GB2095556A - Sterilization composition - Google Patents

Abstract

A composition for controlling the presence of unwanted micro- organisms comprising a probiocide that produces the biocide formaldehyde, an effervescent couple for evolving carbon dioxide, and optionally a surfactant.

Description

SPECIFICATION Sterilization composition DESCRIPTION This invention pertains to a composition useful for sterilizing medical, surgical, dental, laboratory and other articles of manufacture, and for controlling the presence of unwanted micro-organisms in selected environments of use. The composition comprises (1) a probiocide that produces the biocide formaldehyde, (2) an effervescent couple, and (3) optionally a surfactant.

BACKGROUND OF THE INVENTION It has long been recognized that it is highly advantageous to sterilize and substantially maintain certain articles of manufacture free of unwanted micro-organisms, and also to control the presence of unwanted micro-organisms in preselected environments of use.

One agent that is widely used for these purposes is formaldhyde solution, also known as formal in. Formaldehyde solution consists.of about 37% by weight of formaldehyde gas in water, and it usually has methanol added thereto for preventing polymerization. This solution is full strength and it is also known as formalin 100% or formalin 40. This latter designation indicates that it contains 40 grams of formaldehyde within 1 0O millileters of the solution.

While formaldehyde solution is used by the medical and dental professions for sterilizing medical, surgical and dental instruments, and by research and commercial users for sterilizing other instruments and appliances, and also for disinfecting certain areas, there are disadvantages associated with the use of formaldehyde solution. For example, formaldehyde solution commonly is used from a previously prepared stock solution, and this has the inherent disadvantage that formaldehyde vapors can continuously escape from the solution, thereby making it less effective for its intended purpose. Another disadvantage is that formaldehyde solution is heavy and expensive to ship which increases the cost of using it for sterilizing and disinfecting articles and environments.Also, formaldehyde solution is bulky and it requires cumbersome packaging, that is often damaged and leaks during transport.

In view of the above presentation, it will be appreciated, that because of the disadvantages associated with already prepared formaldehyde solutions, a critical need exists for a composition that can produce as needed a formaldehyde solution. The need exists for a composition that can produce on request a formaldehyde solution useful for obtaining the intended results of sterilizing and controlling the presence of unwanted micro-organisms.

DETAILED DESCRIPTION OF THE INVEN TION The expression "controlling the presence of micro-organisms" as used herein means in the general context of this invention killing, preventing and/or retarding the presence, or the propagation of micro-organisms in a preselected "environment of use.'' The phrase "environment of use" includes using the composition provided by this invention for controlling the presence of unwanted micro-organisms in selected areas such as hospital rooms, operating rooms, military areas, laboratories, dwellings, ships, railroad cars, stagnant water, animal dips, and the like.

The terms "biocide", "sterilizing", and "disinfectant", as used herein refer to the ability of the composition of the invention to produce formaldehyde for killing, cleansing, preventing, and/or retarding the presence, or the propagation of harmful unwanted micro-organisms on instruments and other articles of manufacture. The term "instruments" includes medical, surgical, dental, laboratory and barber instruments. The phrase "articles of manufacture" includes garbage cans, germfree boxes, containers, contact lens receptacles, and the like.

The phrase "unwanted micro-organism" as used herein includes bacteria, spirochettes, viruses, spores, fungi, mycobacin, and the like. The micro-organism include Aspergillus niger, Aspergillus flavus, Rhizopus nigricans, Cladosporium herbarium, Epidermophyton floccosum, Trichophyton mentagrophytes, Histoplasma capsulation, and the like. The phrase also includes antibacterial activity against Pseudomonas aeruginosa, Escherichia coli, Proteus vulgaris, Staphylococcus aureus, Streptococcus faecalis, Klebsiella, Enterobacter aerogenes, Proteus micabilis, and the like.

The term also embraces yeast such as Saccharomyces cerevisiae, Candida albicans and the like.

The composition of the invention comprises (1) a probiocide that produces the active biocide formaldehyde, (3) an effervescent couple, and (3) and optionally a surfactant. The probiocide are materials, which in the presence of moisture generate the biocide formaldehyde.

One probiocide suitable for this purpose is paraformaldehyde. Paraformaldehyde is a polymer selected from the group consisting of the cyclic tripolymer of the general formula (CH2O)n wherein n is 3, and the linear polymer of the general formula HO(CH2O)mH wherein m is 3 to 200. These polymers are crystalline solids, and in Pile presence of moisture they undergo depolymerization to yield the water soluble biocide and disinfectant for maidehyde. The amount of paraformaldehyde, cyclic or linear, in a composition generally is about 40% to 90% by weight based on the total weight of the composition, and more preferred about 60% to 80% of the composi tion.

Another probiocide useful for producing the biocide that can be incorporated into the composition is methenamine and its acid addition and quarternary salts. The biocide activity of a methenamine salt stems from the hydrolysis of methenamine to formaldehyde and the biocidal activity of the acid moiety of the salt.

