personal articles).

[0030] Such articles typically are constructed from a variety of materials, including without limitation metal, composites, synthetic polymers, or a combination of materials. [0031] Suitable polymeric resins include, without limitation, the polymeric resin is one of polypropylene, polyethylene, polystyrene, acrylonitrile butadiene styrene, polyvinyl chloride, EVA, foam thermoplastic urethane, styrene-butadiene rubber, vinyl, nylon, polycarbonate, polyolefin, or polyurethane.

[0032] The antimicrobial agents useful with the above compositions include 2,4,4'-trichloro-2-hydroxydiphenyl ether (i.e., triclosan) or other substituted or unsubstituted phenol; quaternary ammonium compounds, gentian violet compounds, biguanide compounds, iodine compounds, and mixtures thereof.

[0033] Exam plary quaternary ammonium compounds include, without limitation: alkyl-dimethyl-benzylammonium chloride, alkyl-dimethyl- ethylbenzylammonium chloride, dodecyl-dimethyl-3,4- dichlorobenzylammonium chloride, dodecyl-di-(2-hydroxyethyl)- benzylammonium chloride, dodecyl-di-(2-hydroxyethyl)-benzylammonium pentachlorophenolate, dodecyl-di-(2-hydroxyethyl)-benzylammonium 4- methylbenzoate, dodecyl-dimethyl-phenoxyethylammonium bromide, 4- diisobutyl-phenoxyethoxyethyl-dimethylben∑ylammonium chloride, 4- diisobutyl-cresoxyethoxyethyl-dimethylbenzylammonium chloride, dimethyl- didecylammonium chloride, cetyl-trimethylammonium bromide, dodecyl- pyridinium chloride, cetyl pyridinium chloride, dodecyl-isoquinolinium chloride, decamethylene-bis-4-aminoquinaldinium dichloride, alpha-(p-tolyl)- dodecyl-trimethyl-ammonium methosulphate, (dodecanoyl-N- methylaminoethyl)-(phenylcarbamoylmethyl)-dimethylammonium chloride, cetyl pyridinium chloride (1 -hexadecylpyridinium chloride), and mixtures thereof.

[0034] A non-exhaustive list of gentian violet compounds include gentian violet and dimethyl gentian violet. [0035] Exemplary substituted or unsubstituted phenols include, without limitation: phenol, mono- and poly-chlorophenols, cresols, 4-chloro-3- methylphenol, 3,5-dimethyl-4-chlorophenol, thymol, 4-chlorothymol, 4-t- amylphenol, saligenin, 4-n-hexylresorcinol, carvacrol, 2-phenylphenol, 2- benzyl-4-chlorophenol, 2,2'-dihydroxy-5,5'-dichlorodiphenylmethane, 2,2'- dihydroxy-3,3',5,5',6,6'-hexachlorodiphenylmethane, 2,2'-dihydroxy-5,5'- dichlorodiphenyl sulphide, 2,2'-dihydroxy-3,3',5₎5'-tetrachlorodiphenyl sulphide, 2-hydroxy-2',4,4'-trichlorodiphenyl ether, dibromosalicyl, 3,5- dimethyl-4-chlorophenol (chloroxylenol), thymol (isopropyl-m-cresol), and mixtures thereof. [0036] Non-limiting iodine compounds can include: potassium iodate, potassium iodide, iodine complexes (such as KI:I2 and polyvinylpyrrolidone:iodine) and iodine (herein considered an "iodine compound"). [0037] Further antimicrobial agents amenable to use in the disclosed articles and components thereof include 2,4,4'-trichloro-2-hydroxydiphenyl ether; ortho-phenyl phenol; diiodomethyl-p-tolylsulfone; 3-iodo-2-propynyl N- butylcarbamate; azoles such as propiconazole, tebuconazole or thiabendazole; 3-benzo[b]thien-2yl-5,6-dihydro-1 ,4,2-oxathiazine 4-oxide; alkyl dimethylbenzyl ammonium εaccharinate; N-butyl-1 ,2-benzisothiazolin- 3-one; 4,5-dichloro-2-octyl-3(2H)-isothiazolone; 2-n-octyl-4~isothiazolin-3- one; cyclopropyl-N'-(1 ,1 -dimethylethyl)-6-(methylthio)-1 ,3,5-triazine-2,4- diamine; 1₁3-dicyano-2,4,5,6-tetrachlorobenzene; metals (e.g., silver, zinc, copper) including metal compounds such as silicates, zeolites, amorphous glass compositions, sol-gel compositions, and the like; zinc and copper compounds such as pyrithione; titanium dioxide; or a mixture of two or more of these compounds.

