RU2361619C1 - Disinfectant concentrate - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention concerns disinfectants on the basis of hydrogen peroxide, intended for disinfection of bacteriemically infected surfaces, potable water, systems of drinking and technical water supply, water in swimming pools, sewage. The concentrate contains, wt %: hydrogen peroxide 35-59 (in recalculation on 100% peroxide), soluble salt of silver 5-10^-6-1.5 (in recalculation on metal silver), acidity regulator - to pH not higher than 4, complexing agent - to an equimolar parity with silver cations, dimethylsulfoxide (DMSX) - 0.1-5, water - the rest. At use on a place of work, a concentrate is diluted with water to demanded working concentration.

EFFECT: reception of disinfectant solutions which, at simplification and reduction of the "know-how" of a concentrate in price, possess high stability and penetrating ability, and also the raised bactericidal activity, especially in the presence of organic pollution.

5 ex, 1 tbl

Description

The invention relates to disinfectants based on hydrogen peroxide, intended for the disinfection of bacterial contaminated surfaces, drinking water, drinking and industrial water supply systems, swimming pool water, wastewater.

For disinfection in veterinary medicine, medicine, pharmaceuticals, cosmetology, wastewater treatment, food production and many other fields, hydrogen peroxide is widely used, since it is the safest tool with a universal antimicrobial effect. Gram-positive and gram-negative bacteria, viruses, many types of pathogenic fungi are sensitive to it. However, hydrogen peroxide is not stable enough and, in addition, studies of recent years have revealed the appearance of resistance of some bacteria to hydrogen peroxide (as well as antibiotics). In addition, the bactericidal activity of hydrogen peroxide rapidly decreases in the presence of organic residues. In particular, in the instructions for the use of disinfectant based on hydrogen peroxide "Oksilizin" manufactured by NPF Ecotech LLC, it is noted that in the presence of contaminants of organic origin (milk fat, native and denatured protein), the disinfecting activity of working solutions is reduced. Therefore, prior to disinfection, preliminary cleaning of surfaces with solutions of surface-active and other detergents is required.

The bactericidal properties of silver and its compounds have been known for centuries. During this time, not a single case of addiction to it of pathogenic flora was revealed. It was found that “silver water” is more active than chlorine, bleach, sodium hypochlorite and other strong oxidizing agents, 1750 times stronger than carbolic acid and 3.5 times stronger than mercuric chloride (in the same concentration) (Kulsky L.A. Silver Water.- 9th ed., Revised and additional - K .: Science Dumka, 1987.- 134 p.). Therefore, silver salts are widely used in various disinfectant formulations.

For example, a disinfecting aqueous solution (RF patent No. 2130964) for the disinfection of various rooms and public places, containing (wt.% :):

Silver ions 0.1 · 10 ⁵ -1.0 Nitric acid or its potassium or sodium salt 0.25-5.0 Detergent 1.0-2.0 Water rest

The scope of this tool is quite limited, and to obtain it requires special equipment for electrolysis.

It was found that additional introduction of hydrogen peroxide at a concentration of 3 mg / l along with silver in drinking water provides a reliable disinfecting effect at a silver dose of 0.05 mg / l and a contact time of 20 minutes. The antimicrobial effect of silver and hydrogen peroxide persists even when additional infection with Escherichia coli is added to the water samples. With the combined action of silver and hydrogen peroxide on a microbial cell, transport processes in the cytoplasmic membrane are irreversibly inhibited and lipids of all microbe biomembranes are oxidized (Intensification of water disinfection processes. Edited by L.A. Kulsky, Kiev, Naukova Dumka, 1978, 96 pp.). With this in mind, means have been developed that include, along with hydrogen peroxide, silver salts, for example, a disinfectant concentrate for disinfection of drinking water, drinking water pipes, water supply networks, swimming pool water (RF patent No. 2187460), containing (wt.%):

Hydrogen peroxide 35-40 Silver salt 1.0-2.0 Alcohol 0.05-1.0 Water rest

The disadvantages of this invention include the low stability of the concentrate during storage caused by the catalytic effect of silver ions on the decomposition of hydrogen peroxide. This process proceeds very actively, since silver ions in the claimed composition are not bound into strong complex compounds. In addition, the working formulations of the analog have a low disinfecting ability when treating surfaces contaminated with organic substrates.

