DD268396A1 - METHOD AND DEVICE FOR STERILIZING OR DISINFECTING OBJECTS - Google Patents

Abstract

The invention relates to methods and apparatus for sterilizing or disinfecting articles, in particular heat-sensitive articles in a closed chamber, preferably in an autoclave. The application is particularly in health care institutions, such as hospitals, polyclinics, etc., as well as in the pharmaceutical industry. The sterilization is carried out with a strongly oxidizing substance. An organic peracid, preferably peracetic acid in a gaseous state, is used for the application. In the closed chamber sterilization is carried out in vacuo or at normal pressure. The use of vacuum increases the drug concentration in the chamber, which significantly shortens the required sterilization time. In accordance with the method, the sterilization is preferably carried out at 40 to 50 ° C., whereby the active ingredient concentration likewise increases and short action times can be achieved with very low heat load of the sterilization material. The peracetic acid used is absolutely environmentally friendly, as it quickly disintegrates into oxygen and the unsafe acetic acid.

Description

For this 1 page drawing

Field of application of the invention

The invention relates to a method and a device for sterilizing or disinfecting articles, in particular heat-sensitive articles in a closed chamber, preferably in an autoclave. The application is particularly in health care institutions, such as hospitals, polyclinics, etc., as well as in the pharmaceutical industry.

Characteristic of the known state of the art In hospitals, etc., several methods for sterilizing heat-sensitive articles in use. The

The most important are the use of ethylene oxide, form & ici <.hydgas, glutaric dialdehyde or ß-propiolactone and the

Radiation sterilization. However, the methods used have several practical problems and disadvantages. Ethylene oxide is a substance with very high toxicity, with transport and storage difficulties. It is carcinogenic, penetrates

Deep in most Materiauon one and is held by these persistent. For this reason, the sterile goods must be aired very long, from 24 hours to months.

To make ethylene oxide safer, it is mixed with Frigengas, but which gets into the atmosphere and on this Ways to reduce the Ozoiuichicht leads. Ethylene oxide is also used in pure form. In this state it is a

highly flammable and highly explosive gas.

Recently, formaldehyde has also been used to a considerable extent. This substance is also very toxic and he can

lead to allergies. Furthermore, it has a smell that adheres to the sterile material and also penetrates into the sterile material. The

Ventilation time is about 24 hours. Furthermore, the commonly used glutaric dialdehyde should be mentioned. It is used in liquid form. To his Activation of a second substance must be used. In the subsequent rinsing and drying of the items is

the sterility endangers. For this reason we no longer talk about sterilization but only about aseptic preparation.

Another applied substance is β-propiolactone. The disadvantages of this substance are the very high toxicity and the strong

carcinogenic effect.

Radiation sterilization can not be performed in small units. It requires large expensive facilities and

extensive protective measures. As a rule, radiation stabilization on the same object is only permitted once.

According to European Patent Application 0109352, a method for sterilizing utensils is in particular known

thermolabile material known. Here, 4 to 7% peracetic acid is used as the sterilizing agent and the sterilization of the utensils is carried out at a pressure of 10 to 100 mbar. A particular disadvantage is the relatively long sterilization time.

The dilution of a commercial preparation with water according to the method is disadvantageous in two ways. First, the achievable vapor concentration goes back to mg / liter which is critical to the effect, on the other hand

At higher temperatures, a hy- rolytic decomposition of peracetic acid to acetic acid and hydrogen peroxide.

It can thus be seen that kei.i only safe method for rapid sterilization of heat-sensitive Items is available. Object of the invention

It is the object of the invention to develop a method and a device for carrying out the method with which heat-sensitive articles can be sterilized or disinfected safely, economically and environmentally friendly while avoiding the above-mentioned disadvantages.

Explanation of the essence of the invention

The object of the invention is to sterilize the objects to be sterilized, which are in a known manner in a sterile packaging, particularly suitable s.ind composite bags, using an environmentally friendly gas which penetrates the din package so that the sterility after removal from the Sterilization device is maintained.

According to the invention the object is achieved in that the sterilization or disinfection with a strong oxidizing Substance is carried out, which is an organic peracid, wherein the concentration of the applied aqueous solution of the Peracid is 7 to 50%. For the process according to the invention useful acids are, for. B. performic acid, halogenated peracetic acids, Perpropionic acid, halogenated perponic acids, perbutyric acid and its halogen compounds, perisovaleric acid and theirs Halogen compounds, percaproic acid and its halogen precursors, percrotonic acid, monopersuccinic acid, Monoperglutaric acid, perbenzoic acid and peracetic acid. In the following, only spoken of the sterilization, the statements of the invention for disinfection

apply accordingly.

The inventive method, with a concentration of peracid to 50%, ensures the desired sterilization time

from about 60 minutes.

