MXPA99009865A - A microbiocidal formulation - Google Patents

Abstract

The invention concerns a microbiocidal formulation suitable, following dissolution in a diluent, to form microbiocidal solution for microbiocidal treatment of an environment. The formulation comprising sufficient diluent alkalinity neutralising agent so that, following dissolution in the diluent, an alkalinity of no more than 100, preferably no more than 50 mg/l bicarbonate alkalinity is observed in the microbiocidal solution. The formulation also comprises sufficient pH neutralising agent so that, following dissolution in the diluent, a pH of 5.0-8.0, preferably 6.0-6.8, is observed in the microbiocidal solution. The formulation also comprises a microbiocidally effective amount of an alkalinity sensitive microbiocidal agent. The formulation is adapted to release the microbiocidally effective amount of the alkalinity sensitive microbiocidal agent over a microbiocidally effective period of time.

Description

A MICROBIAL FORMULATION DESCRIPTION OF THE INVENTION The present invention relates to a microbicidal formulation for dissolution in water as a diluent to form a microbicidal solution, said formulation containing an alkalinity neutralizing agent, to neutralize the total alkalinity present in the water used as the diluent. It is well known how to produce a full range of biocides, microbicides and disinfectants from halogen donors, particularly those of chlorine and iodine. Typical such donors are sodium and calcium hypochlorite, chloramines, iodophors and sodium dichloroisocyanurate (NaDCC). While the effectiveness of all these donors as a source of microbicidally effective agent, for example, hypochlorous acid, has been shown in various laboratory tests at different concentrations of the agent against a wide range of microorganisms, it has been found that, in the field , the microbicide efficiency was not as expected from the laboratory tests. After a detailed investigation and additional tests, it was surprisingly proved that the factor that most influences the effectiveness of the microbicidal solution was the water used in its preparation. The invention provides a suitable microbicidal formulation, after dissolution in a diluent to form a microbicidal solution for the microbicidal treatment of an environment, the formulation comprising sufficient alkalinity neutralizing diluent so that, after dissolution in the diluent, an alkalinity not greater than 100 is observed, preferably not higher than 50 mg / liter of bicarbonate alkalinity in the microbicidal solution; sufficient pH neutralizing agent so that, after dissolution in the diluent, a pH of 5.0 to 8.0, preferably 6.0 to 6.8, and a microbicidally effective amount of an alkalinity-sensitive microbicidal agent are observed; the formulation being adapted to release the microbicidally effective amount of the microbicidal agent responsive to alkalinity, in a microbicidally effective period of time. Preferably, the alkalinity-sensitive microbicidal agent is a source of available halogen. More preferably, the formulation is adapted to release the available halogen, in use, from an organic source / hypohalose acid precursor and / or hypohalite. Advantageously, the organic source / precursor compound releases, in aqueous solution, hypohalose acid and / or hypohalite in a microbicidally effective amount in a microbicidally effective period of time, by adapting the formulation for pH control. More advantageously, the alkalinity neutralizing agent is edible acceptable. Preferably, the organic source / precursor compound is a halogenated isocyanuric compound or a salt thereof. More preferably, the microbial compound / precursor of the hypohalous acid and / or microbicidally effective hypohalite is selected from sodium dihaloisocyanurate, potassium dihaloisocyanurate or trihaloisocyanuric acid, preferably sodium dichloroisocyanurate. Even more preferably, the microbicidally effective amount of the hypohalose acid is released from 1 to 5000 ppm of the solid source / precursor compound and the microbicidally effective time period is in the range of 10 seconds to 48 hours. Advantageously, the microorganism is selected from E. Col i o Pse udomona s or is a resistant microorganism, more preferably a microorganism resistant to pasteurization, still more preferably a thermoduric or thermophilic organism, more preferably, a species of microorganism selected from Bacillus, My crococcus, My crobacterium, Cl ostri di um, Li steri a, Al calii genes, Arthrobacter, Lactobacil lus, Serra ti a or any other spore-forming species. More advantageously, the environment comprises an external surface or a lumen of an apparatus used in the production, preparation or processing of food or beverages. Even more advantageously, the environment comprises the liquid of the process or the liquid for human or animal consumption.