Exemplary compounds include methenamine mandelate, methenamine salicylate, methenamine sulfosalicylate and methenamine tetraiodide. The amount of methenamine salt in a composition generally is about 40% to 90% by weight based on the total weight of the compositions, and more preferred about 60% to 80% of the composition. The composition can also include both paraformaldehyde and methenamine with the total amount of both about 40% to 90% of the composition.

The composition also can contain polyoxynethylene esters and polyoxymethylene diesters such as polyoxymethylene diacetate and mixtures thereof that have a recurring oxymethylene groups, which esters release formaldehyde in the presence of moisture and the effervescent couple. The effervescent couple comprises an acid member, which member acts as an acid catalyst on the compounds with recurring oxymethylene groups leading to the production of formaldehyde.

The effervescent couple useful for the purpose of this invention is a gas generating means for producing physical activity by the vigorously generating carbon dioxide gas. The couple, when mixed with the probiocide and an aqueous medium, produces the physical activity for mixing the formaldehyde throughout the solution for carrying out its biocidal activities. The effervescent couple comprises at least one preferably solid acidic material and a preferably solid basic material that dissolve and react in an aqueous fluid to produce carbon dioxide effervescent. The couple is mixed with the probiocide in powder, crystalline or granular form. The composition comprising the probiocide and the couple also can be manufactured in layered forms, or as a tablet.The acid member of the couple includes acids such as malic, fumaric, tartaric, itaconic, maleic, citric, adipic, succinic and mesaconic acids, and mixtures thereof. Also, inorganic acids and acid salts such as monosodium citrate, potassium acid tartrate and potassium bitartrate can be used in the composition. The basic compounds include metal carbonate and bicarbonate salts, such as alkali metal carbonates and bicarbonates, or alkaline earth carbonates and bicarbonates and mixtures thereof. Exemplary materials include the alkali metals lithium, sodium and potassium carbonate and bicarbonate, and the alkaline earth compounds magnesium and calcium carbonate or bicarbonate, Also useful are ammonium carbonate, ammonium bicarbonate and ammonium sesquecarbonate.The combination of certain of these acids and bases results in a more rapid gas production or effervescence when contacted by water; in particular, either citric acid or a mixture of citric acid and tartatic acid and sodium bicarbonate give a rapid gaseous reaction that is useful for dispensing the biocide for its intended effects. The effervescent couple is mixed with the probiocide in an anhydrous or dry state preferably in substantially stoichiometrically balanced to produce a combination that generates carbon dioxide. The amount of effervescent couple is about 1% to 40% of the composition, more preferably 5 to 20% of the composition.

The surfactants useful for the purpose of the invention include those having wetting,solubilizing and mixing properties that aid in increasing the biocide and the generated carbon dioxide gas in effecting their results. The surfactants can be cationic, anionic or nonionic. Exemplary cationic surfactants include, lauryldimethylbenzylammonium chloride, p-dii sobutyl-phenoxyethoxyethyldi methylbenzylam- monium chloride, alkydimethylbenzylammonium chloride, laurylisoquinolinium bromide, cetylethyldimethylammonium bromide, stearyldimethylbenzyl-ammonium chloride, N soya-N-ethylimorpholinium-ethosulphate N(acyl-colaminoformylmethyl) pyridinium chloride, a mixture comprising alkyl (CgH19 to C,5H31) tolymethyltrimethyl-ammonium chloride and laurylisoquinolinium bromide, coamidoalkyl betaine, and N-lauryl-myristyl -amino- propionic acid. Exemplary aminonic surfactants include linear alkylaryl sulfonates prepared by Friedel-Crafts reaction of an olefin and benzene wherein the olefin has from 10 to 1 8 carbon atoms, and the alkali metal salts thereof, and other anionc surfactants such as alkylaryl sulphonate, capryl imidazoline derivatives, dioctylester of sodium sulposcuccinic acid, sodium lauryl sulfate, sodium salt of alkylated aryl polyether sulphate, triethanolamine salt of lauryl sulphate triethanolamine salt of alkylaryl sulphonate, and mixtures thereof. Exemplary nonionic surfactants include alkylated aryl polyether alcohol, poly ethylene glycol tertdodecyl thioether, fatty acid amide condensates, aromatic polyglycol ether condensates, secondary amide of lauric acid, fatty acid alkanolamine condensates, sorbitan monolaurate, sorbitan monolaurate polyoxyethylene, sorbitan mono-oleate, sorbitan mono-oleate polyoxyetheylene deriative, mannide mono-oleate polyoxyethylene laurylether, polyoxyethylene esters of mixed resins and fatty acids, and mixtures thereof, and surfactants generically including the condensation product of a linear aliphatic alcohol having from 8 to 22 carbon atoms in its aliphatic portion and an alkylene oxide wherein the oxide consitutes from about 55 to 80% by weight of the surfactant molecule.Examples of surfactants identified by trademarks include Igepal8 CO-710 a nonionic consisting essentially of nonyl phenol condensed with 10 to 11 mols of ethylene oxide; Pluronic(D P-65 a nonionic consisting essentially of hydrophilic polyoxyethylene groups and a hydrophobic polyoxpropylene group having an average molecular weight of 3500 with 50% ethylene oxides; PluronicO P-123 a nonionic with a molecular weight of about 5650 with 30% ethylene oxide groups; DeriphatB 1 60 an ampholytic disodium N-lauryl-B-imino-di-propiote, and the like.The amount of surface active agent used is an amount sufficient to achieve the intended results, normally, the amount will range from 0.01% to about 5% by weight, based on the total weight of all the components in the composition.