Despite the fact that hydrogen peroxide is a fairly stable product, it is possible to actively decompose concentrated solutions of hydrogen peroxide (up to an explosion) if they are contaminated, in particular, metal cations. Therefore, in order to obtain stable concentrates of disinfectants based on silver and hydrogen peroxide compounds, it is necessary to convert silver cations into strong complex compounds.

Closest to the proposed combination of essential features is the invention (US patent No. 4915955), which describes the method of preparation and composition of the disinfectant concentrate based on hydrogen peroxide. The concentrate is a solution of hydrogen peroxide 35-50% concentration containing inorganic acid (selected from the group of hydrochloric, sulfuric or phosphoric) in an amount necessary to create a pH of less than or equal to 1, 6, a silver salt or its colloidal compound in an amount of 0.05 -0.1 wt.% (In terms of metallic silver), a complexing agent, from the number of tartaric and citric acids, in the amount of 0.05-0.1 wt.%.

The method of obtaining this agent involves diluting the inorganic acid with purified water to a pH of less than or equal to 1.6, mixing the silver salt with diluted inorganic acid at 50-60 ° C, cooling to 25-30 ° C, and adding acid so that its total amount is equivalent amount of silver. At a temperature of 20-25 ° C, organic acid (tartaric or citric) is introduced to stabilize silver compounds, the mixture is homogenized. Next, the resulting mixture at a temperature of no higher than 20 ° C is mixed with 35-50% aqueous hydrogen peroxide. This product is recommended for sterilization of water, food, animal feed, surfaces, etc.

Working solutions obtained from this concentrate will not be effective enough for processing in the presence of organic impurities, which are almost always present on disinfected surfaces.

In addition, the technology for producing a disinfectant concentrate is characterized by the multiple changes in the temperature of the solutions during the synthesis of strong silver complex compounds - the main operation for obtaining a disinfectant concentrate based on silver-containing hydrogen peroxide, which significantly increases the process time, energy consumption and complicates the design of the technological process.

The objective of the present invention is to provide a means (concentrate) based on hydrogen peroxide and silver complexes, which has high stability and penetration through pollution to pathogenic flora and due to this greater efficiency and simplification, cheaper technology for producing a disinfectant concentrate.

The problem is solved by the proposed disinfectant concentrate, including hydrogen peroxide, soluble silver salt, complexing agent and acidity regulator. In this case, the tool further comprises dimethyl sulfoxide in the following ratio of components (wt.%):

Hydrogen peroxide 35.0-59.0 (in terms of 100% peroxide) Soluble silver salt 5 · 10 ^-6 -1.5 (in terms of metallic silver) Acidity regulator up to pH no more than 4 Complexing agent to equimolar ratio with silver cations Dimethyl sulfoxide 0.1-5.0 Water rest

A significant difference of the proposed tool is the inclusion in its composition of dimethyl sulfoxide in an amount of 0.1-5 wt.%

DMSO is a low-toxic substance, belongs to hazard class 4 (LD50 for various types of animals when taken with food ranges from 2 to 12 g of DMSO per 1 kg of live weight) and is approved for medical use (FS 42-2980-98) under trade brand Dimexidum.

The well-known property of dimethyl sulfoxide (DMSO) - to form complexes with almost all metals and increase the stability of other complex compounds unexpectedly allowed the synthesis of strong silver complex compounds at room temperature, which made it possible to significantly simplify and cheapen the process. As will be shown below, these simplifications did not affect the stability of highly concentrated hydrogen peroxide solutions in the presence of silver.

It is known that DMSO easily penetrates through various biomembranes, including penetrates into the bark of trees and wood (Kukushkin Yu.N. Dimethyl sulfoxide - the most important aprotic solvent. Coolant, 1997, No. 9, pp. 54-59). This is very important when disinfecting unpainted wooden surfaces, when bacterial infection has affected not only their surface, but also the volume.

As noted in numerous studies, silver has an oligodynamic nature of the action on pathogenic flora. In the presence of hydrogen peroxide, the effective bactericidal concentration of silver in working disinfecting solutions decreases and ranges from 0.005 to 100-500 mg / liter or from 5 · 10 ^-7 to 0.01-0.05 wt.% (Intensification of water disinfection processes. Ed. L.A. Kulsky, Kiev, Naukova Dumka, 1978, 96 pp.). Based on this, for a disinfectant concentrate containing 35-59% hydrogen peroxide, the effective bactericidal concentration of silver will be from 0.05 to 15000 mg / liter in terms of metallic silver or from 5 · 10 ^-6 to 1.5 wt.% .