[0038] The identity and amount of the particular antimicrobial agent(s) used can ,vary depending on the particular material employed. In some cases, the amount and/or type of the antimicrobial agent may vary depending on the type and amount of contamination which is likely to occur. [0039] For an article manufactured of metal (e.g. a medical cart frame, a stethoscope component, or a ), an antimicrobial powder coating can be affixed thereto. Powder coating technology is within the ken of the ordinarily skilled artisan. Antimicrobials particularly suited for use in powder coating include silver, zinc, or copper in any of elemental, zeolitic, silica or silicate, zeolitic silicate, gel-sol, and similar forms that permit the metal to function in an ion-exchange manner without need for migration of the antimicrobial agent within the powder coated layer. [0040] Turning now to a first embodiment of a medical equipment article, a stethoscope is an article manufactured of metal components (the chestpiece assembly and the eartips/eartubes) and a tubular sound-conducting member, the latter typically manufactured of a rubber or other synthetic polymeric material. [0041] An antimicrobial stethoscope can comprise a powder coat layer on one or more of the metal components thereof. Powder coating is a well- known technique for depositing a coating layer on a surface, wherein the coating layer conventionally has a pigment or other aesthetic effect therein. One or more antimicrobial agents can be disposed in the coating powder prior to the coating process. The general technique of powder coating and of disposing an antimicrobial agent within the coating powder is disclosed, for example, in GB 20020297552, the disclosure of which is incorporated by reference. [0042] Alternatively or additionally, the metal component may have disposed thereon a polymeric coating having disposed therein one or more antimicrobial agents. Several known methods exist for disposing a polymeric layer on a non-polymeric article or surface, such as dip-coating. [0043] In a second embodiment of the stethoscope, an antimicrobial agent can be disposed in the tubular member. For example, a butadiene rubber can have admixed therein a first antimicrobial agent, and the butadiene rubber mixture then used to form a tubular sound-carrying member in accordance with known manufacturing techniques. [0044] In yet another embodiment, a polymeric resin structural element can be coextruded of two or more polymeric resins. In this embodiment, a surface portion of the structural element can be composed of a first polymeric resin material having disposed therein the first antimicrobial agent. The second and subsequent layers of the coextruded structural element can be composed of a second polymeric resin material selected for any desired property, such as tensile strength, shear strength, light weight, cost, and the like. Coextrusion is a known manufacturing process to the of skill in the art. [0045] While the amount of each antimicrobial agent may vary to some extent, the amount of each antimicrobial agent must be at least a sufficient amount to exhibit an antimicrobial effect; that is, to kill or suppressing the replication of viruses, to kill or inhibit the growth of bacterial microorganisms, or to kill or suppress the replication of fungi. This amount may well be different for each specific antimicrobial agent and it is within the skilled artisan's ability to relatively easily determine an effective concentration for each antimicrobial agent. In addition, an upper limit of the concentration of the antimicrobial agent may exist under certain circumstances such as when the solubility limit of the antimicrobial agent is reached. [0046] Although the present invention has been described in considerable detail with reference to certain embodiments, one skilled in the art will appreciate that the present invention can be practiced by other than the described embodiments, which have been presented for purposes of illustration and not of limitation. Therefore, the scope of the disclosed invention should not be limited to the description of the embodiments contained herein.

