DE10236791A1 - Preservation, disinfection or sterilization of textiles or apparatus used in medical, pharmaceutical or hygiene applications involves use of liquid carbon dioxide containing ozone - Google Patents

Abstract

Preservation, disinfection or sterilization of textiles, apparatus, utensils or other products with medical, pharmaceutical or hygiene applications by treatment with liquid carbon dioxide (CO2) is such that ozone is added to the CO2 to give a mixture.

Description

The invention relates to a preservation, disinfection and sterilization process for textile materials and utensils in medical, pharmaceutical and hygiene area based on liquid subcritical or supercritical Carbon dioxide.

In the field of medicine or pharmacy it is inevitable The necessities Utensils, such as medical instruments, pharmaceutical materials or surgical clothing, to disinfect or sterilize. With Disinfection is generally a disarming of germs, bacteria etc. meant while one understands by sterilization an absolute killing of disease carriers.

To disinfect the aforementioned items or sterilize, various methods are known. So be for example medical devices and instruments or ampoules and packaging by treatment with disinfectants, for example formaldehyde, ethylene oxide, halogen aromatic Compounds, isothiazolones or halogenated adamantane compounds, disinfected, the biocidal or bactericidal effect of this Connections is different.

Surgical linen and clothing for operating rooms or clean rooms are usually disinfected by the fact that in an autoclave previously washed parts at temperatures between 130 ° C and 150 ° C over a Treated for 15 to 60 minutes with steam. there the vapor becomes peracetic acid or another oxidizing agent added. Because of the corrosiveness of the treatment medium have to high standards be placed on the autoclave materials used, wherein however, the service life of the cleaning systems cannot be prevented is severely limited.

It is also possible instead peracetic acid Mix in methanol or 2-propanol. This is much more gentle on the material, but has the disadvantage that the Disinfection effect not as high as when using oxidizing agents is.

Other options for disinfection and / or Sterilization lies in the use of ethylene oxide, UV radiation, γ radiation or overheated Steam. However, each of these methods has disadvantages when used for the sterilization of medical or pharmaceutical commodities.

A residue of ethylene oxide, others solvents or other additives can cause hemolysis when used on or in the open wound area to lead as described by Clark et al., J. Surg., 36 (1966) and Nair, J. Biomat. Appl., 10 (1995) 121.

In contrast, the use of γ rays, UV rays or very high temperatures have negative effects, that affect the mechanical properties of the goods.

From the publications by Hayakawa et al., J. Food Sci., 59 (1994) 159. Hayakawa et al., J. Food Sci., 59 (1994) 164 and Hashizume et al., Biosci. Biotech. Biochem., 59 (1995) 1455 is the use of hydrostatic pressures in the Range from 1200 to 8000 bar is known to mechanically control the yeast cells and destroy spores. This was only possible with moderate success in connection with high temperatures as described by König et al ("Autosterilization of Biodegradable Implants by Injection Molding Process ", J. Biomed: Mater. Res., 38 (1997) 115-119).

Now it's not just desirable disinfection or sterilization costs to a minimum reduce, but also to use a process which material- and works in an environmentally friendly way. The common variant, with hot steam under additives of peracetic acid or other oxidizing agents, is relatively time and cost intensive, the textile, due to the aggressiveness of the treatment medium, after at the latest three up to four washes is no longer usable. This leads to a high proportion Textile waste, that need to be disposed of.

Another disadvantage is that the disinfectant and sterilization substances get into the wastewater after washing and the biological equilibrium in the sewage treatment plant has a lasting negative impact can influence.

For the disinfection and sterilization of surgical underwear and clothing for operating rooms and clean rooms, the German Textile Research Center North-West e. V. a process has already been developed which treats the materials described with a supercritical fluid, preferably CO ₂ , and thereby drastically reduces the number of bacteria. This takes place in that when the fluid expands, the germ cells burst and are thus killed, as in DE 39 04 513 described. The advantage of using carbon dioxide for disinfection and sterilization is that there is no waste since the carbon dioxide can be easily removed without residues.

The German patent application DE 100 58 553 discloses a fluid mixture of liquid subcritical carbon dioxide with the addition of moderators, disinfectants and / or cationic or nonionic surfactants. On the basis of the fluid mixture mentioned, a method for disinfection or sterilization for the medical and pharmaceutical field is described. Water, ethylene oxide, halogen aromatic compounds, isothiazolones or halogenated adamane were preferably used as sterilization or disinfectants tan connections used.

