Surgery – Means for introducing or removing material from body for... – Treating material introduced into or removed from body...
Reexamination Certificate
2002-01-18
2004-04-06
Lo, Weilun (Department: 3761)
Surgery
Means for introducing or removing material from body for...
Treating material introduced into or removed from body...
C604S328000
Reexamination Certificate
active
06716200
ABSTRACT:
FIELD OF THE INVENTION
The invention is directed to an antimicrobial urine collection system and methods of making the same.
BACKGROUND OF INVENTION
Urinary collection containers and/or drainage bags are generally used for collecting urine from a catheterized patient. Such systems typically comprise a catheter having tubing attached thereto that leads to a collection bag made of a polymer material such as PVC film. The collection bag generally includes a means for emptying the bag, such as a drainage tube.
Patients are generally catheterized either internally or externally. Cathertization often results in the possibility of urinary tract infections created from microorganism growth within the collection bag and its associated tubing. Recent studies have shown that hospital acquired or “nosocomial” urinary tract infections (UTI) affect about 900,000 Americans annually. J. R. Johnson, P. L. Roberts, R. J. Olsen, K. A. Moyer, and W. E. Stann, Prevention of Catheter Associated Urinary Tract Infection with a Oxide-Coated Urinary Catheter Clinical and Microbiologic Correlates, 162 Journal of Infectious Diseases, 1145-1150 (1990). Many of these UTIs are acquired in hospitals with the result that UTIs account for about 40% of all hospital acquired infections. Id. Of the UTIs acquired in hospitals, about 80% are catheter associated. Id. These hospital related UTIs were found to prolong hospital stays by an average of 2.4 to 4.5 days and increase the hospital cost by $558.00 per episode. Id. If the percent of catheter associated UTIs could be reduced to 0, the annual saving in hospital cost alone could be reduced by $401,760,000.00.
A source of the catheter related UTIs is suspected to be bacteria progressing from the patient's meatus through the peri-urethral space into the bladder. One known method for attempting to prevent bacterial caused UTIs is disclosed in U.S. Pat. No. 4,773,901 to Norton, the contents of which are incorporated herein by reference. In the Norton patent, the urinary catheter is coated with silver oxide to kill bacteria which may find its way down the patient's periurethral space.
In the field of urinary catheters, there is a body of art pertaining to preventing pathogens from migrating from a urine collection bag up through a catheter and into the urethra. Illustrative of this urinary catheter art are U.S. Pat. Nos. 4,529,398 by Wong; 4,661,100 by Rechsteiner; 5,267,989 by Moyet-Ortiz; 4,863,445 by Mayhan; 4,417,892 by Meisch; and 4,372,313 by Villari. The contents of each of these patents is incorporated hereby by reference.
A typical approach to preventing urinary tract infections in the urinary catheter prior art is to include a sterilizing agent in the catheter or in the collection bag so that pathogens cannot migrate up the catheter. In the Wong patent, a dispensing device having a polymer with a chemoprophylactic agent is placed within the collection bag. The dispensing device begins sterilizing liquid in the collection bag immediately upon contact, and the device is designed such that the sterilizing properties continue for an extended period of time. However, in dialysis collection bags it is desirable that the sterilization of the liquid not be commenced immediately upon contact with the dialysis collection bag, and in dialysis collection bags it is not necessary that the sterilization be contained for an extended period of time because the bag is filled in a very short period of time rather than over a period of many hours.
The Rechsteiner patent discloses a system with a urine collection bag having a fragile resinous material inside which is broken to release a sterilizing or diagnostic agent. The Rechsteiner patent is like the Wong patent in that it is designed for urinary catheter applications in which the collected urine must be sterilized immediately upon contact and over an extended period of time to prevent pathogen migration into the patient. The Mayhan patent is similar to the Rechsteiner patent, except that the resinous sterilizing agent is replaced with a slow-dissolving tablet. The Moyet-Ortiz patent discloses an antiseptic absorbent pad in a urine collection device; the Meisch patent discloses an outlet tube to a urine collection bag which is treated with a sterilizing agent to prevent pathogen colonization; the Villari patent discloses a urine collection bag with a tubular portion having a device for retaining an antimicrobial agent. These known systems can be overly complicated or otherwise less than satisfactory to construct or use.
There are many drugs, compounds, solutions, and/or materials that show antimicrobial properties, some of which are silver salts, penicillin, sulfa drugs, chlorhexidine and many others known in the art. However, many of the known antimicrobials are plagued with being heat sensitive and degrade at temperatures that are reasonable and customary for injection molding or extrusion of articles, in particular, urine collection bags. Similarly, some known antimicrobials are plagued with discoloring when exposed to light or heat, some are opaque which would render articles that need to be transparent opaque or hazy, some have odors that are noticeable to users, and some are water soluble, which in a urine collection device would leach or dissolve into the urine which would lower the amount available in the compounded article and potentially weaken the article or cause pinholes in the article.
Accordingly, there is a need for an effective antimicrobial urine collection system that provides protection from urinary tract infections for catheterized patients. It is also desirable to provide an improved method of making urine collection systems, such as by reducing the number of manufacturing steps or by making existing manufacturing systems compatible for manufacturing an antimicrobial article, or improving the final product.
SUMMARY OF THE INVENTION
The present invention is directed at an antimicrobial urine collection system and methods of making the same. In particular, the present invention is directed at an antimicrobial urine collection system comprising a catheter (such as a silicone or natural or synthetic rubber catheter), a polymer urine collection bag (such as a PVC film bag), and associated polymer or synthetic rubber tubing (such as PVC drainage and outlet tubing) that are rendered antimicrobially effective by incorporating therein an effective amount of an antimicrobial agent. The present invention is also directed at methods of making such antimicrobial urine collection systems.
A urine collection system in accordance with the invention generally includes a catheter, a urine collection bag, advantageously made from polymer film, and associated tubing. The catheter can be made of silicone or natural or synthetic rubber, the urine collection bag can be made of various polymers, such as polyvinyl chloride (PVC or vinyl), polyethylene, polypropylene, ethylene vinyl acetate, metallocene catalyzed polyethylene, or blends thereof, and the associated outlet and drainage tubing is typically made of PVC or synthetic rubber. The present invention is directed at incorporating an antimicrobially effective amount of an antimicrobial agent into the catheter, PVC film and tubing, not merely coating the outside of the polymer materials.
In one aspect of the present invention, the antimicrobial agent is a phosphoric acid metal salt, and the polymer is a PVC film and tubing. Each can advantageously comprise, by parts per hundred resin (phr), from about 0.1 to 20 phr of the antimicrobial agent, more preferably 0.5 to 7.5 phr and most preferably about 3 phr. In one embodiment of the present invention, the phosphoric acid metal salt is ADK Royalguard® BS-340 which is a commercially available stabilizing agent from Amfine Chemical Corporation of Allendale, N.J., which has been found to provide antimicrobial properties. Systems in accordance with the present invention can be made to retain the antimicrobial agent in a sustained and controlled manner.
In another aspect of the present invention, the antimicrobial agent co
Bracken Ronald L.
Lambert James M.
Bogart Michael G.
C.R. Bard Inc.
Lo Weilun
Stroock & Stroock & Lavan LLP
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