The sterilization is possible if necessary at room temperature. Furthermore, there must be no vacuum in the chamber

The items can be both packaged and unwrapped.

Peracetic acid, which according to the method advantageously because of their easy availability, their properties and Environmental friendliness is used, decomposes according to the reaction equations

ü 0

CH ₃ -O-OQH + H ₂ Q } CH ₃ -C -UH + H ₂ O _{2 and}

0 2CH ₃ -COOH ^ 0 _? + 2CH ₃ COOH

ultimately to oxygen and harmless acetic acid.

The substance is extremely effective against all microorganisms (bacteria, fungi, viruses, spores). The device according to the invention consists of a closed chamber in which the sterilization is carried out. The Chamber is surrounded by a jacket, which serves to heat the interior of the chamber. The serving for heating the interior of the chamber jacket is advantageously a thermostat controlled Hot water jacket. The heating can also be effected by an electrical resistance surrounding the chamber. A separately arranged heating vessel with a heating element is via a pump and a water circulation

connected to the hot water jacket. An evaporator is connected to the interior of the chamber by a valve which can be shut off by a valve. In the evaporator, a spiral or a cup-shaped depression is arranged to evaporate the substance. Both can also be arranged directly in the chamber.

Eventually, a vacuum pump is connected to the interior of the chamber. At the lowest point of the cup-shaped depression a drain cock for the evaporation residue is provided. The sterilization takes place in the closed chamber, in particular in an autoclave, from which the air by means of Vacuum pump can be removed. The application of vacuum is achieved by increasing the concentration of Wiikstof (concentration in

the chamber significantly reduces the sterilization time.

Sterilization in vacuum can be carried out in such a manner that after production of the uu.rj VaI a ^P art from the

dose öterilisationsmittel is filtered off, after which if necessary then fed again such wire ¹ This Vorgehenerleichtert also increasing the drug concentration and the spread of the sterilant in the chamber.

In the chamber in which the objects to be sterilized are, to a favorable temperature

heated vapors or optionally liquid sterilants initiated. Heating of the to be evaporated

Sterilization agent is at a temperature lower than the temperature in the chamber to prevent condensation

avoid.

The process can be carried out in the temperature interval of about 2O ⁰ C to 6O ⁰ C. It is most advantageous one Use temperature of about 45 ° C, at which the heat load of the objects to be sterilized very low The evaporation can be carried out by means of a device which is in the chamber itself or in a separate evaporator

is arranged.

In practice, 10 to 300, preferably 30 to 100 ml sterilants per 10C liter Kammervoiumen to evaporate

brought, whereby it volatilizes, fills the chamber space and acts oxidizing. Thereafter, the agent is sucked through a pump and absorbed with alkali, wherein the salt diffuses the odor idi while z. For example, peracetic acid

Sodium porcetate is converted into sodium acetate. The low-process amount of the sterilizing agent according to the invention is 10 to 100 mg per liter Kammervoiumen. To the sterilizing agent is used an aqueous solution of peracid having a concentration of e.g. 7 to 50% by weight Peracetic acid. Much higher concentrations than 50% could be explosive here. The sterilant is metered directly into the device. Dilution with water does not take place. Ausfüh fiingsbeispiel

In the falling the invention will be described in detail with reference to the favorable embodiment shown in the drawing. However, the invention is in no way limited to the details of this embodiment. In the drawing, an apparatus for carrying out the method erfindun _d sgemäßen dan is .estellt.

In autoclave 1 sterilization is carried out. He is tightly closed with a door or flap 16. He will be on the desired Temperature, z. B. about 47 ⁰ C heated by means of the autoclave 1 surrounding thermostatically controlled hot water jacket 19. The water or the liquid used is arranged in the heating vessel 3 by a heating source 10

is heated. About the water circulation 2 and the pump 13 is a constant circulation of water. On

Expansion vessel 12 is disposed above the heating vessel 3 and connected thereto. The autoclave 1 is with a Thermometer 11 and possibly connected to a pressure gauge. To the autoclave 1, the vacuum pump 4 is connected so that the gaseous sterilant by a Alkaliserende Substance which is located in the container 17 is passed therethrough. It is used for this caustic soda or potassium hydroxide solution. Thereby

Odor and corrosion problems are eliminated.

The evaporator 5 is arranged separately and via the line 14 and the valve 9 with the interior of the autoclave. 1

connected. With the meter 6, the exact dosage of the sterilizing agent.

The evaporation takes place either via the spiral 7 or a cup-shaped depression at the bottom of the evaporator 5, wherein

the latter is provided with a drainage housing 20, with which the evaporation residues are discharged after sterilization.

The sterilant is heated by the heat source 8 in the evaporator 5 to about 45 ⁰ C. The temperature of the gas is

thus lower in the evaporator 5 than in the autoclave. 1

The sterilant is heated so that it evaporates but does not boil. The sterilization is carried out so that the Sterilization ^: ~ nittel ^: n the autoclave 1 through the line 14 and the valve 9 is introduced. The sterilization time is eg

1 hour.