Based on this state of the art the task of preserving, disinfecting, and sterilization processes continue to improve and the amount of to reduce required additives.

The object is achieved by a Process for the preservation, disinfection and sterilization of textile materials as well as products, devices and utensils in the medical, pharmaceutical and hygiene areas solved at which these materials and items contain liquid subcritical or supercritical carbon dioxide treated, adding ozone to the carbon dioxide.

The ozone used to improve the sterilization / disinfection can be added to the liquid CO ₂ continuously or discontinuously. Following the treatment of the materials or objects under pressure, an expansion of the liquid or supercritical CO ₂ takes place, as a result of which the carbon dioxide returns to the gaseous state. In this way, like the gaseous ozone, it is easily separable. In addition, it is advantageous to notice that no problematic residues remain, since CO ₂ is a natural component of the atmosphere and ozone is ultimately broken down into O ₂ .

The method according to the invention is preferred carried out under subcritical conditions, although also supercritical Conditions in the pressure range from 80 to 400 bar and at one temperature from 40 to 130 ° C possible are.

According to an advantageous method, the O ₃ / O ₂ gas mixture is continuously in a stream of liquid or gaseous CO ₂ z. B. mixed in via a liquid jet gas compressor. The O ₃ / O ₂ gas mixture can be drawn in via an injector system and mixed with the liquid or gaseous CO ₂ stream. The temperature interval between 5 and 25 ° C. and the pressure range from 40 to 65 bar for the liquid CO ₂ have been found to be particularly suitable, while the O ₃ / O ₂ gas mixture advantageously has an overpressure of 0.5 to 1.0 bar with an ozone content of 7 to 15, preferably 10 to 13 wt.%.

Another method for adding CO ₂ to ozone is that the ozone generated in the customary manner is initially introduced at a pressure of 1 to 2 bar before gaseous carbon dioxide is introduced into a mixing chamber. The resulting mixture is compressed and transferred to the autoclave used for sterilization. It has proven expedient to present the ozone at a pressure of 1 to 5 bar, preferably 1 to 2 bar.

Finally, ozone and carbon dioxide can also continuously in the desired relationship be introduced into the mixing chamber before it is compressed and optionally transferred to the autoclave.

According to a preferred embodiment, the addition is from ozone 0.5 to 50 vol.%. The range is particularly preferred between 1 and 10% by volume.

Because of the lower pressures, it is advantageous to work with liquid subcritical rather than supercritical CO ₂ . In this way, a much more cost-effective and material-saving method is made available. The pressures and temperatures used in the subcritical range can be up to 73 bar and up to +31 ° C.

According to a particularly preferred embodiment the materials or objects at 50 to 60 bar as well 10 to 20 ° C preserved, sterilized and / or disinfected.

In addition to the preservation, disinfection or sterilization effect already mentioned, the carbon dioxide also has a cleaning effect owing to the density given in this state, so that prior cleaning may be dispensed with, depending on the particular contamination. Depending on requirements, the properties of the CO ₂ / O ₃ mixture can be further improved by adding individual or more moderators, preservatives, sterilizers or disinfectants and / or cationic or nonionic surfactants. In this way, fats, oils, pigment soiling and starchy soiling, for example, can also be quickly and specifically removed.

The one to be preserved, disinfectant or sterilizing good it can be items and Medical, pharmaceutical and hygienic materials act, in particular cosmetic powders, blood filters, infusion filters, Paper, leather, foils, implants, textile goods or biopolymers.

Within the scope of the present invention one understands by the term "moderators" for example Water, C1-C8 alkanols and C1-C8 carbonyl compounds, that can be used individually or in a mixture. Is particularly preferred the use of 2-propanol. The moderators are in the area from 0 to 50% by weight, but preferably 1 to 10% by weight.

Further preservatives, disinfectants and / or sterilizing agents can also be added to the CO ₂ / O ₃ mixture individually or in combination in order to further enhance the corresponding effect. The proportion is preferably 0 to 10% by weight.

In the context of the present invention, the term “further conserve Rungs-, sterilization and disinfectants "for example peracetic acid, ethylene oxide, halogen aromatic compounds, isothiazolones or halogenated adamantane compounds.

To enhance the cleaning effect can the carbon dioxide / ozone mixture one or more cationic or nonionic surfactants are added, that form reverse micelles. This includes, for example, polyethylene glycols, Polypropylene glycols, fatty alcohol ethoxylates, Pluriol PE3100, nonylphenol polyglycol ether, quaternary Quaternary ammonium salts Fatty amines, tetraalkylammonium chlorides, hydroxides, sulfates, bromides etc. The surfactants mentioned preferably have individually or in combination a proportion of 0 to 10% by weight.