The following examples will serve to further illustrate the present invention, but the invention is not intended to be limited thereto.

EXAMPLE 1 A composition is made as follows: first, 85 grams of powdered, white polymeric parafor maldehyde, 5 grams of citric acid and 1 10 grams of sodium bicarbonate are blended at a room temperature of 21"C in a dry, moisture free environment for 30 minutes to yield a homogenous blend. Next, the blend is fed into a tablet press and pressed at 5 to 6 tons pressure to produce the final tablet. The tablet when mixed with water generates an effervescent formaldehyde solution useful for sterilizing articles in need thereof. The tablet can be packaged in a moisture proof package, opened, added to water to produce as needed a biocidal solution.

EXAMPLE 2 A composition is prepared by blending in an anhydrous environment 10% citric acid, 1 9% sodium bicarbonate, 1% Igepal) surfactant, and 70% parafomaldehyde to yield a homogeneous composition. The composition is stored in a dry package to prevent premature contact with moisture. The package is comprised of two sheets of aluminium foil in faced position, defining an internal space, and with the sheets joined around their peripheries in moisture proof arrangement.

EXAMPLE 3 A composition is prepared by mixing according to the examples described above, 40 grams of paraformaldehyde, 40 grams of methenamine mandelate, 5 grams of citric acid, and 1 5 grams of potassium bicarbonate.

In one embodiment, the process for controlling the presence of unwanted micro-organisms on an article of manufacture such as a barber's scissors, is carried out by submerging the article in a solution freshly by dissolving a composition comprising paraformaldehyde, an effervescent couple and water. In the presence of water, the paraformaldehyde generates formaldehyde, and the couple generates carbon dioxide gas which mixes the formaldehyde throughout the solution for producing the intended results.

It will be understood by those versed in the disinfectant art, that in the light of the present specification and the accompanying claims, many embodiments of the invention can be made without departing from the spirit of the invention.

Claims (11)

1. In a process for disinfecting an article of manufacture, the process comprising placing the article in the presence of a composition and a liquid, wherein the composition comprises a probiocide that prodduces the biocide formaldehyde and an effervescent couple that generates carbon dioxide for mixing the biocide with the liquid, thereby contacting the article with the biocide for disinfecting same.

2. In the process for disinfecting the article according to Claim 1 wherein the liquid is water.

3. In the process for disinfecting the article according to Claim 1 wherein the probiocide is paraformaldehyde.

4. In the process for disinfecting the article according to Claim 1 wherein the probiocide is methanamine and its salts.

5. The process for disinfecting the article according to Claim 1 wherein the composition additionally comprises a surfactant.

6. The process for disinfecting the article according to Claim 1 wherein the effervescent couple comprises an inorganic or an organic acid, and an alkali metal carbonate, an alkali metal bicarbonate, an alkaline earth carbonate, or an alkaline earth bicarbonate.

7. A composition for controlling the presence of micro-organisms, said composition comprising a probiocide that produces the biocide formaldehyde in an effective amount for controlling the presence of the microorganisms, and an effervescent couple capable of evolving carbon dioxide gas for assisting in contacting the biocide with the organism, thereby controlling the presence of same.

8. The composition for controlling the presence of micro-organisms according to Claim 7 wherein the probiocide is paraformaldehyde that depolymerizes in the presence of moisture to the biocide formaldehyde.

9. The composition for controlling the presence of micro-organisms according to Claim 7 wherein the probiocide is a methenamine and its salts, which are hydrolyzed in the presence of a moisture to the biocide formaldehyde.

1 0. The composition for controlling the presence of micro-organisms according to Claim 7 wherein the probiocide has recurring oxymethylene groups and that produces the biocide formaldehyde.

11. The composition for controlling the presence of micro-organisms according to Claim 7 wherein the composition also comprises a surfactant.

1 2. The composition for controlling the presence of micro-organisms according to Claim 7 wherein the effervescent couple comprises an acid, and an alkali metal carbonate, an alkali metal bicarbonate, an alkaline earth carbonate or an alkaline earth bicarbonate.