Preferably, the alkalinity neutralizing agent is an edible acid or its salt or a mixture thereof, preferably an edible organic acid. More preferably, the alkalinity neutralizing agent is succinic acid or a salt thereof. Even more preferably, the alkalinity neutralizing agent is citric acid or a salt thereof. Advantageously, the microbicidal formulation is a powder, granulate or a tablet form. It is postulated that the alkalinity affects the microbicidal activity of the hypohalose acid and / or its hypohalite salts by neutralizing the hypohalous acids themselves and by affecting the pH of the microbicidal formulation in the environment. After investigation of the normal water or "field" used as the diluent, as opposed to the distilled water commonly used in laboratory tests, the alkalinity of the bicarbonate or total alkalinity was identified as the cause of the reduced effectiveness of the microbicidal solution. This explains why the results in the field were discouraging when compared to laboratory tests. It was found that the dissolved carbonate mineral salts were combined with the dissociation product of the halogen donor and reduced its availability for the microbicidal action. This was particularly noticeable where the microbicidal solution had to act at a low level (concentration of freely available low chlorine) in a large volume of diluting water. The greater the volume / proportion of diluent water compared to the microbicide, the more dissolved bicarbonate salts were available to be combined with the microbicidal agent and to significantly reduce its effectiveness. More surprisingly, this factor does not seem to have been taken into account in the prior art, and applicants are unable to find prior art on the relative microbicidal effectiveness of known microbicides in the field conditions of varying the total alkalinity of the diluent. Tests were conducted to compare laboratory tests using distilled water or water of an alkalinity known as diluent. These comparisons provided new and very surprising results with respect to the efficiency of the microbicidal agent when dissolved in the high alkalinity water as the diluent. In order to understand how the total alkalinity of "field" water could impact microbicidal activity, a study was undertaken to understand what "total alkalinity" or ANC (acid neutralizing capacity) actually was. Alkalinity is the sum of all titrable bases and is a measure of the acid neutralizing capacity (ANC). The total alkalinity in water is mainly a sum of the carbonate, bicarbonate and hydroxide levels, but may also include contributions of borates, phosphates, silicates or other bases, if these are present. Bicarbonates are the main contributors to the total alkalinity of water in the "field". The alkalinity of the water is related to the pH but it is not dependent on the pH, for example, the water can have a pH of 6.4 and an alkalinity of 320 mg / liter and, conversely, the water can have a pH of 9.0 and a alkalinity of 95 mg / liter. Reference is made to Figure 4 of the accompanying drawings, which show the lack of relationship between the pH and the total alkalinity of various waters in the field, obtained in Ireland. Geological factors are a major influence on total alkalinity levels, probably to be found in water supplies. Thus, the longer the residence time of water in a limestone / dolomite region, the greater the probability of high alkalinity. Conversely, water from granite / sand areas will have a low or lower total alkalinity. Some of the definitions used in the present have very specific meanings in relation to these and are now explained. The expression "ANC" means "acid neutralization capacity". This term is now coming into use to replace the classic expression of "total alkalinity", although the latter remains the most widely used term in the field of applied water chemistry. Outside the field of applied water chemistry, total alkalinity is like a separate concept of pH, it is not at all well understood. The terms "FAH" and "FAC" mean "freely available halogen" and "freely available chlorine", respectively, that is, halogen or chlorine in a microbicidally active form. Regarding chlorine, the total concentrations of chlorine, hypochlorous acid and hypochlorite ion are the "FAC" of the microbicidal solution - except at extremely low pH conditions, chlorine can be ignored. Figure 1 of the accompanying drawings illustrates the pH distribution curves for each of the three FAC species (it is necessary to specify a Cl concentration of 1.0 mM and a temperature of 28 ° C. Figure 2 shows distribution curves of Simplified pH for the FAC species, based on reasonably ignoring the significant Cl2 contribution when the pH is greater than 3 (it is now necessary to specify the Cl2 concentration.) Figure 3 shows the pH dependence of these two FAC species, in which the respective percentages are on a molar basis.For example, a chlorine donor compound is frequently referred to as having, say, 500 mg of available chlorine per gram.This describes the total amount of available chlorine but does not describe the form, its activity, or its availability at a given time, all of which will affect the microbicidal effectiveness of the solution.