To follow up on the treatment of materials or objects remove ozone, which is irritating to mucous membranes and respiratory tract Can have an effect one or more substances that catalyze the decay of ozone be added. These are typically metals such as palladium, gold or platinum, their share in the total mixture is preferably 0.01% by weight to 1.0% by weight. Alternatively, the gas mixture at or after expansion over a corresponding catalyst can be passed.

The mixture used for sterilization and / or disinfection can be regenerated by expansion. The mixture is converted from the liquid or supercritical to the gaseous state, whereupon the substances dissolved in CO ₂ precipitate out, while the gaseous CO _{2 can be} separated off and liquefied again.

If additional disinfectants are used, they can be collected, reused or disposed of in a highly concentrated form at the end of the treatment in a separator by reducing the pressure associated with converting the CO ₂ to the gaseous state.

It may be beneficial to the process upstream or downstream of a further treatment step with ozone.

Another object of the invention is the use of this method for the preservation, disinfection or sterilization of biotechnological devices, for example bioreactors or other apparatus, the devices being charged with the liquid CO ₂ / O ₃ mixture and possibly with gaseous O _3. or be treated. The CO ₂ can be mixed with moderators, preservatives, sterilizers, disinfectants, cationic or nonionic surfactants and / or substances that catalyze the decay of ozone. The gaseous ozone is expediently used in the pretreatment or aftertreatment under normal pressure or slightly elevated pressure of 1 to 2 bar.

According to a preferred form of the invention, the liquid CO ₂ / O ₃ mixture flows through the biotechnological devices, in which case pretreatment and / or post-treatment with gaseous ozone can also take place. Moderators, preservatives, sterilizers, disinfectants, cationic or nonionic surfactants and / or substances that catalyze the decomposition of ozone can in turn be added to the CO ₂ . The pretreatment and / or aftertreatment with gaseous ozone is carried out under normal pressure or a slight excess pressure of 1 to 2 bar.

The method according to the invention is as follows based on exemplary embodiments explained in more detail without however, restrict the procedure.

The disinfectant and sterilizing Effect was over the defined contamination of cotton material with selected microorganisms, especially the bacteria Escherichia coli and Staphylococcus aureus as well as the fungus Aspergillus niger.

The disinfection and sterilization treatments of the textiles were carried out in the 1 CO ₂ high pressure system shown carried out under liquid conditions. The system can be operated in both horizontal and vertical positions. It simulates a washing machine, whereby the material to be treated is located inside the rotating basket with changing direction of rotation and is accessible from all sides for the fluid and the treatment chemicals.

example 1

The autoclave with a volume of 1500 ml with built-in pressure and temperature sensor and a rotating one Basket with changing direction of rotation, in which the disinfectant or sterilizing materials have been contaminated with defined Cotton material (4 samples, 5 cm × 5 cm) loaded. The contamination was carried out by briefly storing the samples (1 min) on agar plates, that were overgrown with E. coli. The samples were run through on both sides press contaminated, being for a new agar plate was used for each sample.

After the autoclave was closed, it was filled with a mixture of carbon dioxide and ozone (100: 1) up to a pressure of 45 bar, the temperature being kept at 6 ° C. After an exposure time of 15 min, expansion was carried out in an inclined position. After the complete expansion, the samples were each placed in 50 ml of sterile SI medium. As a blank sample, a cotton sample was placed in sterile SI medium immediately after contamination. After incubation at 37 ° C. for 24 hours, the optical density of the SI media was determined using a Cary 5E spectrophotometer (from Varian). Sterile SI medium was used as the reference solution. The SI media of the cotton samples - in contrast to the blank sample - had the same optical density as the sterile SI medium, ie the samples were disinfected or sterilized by the treatment described above.

Example 2

The autoclave with a volume of 1500 ml with built-in pressure and temperature sensor and a rotating one Basket with changing direction of rotation, in which the disinfectant or Sterilizing materials were found to be contaminated with defined Cotton material (4 samples, 5 cm × 5 cm) loaded. The contamination was carried out by briefly storing the samples (1 min) Agar plates overgrown with Staphylococcus aureus. The Samples were contaminated on both sides by pressing, with one for each sample new agar plate was used.