After completion of the sterilization valve 9 is closed, the gas used for sterilization pumped out as described

and about the sterile filter 15 of the car ..! w 1 rinsed with air. The embodiment of the invention described above is merely one way of carrying out the sterilization method according to the invention. The process can also be carried out without any external or internal heating. Further, one can evaporate the sterilant either in

Connect to the evaporator 5 or inside the autoclave. The invention will be further clarified by means of the following experiments. The instruments to be sterilized were placed in a 130 liter autoclave (1-63 PES), which was sealed. The Temperature was brought to 40 ⁰ C and the system evacuated. In the autoclave, a total of 100 ml to be evaporated Peracetic acid entered and sterilization carried out for 1 hour. After completed sterilization were 17ml Acid has been consumed. The results are shown in the table below.

table Sporehffiden Speak to Experiment no. 1 Sterile 1 1 Sterile 2 1 Sterile 3 1 Sterile 4 1 Sterile 5 1 Sterile 6 1 Sterile 7 1 Sterile 8th 1 Sterile 9 1 Sterile 10

Claims (21)

A method for sterilizing or disinfecting objects, in particular heat-sensitive articles, in a closed chamber, in particular in an autoclave, wherein the sterilization or disinfection is carried out with a strongly oxidizing substance which is an organic peracid, characterized in that the Concentration of the angewanJten aqueous solution of peracid is 7 to 50%. 2. Procedure η according to claim 1, characterized in that said peracid from the group performic acid, halogenated peracetic acids, perpropionic acid, halogenated perpropionic acids, perbutyric acid and its halogen compounds, perisovaleric acid and their halogen compounds, percaproic acid and its halogen compounds, percrotonic acid, monopersuccinic acid, monoperglutaric acid, Perbcnzoesäure and peracetic acid is selected, wherein advantageously peracetic acid is used. 3. The method according to claim 1 and 2, characterized in that the amount of sterilizing or disinfecting agent in the chamber is 10 mg to 100 mg per liter of chamber volume. 4. The method according to any one of claims 1 to 3, characterized in that the concentration of the applied aqueous solution of peracid is preferably 40%. 5. The method according to any one of claims 1 to 4, characterized in that the sterilization temperature 20 ⁰ C ^ is 60 ⁰ C, advantageously about 45 ⁰ C. 6. The method according to any one of claims 1 to 5, characterized in that the sterilization or disinfection performed in a vacuum wild. 7. The method according to claim 6, characterized in that the sterilization or disinfection is carried out in a vacuum in such a way that a portion of the sterilization or disinfectant is sucked out after its dosing from the autoclave, then added sterilization or disinfectant win again to achieve a higher concentration of active ingredient in the autoclave. 8. The method according to any one of claims 1 to 5, characterized in that the sterilization or disinfection is carried out without vacuum. 9. The method according to any one of claims 1 to 8, characterized in that the sterilization or disinfectant is heated to a suitable temperature for evaporation. 10. The method according to claim 9, characterized in that the evaporation takes place in a separate device. 11. The method according to claim 9, characterized in that the evaporation takes place in the chamber itself. 12. A device for sterilizing or disinfecting objects, characterized in that it comprises a closed chamber (1) which is surrounded by a thermostatically controlled jacket (19), an evaporator (5) via a line (14) which passes through the valve (9) can be shut off, and possibly a vacuum pump (4) via a line (18) are connected to the interior of the chamber (1). 13. The apparatus according to claim 12, characterized in that the jacket (19) is a Warmwassermantei and a separately arranged heating vessel (3) via a water circulation (2) is connected thereto, in the water circulation (2) a pump (13) is and in the heating vessel (3) is a heating element (10). 14. The apparatus according to claim 13, characterized in that the heating element (10) is an electrical resistance. 15. The apparatus according to claim 13 to 14, characterized in that the circulating liquid is not water. 16. The apparatus according to claim 12, characterized in that around the chamber (1) arranged jacket (19) is replaced by an electrical resistance. 17. Device according to one of claims 12 to 15, characterized in that there are as evaporator, a spiral (7) or a cup-shaped depression in the evaporator (5). 18. Device according to one of claims 12 to 16, characterized in that the evaporation device, the spiral (7) or a cup-shaped depression are in the chamber (1). 19. Device according to one of claims 12 to 18, characterized gekannzeichnet that at the lowest point of the cup-shaped depression a drain cock (20) is arranged for the Verdamptungsrückstände. 20. Device according to ein.η of claims 12 to 19, characterized in that the chamber (1) is an autoclave. 21. Device according to one of claims 12 to 19, characterized in that the chamber (1) is a vacuum vessel.