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United States Patent  [ii] Patent Number: 4,660,721
Mykleby  Date of Patent: Apr. 28,1987
U. S. Patent Apr. 28,1987 Sheet 1 of2 4,660,721
 STERILIZATION PACKAGE
 Inventor: Laurie G. Mykleby, Palos Park, 111.
 Assignee: CVP Systems, Inc., Downers Grove, 111.
 Appl. No.: 848,570
 Filed: Apr. 7, 1986
 Int. CI.4 B65D 65/40; B65D 81/20
 U.S. CI 206/439; 206/438;
 Field of Search 206/438, 439, 484, 484.1,
 References Cited
U.S. PATENT DOCUMENTS
3,073,507 1/1963 Trewella et al 206/439
3,419,136 12/1968 Pratt 206/438
3,685,720 8/1972 Brady 206/484
3,768,725 10/1973 Pilaro 206/439
4,055,672 10/1977 Hirsch et al 206/439
4,057,144 11/1977 Schuster 206/439
4,203,520 5/1980 Schuster 206/439
4,367,816 1/1983 Wilkes 206/439
Primary Examiner—Stephen P. Garbe
Assistant Examiner—Brenda J. Ehrhardt
Attorney, Agent, or Firm—Thomas W. Speckman
Multi-layer sterilization package and process for sterilizing equipment wherein items are placed in the multilayer sterilization package which is adapted for use with a snorkel-type gas treatment apparatus; substantially all gas is withdrawn from the interior of the package; sterilization gas is injected into the interior and retained for a time sufficient to sterilize the equipment; sterilization gas is withdrawn from the package; and a cushioning gas is introduced into the package. The package is sealed to retain the cushioning gas, providing for effective gas leak detection.
8 Claims, 6 Drawing Figures
BACKGROUND OF THE INVENTION
1. Field of the Invention 5 This invention relates to an improved, multi-layer
sterilization package and a simplified process for sterilizing equipment, particularly medical appliances and supplies.
2. Description of the Prior Art 10 It is highly desirable to sterilize many different types
of medical appliances and supplies to eliminate contamination in the form of living microorganisms and/or macroorganisms prior to utilization of the appliances or supplies in medical, research, testing or other applica- 15 tions. It is essential to sterilize any equipment or substance which is introduced into an organism to prevent infection and contamination of the organism. Hospitals and research institutions thus require large quantities of sterile appliances and supplies in stock at all times. It is 20 important that the sterile appliances and supplies retain sterility, and are packaged in a convenient form which is easily stored and which provides convenient access to the sterile contents.
Institutions which require and use sterile appliances 25 and supplies in a large volume have essentially two choices. Prepackaged, disposable, sterile appliances and supplies may be purchased from vendors. The primary disadvantages of prepackaged, disposable, sterile appliances and supplies are that they are very costly, and that 30 many precision instruments cannot be provided in a cost effective, disposable form. The alternative to purchasing packaged, disposable, sterile equipment and supplies is to sterilize reusable equipment and supplies and after use, clean and sterilize equipment and supplies to ready 35 them for subsequent use. This process is costly because it is very labor intensive.
Several procedures for sterilizing appliances and supplies are available. One of the commonly used techniques is autoclaving, wherein objects to be sterilized 40 are subjected to elevated temperatures and pressures to exterminate any living organisms. Items are ordinarily autoclaved in a large chamber which is equipped with elaborate temperature and pressure control and containment mechanisms. Objects to be autoclaved must be 45 prepared for autoclaving; they must be clean and dry, and they must be wrapped or covered to at least some extent. Some applications require that an item be sterilized in its entirety, while other applications require only that interior surfaces or portions remain sterile. Items 50 must be carefully prepared prior to autoclaving treatment to permit elevated temperature and pressure to penetrate to the interior of the container or the packaging, and yet to provide a barrier to prevent contamination from entering the packaging after autoclaving 55 treatment. This process is extremely labor intensive, and it is also highly unreliable.
Another sterilization technique known to the art involves the use of a sterilization gas. Equipment or supplies to be sterilized may be sealed in a packaging 60 device having a gas permeable membrane. Gases present in the sealed packaging device are evacuated through the gas permeable membrane, and sterilization gas is injected into the package, again through the gas permeable membrane. The sterilization gas, after a suit- 65 able sterilization time period, may be withdrawn, if desired. Gas evacuation and. injection of many individual packages may take place simultaneously in a large
sealed chamber, which requires elaborate pressure regulation and containment'equipment.
Equipment may also be sterilized by direct exposure to ultraviolet radiation. Sterilization procedures utilizing ultraviolet radiation require extensive protective measures since ultraviolet radiation may cause very serious, permanent damage to living cells.
SUMMARY OF THE INVENTION
The improved sterilization package and process of this invention permits sterilization of individual packages of appliances and supplies using a simplified and highly reliable technique. The sterilization package comprises a multi-layer package which is adapted to be used with a snorkel-type gas evacuation and/or gas injection apparatus, or the like, which achieves gas evacuation and gas injection of individual packages. The improved sterilization package and sterilization process of this invention is cost effective and, most importantly, it is highly reliable, since the sterilization conditions can be set and monitored for each individual sterilization package. The sterilization process of this invention also provides a simple and effective gas leak detection means whereby gas leaks from individual sterilized packages are detectable to indicate that sterile conditions no longer exist.
The sterilization package and process of this invention may be utilized in connection with disposable equipment which is designed to be sterilized, used and discarded, or with reusable equipment which is thoroughly cleaned and dried after each use and prior to each sterilization procedure. The configuration and dimensions of the sterilization package may conform to any desired or required configuration to permit packaging and sterilization of very small or very large pieces of equipment or instruments, and to permit packaging and sterilization of individual instruments, pieces of equipment, or supplies, or to permit sterilization of an assembly comprising several elements, or to permit packaging and sterilization of multiple instruments or pieces of equipment in a single pouch.
The multi-layer sterilization package of this invention comprises first and second flexible, sealable, gas impermeable layers, the second layer being smaller than the first layer; a third flexible, sealable, gas permeable, but organism impervious layer attached to the second layer, the second and third layers together being about the size of the first layer; and a fourth flexible, sealable, gas impermeable layer about the same size as and attached over the third layer. The first and second flexible, gas impermeable, sealable layers comprise the major portion, or body of the sterilization package. These layers may comprise a metallic foil, such as aluminum foil, laminated on one side or coextruded with a sealable material, preferably a heat sealable material, which enables the two layers to be hermetically sealed to one another. These layers may also comprise a paper or synthetic material or laminate which is sealable and gas impermeable. The first, lower layer extend for the full length of the packaging device, while the second, upper layer extends throughout the body portion of the packaging device, for a substantial portion of the first layer, preferably about 50 to 95 percent of the entire length of the sterilization package.
The first and second layers may comprise two separate sheets of flexible, gas impermeable, sealable mate