After closing the This was autoclaved with a mixture of carbon dioxide and ozone (100: 1) filled up to a pressure of 55 bar, the temperature on Kept at 16 ° C has been. After an exposure time of 15 min, it was tilted expanded. After complete expansion, the samples were each in Given 50 ml of sterile SI medium. A cotton sample was used as a blind sample placed in sterile SI medium immediately after contamination. To 24 hours incubation at 37 ° C was the optical density of the SI media using a spectrophotometer Cary 5E (from Varian) determined. Sterile SI medium was used as the reference solution used. The SI media of the 4 cotton samples showed - in contrast to the blank test - the same optical density as the sterile SI medium, i.e. the Samples were disinfected by the treatment described above or sterilized.

Example 3

The autoclave with a volume of 1500 ml with built-in pressure and temperature sensor and a rotating one Basket with changing direction of rotation, in which the disinfectant or Sterilizing materials were found to be contaminated with defined Cotton material (4 samples, 5 cm × 5 cm) loaded. The contamination was carried out by briefly storing the samples (1 min) on agar plates, that were overgrown with Aspergillus niger. The samples were bilateral by pressing contaminated, being for a new agar plate was used for each sample.

After closing the This was autoclaved with a mixture of carbon dioxide and ozone (10: 1) filled up to a pressure of 60 bar, the temperature on Kept at 20 ° C has been. After an exposure time of 15 min, it was tilted expanded. After complete expansion, the samples were each in Given 50 ml of sterile SI medium. A cotton sample was used as a blind sample placed in sterile SI medium immediately after contamination. To 24 hours incubation at 37 ° C was the optical density of the SI media using a spectrophotometer Cary 5E (from Varian) determined. Sterile SI medium was used as the reference solution used. The SI media of the 4 cotton samples showed - in contrast to the blank test - the same optical density as the sterile SI medium, i.e. the Samples were disinfected by the treatment described above or sterilized.

Example 4

The autoclave with a volume of 1500 ml with built-in pressure and temperature sensor and a rotating one Basket with changing direction of rotation, in which the disinfectant or Sterilizing materials were found to be contaminated with defined Cotton material (4 samples, 5 cm × 5 cm) and 5 ml hexadecyltrimethylammonium chloride fed. The contamination occurred through short-term storage of the samples (1 min) on agar plates overgrown with E. coli. The samples were contaminated on both sides by pressing, with each sample a new agar plate was used.

After closing the This was autoclaved with a mixture of carbon dioxide and ozone (100: 1) filled up to a pressure of 60 bar, the temperature on Kept at 20 ° C has been. After an exposure time of 15 min, it was tilted expanded. After complete expansion, the samples were each in Given 50 ml of sterile SI medium. A cotton sample was used as a blind sample placed in sterile SI medium immediately after contamination. To 24 hours incubation at 37 ° C was the optical density of the SI media using a spectrophotometer Cary 5E (from Varian) determined. Sterile SI medium was used as the reference solution used. The SI media of the 4 cotton samples showed - in contrast to the blank test - the same optical density as the sterile SI medium, i.e. the Samples were disinfected by the treatment described above or sterilized.

Example 5

The autoclave with a volume of 1500 ml with built-in pressure and temperature sensor and a rotating basket with changing direction of rotation, in which the materials to be disinfected or sterilized were located, was defined with contaminated cotton material (4 samples, 5 cm × 5 cm) and 0.5 g of coarse palladium dust is charged. This catalyzed the decay of the ozone. Contamination was caused by briefly storing the samples (1 min) on agar plates which were coated with E. coli were overgrown. The samples were contaminated on both sides by pressing, using a new agar plate for each sample.

After closing the This was autoclaved with a mixture of carbon dioxide and ozone (100: 1) filled up to a pressure of 45 bar, the temperature on Kept at 6 ° C has been. After an exposure time of 15 min Sintered disk expands to recover the palladium. The Samples were taken after the complete Expansion was given in 50 ml sterile SI medium. As a blind test was a cotton sample immediately after contamination in sterile SI medium given. After 24 hours incubation at 37 ° C became the optical density of the SI media determined using a Cary 5E spectrophotometer (from Varian). As a reference solution sterile SI medium was used. The SI media of the 4 cotton samples pointed - in Contrary to the blind test - the same optical density as the sterile SI medium, i.e. the Samples were disinfected by the treatment described above or sterilized.