Claims

CLAIMSWhat is claimed is:

1. A durable medical equipment article, comprising: a medical device having a first structural element constructed at least in part of either a metal or a polymeric resin; and a first antimicrobial agent.

2. A durable medical equipment article according to Claim 1 wherein the medical equipment article is one of an oximeter; a stethoscope; a sphygmomanometer; an otoscope; a strength gauge; a dynamometer; a temperature probe; a temperature probe housing; a Doppler sound-based diagnostic probe; a continuous positive airway pressure device; or a housing or case for a device listed herein.

3. A durable medical equipment article according to Claim 1 wherein the medical equipment article is one of a drug delivery device; a medical compression device; a sling; a restraint; a resuscitation equipment; a body fat analyzer; a skin-fold caliper; a pedometer; a continuous positive airway pressure device; or a housing or case for a device listed herein.

4. A durable medical equipment article according to Claim 1 wherein the medical equipment article is one of a bath bench; a bath seat; or an elevating toilet seat.

5. A durable medical equipment article according to Claim 1 wherein the medical equipment article is one of a walker; a crutch; a cane; a grip for a walker, crutch or cane; a wheelchair; a wheelchair component; or a bariatric cushion.

6. A durable medical equipment article according to Claim 1 wherein the medical equipment article is composed at least in part of a polymeric material having disposed therein a first antimicrobial agent.

7. A durable medical equipment article according to any of Claims 1 through 6 wherein said first structural element is constructed at least in part of a metal.

8. A durable medical equipment article according to Claim 7 wherein said coating affixed to said first structural element is a powder coating affixed to the surface of said first structural element.

9. A durable medical equipment article according to any of Claims 1 through 7 wherein said coating affixed to said first structural element is a polymeric resin coating affixed to the surface of said first structural element.

10. A durable medical equipment article according to any of Claims 1 through 6 wherein said first structural element is constructed at least in part of a polymeric resin.

1 1. A durable medical equipment article according to Claim 10 wherein said polymeric resin has disposed therein the first antimicrobial agent of the first structural element.

12. A durable medical equipment article according to any of Claims 10 and 11 wherein the polymeric resin is one of polypropylene, polyethylene, polystyrene, acrylonitrile butadiene styrene, polyvinyl chloride, EVA, foam thermoplastic urethane, styrene-butadiene rubber, vinyl, nylon, polycarbonate, polyolefin, or polyurethane.

13. A durable medical equipment article according to any of Claims

1 through 12 wherein the first antimicrobial agent is a quaternary ammonium compound, a gentian violet compound; a biguanide compound; an iodine compound; or a mixture of two or more of these compounds.

14. A durable medical equipment article according to any of Claims

1 through 12 wherein the first antimicrobial agent is 2,4,4'-trichloro-2- hydroxydiphenyl ether; ortho-phenyl phenol; diiodomethyl-p-tolylsulfone; 3- iodo-2-propynyl N-butylcarbamate; azoles such as propiconazole, tebuconazole or thiabendazole; 3-benzo[b]thien-2yl-5,6-dihydro-1 ,4,2- oxathiazine 4-oxide; N-butyl-1 ,2-benzisothiazolin-3-one; 4,5-dichloro-2-octyl- 3(2H)-isothiazolone; 2-n-octyl-4-isothiazolin-3-one; cyclopropyl-N'-(1 ,1 - dimethylethyI)-6-(methylthio)-1 ,3,5-triazine-2,4-diamine; or 1 ,3-dicyano- 2,4,5,6-tetrachlorobenzene.

15. A durable medical equipment article according to any of Claims 1 through 12 wherein the first antimicrobial agent is a metal (e.g., silver, zinc, copper); a zinc compound; a copper compound; a titanium dioxide; or a mixture of two or more of these compounds.

16. A durable medical equipment article according to Claim 15 wherein the first antimicrobial agent is a metallic antimicrobial agent in the form of a silicate, a zeolite, an amorphous glass composition, or a sol-gel composition.