Lubricating agents are commonly used in the tabletting process, for example, adipic acid or succinic acid. However, its only function described to date has been as a lubricating agent or as the replacement of an existing lubricant agent. No attempt has been made in the prior art to adapt these compounds or the like to act as a neutralizing agent, with respect to the impact of bicarbonate alkalinity on the effectiveness of the microbicidal agent in any given microbicidal solution. Many other compounds other than those identified above can be introduced to perform this function such as, for example, any edible acceptable acid or salt thereof. However, where practical, the level of a suitable lubricating agent must be adjusted to accommodate or neutralize the impact of the total alkalinity or the ANC value of the diluting water on the microbicidal effectiveness of any given microbicidal solution. Being aware of this, the lubricant component has been taken into account when calculating the adjustment that might be required for a "conventional" microbicidal formulation to neutralize the total alkalinity or ANC of any given diluent water. As previously stated, the total alkalinity is related to pH but is not pH dependent, and the use of an edible acid to neutralize the alkalinity had the additional benefit of reaching an optimum pH for the dissociation of the chlorine donor NaDCC. In this way, an edible acid (or a salt thereof) was selected for further testing. Since the objective of the present invention was to neutralize (reduce or eliminate) the ANC of the diluent water, once the formulation was added to the diluent water and the complete dissolution had taken place, the dosed water (formulation dissolved in the diluent) reached the target dosed pH of 5.0-8.0, preferably 6.0-6.8 and the target dosed ANC of not more than 100 mg / liter of alkalinity per bicarbonate, preferably not more than 50 mg / liter of alkalinity per bicarbonate. A tablet based on NaDCC was prepared containing, together with various components routinely employed to facilitate the formation of tablets and to promote the dissolution of the tablet by means of effervescence, an edible agent present in a quantity specifically adjusted to achieve a target pH and a PAC desired targets (free available chlorine) in the dosed water when the tablet was completely dissolved in the diluting water. The solution requires that all components of the tablet be evenly distributed in the diluent, that the solution be completely diluted at the dilution required for use as a microbicidal agent, and that after partial or virtually complete loss of dissolved carbon dioxide excess introduced by effervescence. The edible acid (or a salt thereof) may be an additional edible agent for "conventional" tablet or tabletting agents and / or effervescent agents, but the amount of edible agent must be specifically determined to achieve the desired pH and the desired FAC value, after the loss of excess dissolved carbon dioxide to an adjoining gas phase. The amount of edible agent required to produce the desired pH and FAC in the dosed water is determined by a calculation that takes into account the following factors: i) The pH of the diluent water; ii) The acid neutralization capacity (ANC), classically referred to as total alkalinity (as defined by the APHA Standards methods), of diluting water; iii) The amount of halogen donor such as NaDCC, together with the amounts of other dosifiers of a formulation, to be added to a unit volume of the diluent water; iv) The numerical values of the complete set of equilibrium constants appropriate for the diluting water conditions and defining the equilibrium conditions of the group of interconversion chemical species derived from the halogen donor, such as NaDCC, the chemical species derived from the carbonate and bicarbonate salts, the chemical species derived from any lubricating agents (including edible acids incorporated for that purpose) in the formulation, and the chemical species derived from the edible acid which serves as the pH and FAC adjusting species as defined above in this; v) The desired pH for the dosed water after complete dissolution of the formulation, after partial or virtually complete loss of excess carbon dioxide, which is defined as a "final or ultimate degree of saturation with respect to the dioxide carbon "in paragraph (vi) below; vi) The concentration of the halogen or free available chlorine donor (FAH or FAC) or alternatively, the concentration of hypochlorous acid or, alternatively, the hypochlorite ion concentration, desired for the dosed water after the complete dissolution of the formulation and loss of excessively dissolved carbon dioxide, as described in paragraph (v). The final desired concentration of FAC or hypochlorous acid or hypochlorite ion may be prescribed [but not essentially prescribed] as a fraction of the total concentration of chlorine (Cl2) introduced into the diluent water, at its desired dilution, by the NaDCC component of the formulation (Clt, expressed as mol per unit volume, is twice the number of moles of NaDCC added to the unit volume of the diluent). vii) the "degree of saturation with respect to carbon dioxide" referred to in paragraph (v), is the concentration of free carbon dioxide in water, in this case, the water dosed and completely diluted, expressed as a fraction of the concentration of free carbon dioxide that could be present if the water were in equilibrium with a contiguous gas phase for which the partial pressure of carbon dioxide is known or prescribed; viii) the concentration of "free" carbon dioxide, referred to in paragraph (vii), can be interpreted as the concentration of C02 per se [as opposed to the concentration of "dissolved" carbon dioxide, which covers the dissolved molecular species of C02, in addition to carbonic acid (H2C03) and its cleavage products, bicarbonate (HC03 ~ and carbonate ions (C032 ~)]; ix) the numerical value of the "degree of saturation with respect to carbon dioxide", which is referred to in paragraph (vii), is obtained by multiplying the partial pressure of the carbon dioxide in the gas phase by the value of Henry's law constant for carbon dioxide, for the condition of the water and for "free" carbon dioxide according to the alternatives described in paragraph (viii). Investigating the impact of total alkalinity or ANC on microbicidal efficacy in an effervescent tablet formulation containing an active ingredient commonly used as a halogen donor (NaDCC) clearly demonstrates that, when alkalinity is taken into consideration and an agent for neutralizing it is added to the formulation, there is an immediate improvement of microbicidal efficiency, as shown in the comparative tests described in the following examples. These laboratory tests were carried out with three chlorine donors, such as the chosen halogen, because chlorine is a halogen commonly used in commercial microbicides, namely sodium hypochlorite; a product based on commercial NaDCC, Agrisept® Tablets; and a test product, the same formulation as the Agrisept® Tablets, but which also contains an agent to neutralize the alkalinity of the diluent. Typically, if the aforementioned calculation is applied, then, as two critical factors are varied, also the required amount of the alkalinity neutralizing agent varies. It has also been found that the two factors that are most likely altered by field conditions are the total alkalinity or ANC of the diluting water; and the volume of the diluting water. It is clear that when the ANC is increased, then the required amount of the alkalinity neutralizing agent is also increased. However, it must be remembered that when the volume of diluent water is increased, the total amount of ANC in the water is also increased, while the amount of neutralizing agent of the alkalinity in any given tablet formulation, is fixed. By using a predictive computer program, based on the above-mentioned factors (i) to (ix), it is possible to calculate how to vary the amount of two alkalinity neutralizing agents, potentials, citric acid and succinic acid, to achieve the target, dosed ANC value, using a specified volume of a diluent and using different volumes of a diluent. Table 1 shows, using the predictive computer program, the impact of altering the diluent ANC, while maintaining all other constant factors. The formulation comprises (excluding the alkalinity reducing agent) 2.21 g of NaDCC, 1.13 g of adipic acid, 1.036 g of sodium bicarbonate and 0.044 g of sodium carbonate. The pH of the diluent water is 7.5 and its volume is 1 liter. The proportion of dosed pH and target FAC to total Cl are 6.0 and 0.5, respectively.