Claims (33)

Preservation, disinfection and sterilization processes for textile materials, products, devices and articles of daily use in the medical, pharmaceutical and hygiene sectors, in which the materials or articles of daily use are treated with liquid carbon dioxide, characterized in that ozone is added to the carbon dioxide in order to produce a CO ₂ To generate / O ₃ mixture. A method according to claim 1, characterized in that the CO _{2 is} subcritical and liquid. A method according to claim 1 or 2, characterized in that an O ₃ / O ₂ gas mixture is continuously introduced into a stream of liquid or gaseous CO ₂ . A method according to claim 3, characterized in that the liquid CO _{2 has} a temperature of 5 to 25 ° C and a pressure in the range of 40 to 65 bar. A method according to claim 1 or 2, characterized in that the O ₃ / O ₂ gas mixture has an overpressure of 0.5 to 1.0 bar compared to the liquid CO ₂ . Method according to one of claims 3 to 5, characterized in that the O ₃ / O ₂ gas mixture has an O ₃ content of 7 to 15% by weight. Process according to Claim 6, characterized in that the O ₃ / O ₂ gas mixture has an O ₃ content of 10 to 13% by weight. A method according to claim 1, characterized in that ozone is placed in a mixing chamber, gaseous CO _{2 is} added and the mixture is then compressed. A method according to claim 8, characterized in that the ozone is submitted with a pressure of 1 to 5 bar. A method according to claim 1, characterized in that ozone and CO _{2 are} continuously fed to a mixing chamber in the desired ratio and then compressed. Method according to one of claims 1 to 10, characterized in that the CO ₂ / O ₃ mixture has an ozone fraction of 1 to 50% by volume. A method according to claim 11, characterized in that the CO ₂ / O ₃ mixture has an ozone content of 1 to 10 vol.%. Process according to Claim 2, characterized in that liquid CO _{2 is used} in the pressure range from 55 to 70 bar and in the temperature range from 10 to 20 ° C. A method according to claim 1, characterized in that the CO _{2 is} supercritical. A method according to claim 14, characterized in that supercritical CO _{2 is used} in the pressure range from 80 to 400 bar and in the temperature range from 40 to 130 ° C. Method according to one of claims 1 to 15, characterized in that one or more moderators are added to the CO ₂ / O ₃ mixture. A method according to claim 16, characterized in that moderators from the group of water, C1-C8-alkanols or C1-C8-carbonyl compounds be used. A method according to claim 17, characterized in that as a moderator 2-propanol is used. Method according to one of claims 16 to 18, characterized in that that the Moderators a share of 0 to 50% by weight, based on the total mixture, to have. A method according to claim 19, characterized in that the moderators have a proportion of 1 to 10% by weight, based on the total mixture. Method according to one of claims 1 to 20, characterized in that one or more preservatives, sterilizing agents and / or disinfectants are added to the CO ₂ / O ₃ mixture. A method according to claim 21, characterized in that the preservation, Sterilizers and / or disinfectants a share of 0 to 10% by weight based on the total mixture. Method according to one of claims 1 to 22, characterized in that one or more cationic or nonionic surfactants are added to the CO ₂ / O ₃ mixture. Process according to claim 23, characterized in that the CO ₂ / O ₃ mixture contains, as cationic or nonionic surfactants, polyethylene glycols, polypropylene glycols, fatty alcohol ethoxylates, alkylphenol polyglycol ethers, quaternary ammonium salts, quaternary fatty amines and / or tetraalkylammonium salts. Method according to claim 23 or 24, characterized in that that the cationic or nonionic surfactants a share of 0 to 10% by weight based on the total mixture. Method according to one of claims 1 to 25, characterized in that one or more substances catalyzing the decomposition of ozone are added to the CO ₂ / O ₃ mixture. A method according to claim 26, characterized in that as the Decay of ozone catalyzing substances palladium, gold and / or Platinum can be used. A method according to claim 26 or 27, characterized in that that the the decay of ozone catalyzing substances 0.01% to 1.0% by weight, based on the total mixture. Method according to one of claims 1 to 28, characterized in that that this mixture used for preservation, sterilization and / or disinfection is regenerated by an expansion step. Method according to one of claims 1 to 29, characterized in that that this mixture used during or after the expansion step via a the decay of ozone catalyzing catalyst is directed. Method according to one of claims 1 to 30, characterized in that that the Preservatives, sterilizers and / or disinfectants the treatment of materials, products, devices or everyday objects in one Separator over a pressure reduction can be disconnected. Method according to one of claims 1 to 31, characterized in that that with gaseous ozone under normal pressure or slightly positive pressure is pretreated or post-treated up to 1 bar. Method according to one of claims 1 to 32 for the preservation, disinfection and / or sterilization of biotechnological devices and apparatus, characterized in that the device or the apparatus is charged with a liquid CO ₂ / O ₃ mixture.