As shown by the practice of using disinfectants obtained by the technology of the prototype, the maximum effective concentration of hydrogen peroxide in working disinfectant solutions does not exceed 5% in terms of 100% hydrogen peroxide.

The content of DMSO in the concentrate (59% hydrogen peroxide solution) should not be less than 0, 1% (see table, example 1). For less concentrated hydrogen peroxide solutions (35 and 50%), the minimum DMSO content in the disinfectant concentrate should be higher.

Hydrogen peroxide is a fairly stable product. The annual decrease in the concentration of active oxygen is allowed up to 1% per year. However, at elevated pH values (alkaline media), the solution becomes less stable and intense decomposition with oxygen evolution occurs. Therefore, concentrated solutions of hydrogen peroxide are usually adjusted to an acidic medium, where the pH does not exceed 4. Creating an acidic medium is usually carried out by adding concentrated strong mineral acids - sulfuric, nitric, phosphoric. The use of phosphoric acid as a regulator of acidity in the production of silver-containing concentrates of disinfectants is allowed, because silver phosphates in an acidic environment do not precipitate.

To obtain stable concentrates of disinfectants based on silver-containing hydrogen peroxide, it is necessary to convert silver cations of its nitric acid salt (the most common and cheap feedstock) to strong complex compounds. This is accomplished by introducing complexing agents into the concentrate composition: citric and tartaric acids, thiosulfates, thiourea, etc. The amount of complexing agent is determined by the stoichiometric reaction of the formation of the complex compound. For example, for tartaric acid, the quantitative (equimolar) ratio: silver ions / acid is 0.46, and for citric acid it is 0.59. It is most preferable to increase the amount of complexing agent by 5-10% for complete confidence in the completion of the reaction.

The most common commercially available concentrations of hydrogen peroxide are: 30%, 35%, 50%, 59%, 60% and 70% by weight. Of these, 60 and 70 percent concentrations are very dangerous for transportation and work. Therefore, it is proposed to use hydrogen peroxide with commercially available concentrations of 35, 50, and 59% for the manufacture of a disinfectant concentrate. Smaller concentrations of hydrogen peroxide increase the cost of the concentrate due to an increase in transportation costs, in terms of 100% peroxide.

The possibility of carrying out the claimed invention is shown in the following examples.

Example 1

In a dark glass vessel, a solution of 1.57 g of silver nitrate in 5 ml of distilled water is prepared, then 1.1 ml of DMSO is added with stirring. Separately, 0.5 g of tartaric acid is dissolved in 5 ml of distilled water and poured into a silver salt solution, then 0.9 ml of concentrated phosphoric acid is added with stirring. All operations are carried out at room temperature and in daylight.

Examples 2-4

The compositions of the complex compounds of silver are prepared similarly

Example 1, but with other amounts of DMSO:

example 2 - 11 ml

example 3 - 58 ml

example 4 - 123 ml

To prepare disinfectant concentrates, each of the obtained solutions of complex silver salts is dissolved in 1 liter of 50% hydrogen peroxide. Thus, the content of DMSO in concentrates of disinfectants according to examples 1-4 is (wt.%):

example 1 - 0.1

example 2 - 1,0

example 3 - 5.0

example 4 - 10.0

Example 5 (closest analogue)

Concentrated phosphoric acid is poured dropwise into 10 ml of distilled water from the burette to a pH of 1.4, after which the solution is heated to 55 ° C and, under the light of a red lamp, 1.57 g of silver nitrate is added with stirring (which corresponds to 1 g of metallic silver). Then, the resulting solution was cooled to 30 ° C and phosphoric acid was added again so that its total amount was 0.9 ml. After cooling the solution to 20 ° C., 0.5 g of tartaric acid is added with stirring.

To prepare a disinfectant concentrate according to the prototype, the resulting solution of a complex silver salt is dissolved in 1 liter of 50% hydrogen peroxide.

As already noted, hydrogen peroxide in the presence of heavy metal cations becomes unstable and can actively decompose. Therefore, the determination of the stability of metal-containing solutions of hydrogen peroxide is a mandatory controlled parameter of the process. The stability of silver-containing concentrated solutions of hydrogen peroxide was determined by the method of accelerated testing according to the method of AIL "Small Chemical Products" RSC "Applied Chemistry". The technique is based on determining the change in the concentration of hydrogen peroxide after 24 hours of exposure of the solutions at 96 ° C. The permissible absolute total error of the measurement result is ± 0.05% with a confidence level of 0.95.

The values of stability and effectiveness of disinfectant concentrates in examples 1-5 are shown in the table. These data show that DMSO additives increase the stability of silver-containing concentrates of disinfectants based on hydrogen peroxide.

Pure disinfectant concentrates in their pure form are not used for disinfection. Depending on the type and degree of bacterial infection of the surfaces, the method of applying the disinfectant, they are diluted with water. The content of the concentrate in the disinfectant ranges from 0.1 to 5-6%. The bactericidal properties of the compositions according to examples 1-5 were studied in 1% aqueous solutions of the corresponding disinfectant concentrates. The content of hydrogen peroxide and silver in disinfectant 1% solutions was constant and amounted to 0.595 and 10 ^-3 %, respectively. The amount of DMSO in disinfectant 1% solutions of the concentrate according to examples 1-4 was (wt.%):

example 1 - 0.001

example 2 - 0.01

example 3 - 0.05

example 4 - 0.10

Escherichia coli Escherichia coli was used as a test medium. A suspension containing approximately 2 · 10 ⁸ CFU / ml was prepared from its diurnal cultures. On test objects (fat-free and sterile stainless steel plates), 0.5 ml of the obtained inoculum is applied and evenly distributed on the surface. To simulate protein contamination of disinfected surfaces, 10% of the blood serum of cattle and sterile whole milk are added to the inoculum. Then, the contaminated test objects are dried and disinfection solutions are applied to them by spraying with a spray gun in the amount of 1 ml per 100 cm ^{2 of} surface. After the necessary exposure by washing in a sterile 0.5% solution of sodium bisulfite (a catalyst for undecomposed hydrogen peroxide), a sample is taken from the test objects for bacteriological studies on a solid nutrient medium. Crops are kept in a thermostat at a temperature of 37 ° C for 24 hours. In the absence of viable Escherichia coli cells, disinfection is considered effective.

The test results of the bactericidal properties of the proposed concentrate are shown in the table.

An analysis of these results shows that an increase in the concentration of DMSO in silver-containing concentrates of disinfectants based on hydrogen peroxide from 5 wt.% (Example 3) to 10 wt.% (Example 4) no longer leads to a significant increase in the stability of the concentrate and the bactericidal properties of working solutions by its basis.

The technical effect of the proposed concentrate is due to the fact that the inclusion of DMSO in the composition of the concentrate increases the stability of silver complexes, significantly facilitates the diffusion of substances associated with it through biological barriers, and gives a synergistic bactericidal effect with silver ions.

Thus, the proposed concentrate of the disinfectant is highly stable, effective, especially in the presence of organic contaminants, and easy to manufacture.

Example The composition of the bactericidal component of disinfectant solutions Disinfection time, min The stability of the concentrate,% twenty thirty 60 90 120 one 0.595% H ₂ O ₂ + 10 ^-3 % Ag + 0.001% DMSO + + ± - - 99,2 2 0.595% H ₂ O ₂ + 10 ^-3 % Ag + 0.01% DMSO + ± - - - 99.5 3 0.595% H ₂ O ₂ + 10 ^-3 % Ag + 0.05% VHI ± - - - - 99.6 four 0.595% H ₂ O ₂ + 10 ^-3 % Ag + 0.1% DMSO ± - - - - 99.7 5 0.595% H ₂ O ₂ + 10 ^-3 % Ag (closest analogue) ++ + + ± - 99.1 ++ - abundant growth
+ - multiple colonies
± - individual colonies
- - lack of growth

Claims (1)

A disinfectant concentrate including hydrogen peroxide, a soluble silver salt, a complexing agent and an acidity regulator, characterized in that it additionally contains dimethyl sulfoxide in the following ratio, wt.%:
Hydrogen peroxide 35.0-59.0 (in terms of 100% peroxide) Soluble silver salt 5-10 ^-6 -1.5 (in terms of metallic silver) Acidity regulator to pH no more than 4, Complexing agent Up to equimolar ratio with silver cations Dimethyl sulfoxide 0.1-5.0 Water Rest.