Table 1 Table 2 shows, using the predictive computer program, the impact of altering the volume of the diluent, while maintaining all other constant factors. The formulation comprises (excluding the alkalinity neutralizing agent) 2.21 g of NaDCC, 1.13 g of adipic acid, 1036 g of sodium bicarbonate and 0.044 g of sodium carbonate. The pH of the diluent water is 7.5 and its volume is 10 liters. The proportion of pH and FAC dosed objective to total chlorine are 6.0 and 0.5, respectively.

Table 2 Table 3 shows the impact of altering the amount of adipic acid (the conventional lubricating agent), while keeping all other factors constant. The composition of the formulation is as described above in Tables 1 and 2. The volume of the diluent water is 1 liter, its pH is 7.5 and its total alkalinity is 400 mg / liter. The proportion of pH and FAC dosed objective to total chlorine are 6.0 and 0.5, respectively.

Table 3 The impact on the microbicidal efficiency of halogen-based microbicides, in particular, and more generally, of any microbicide whose activity in solution is influenced or degraded by the ANC value of the diluent water, is as follows: Table 4 It will be appreciated that the microbicidal formulation of the present invention is particularly applicable to the neutralization of the medium and major negative impacts described hereinabove, and is more particularly applicable to the neutralization of the major negative impacts described hereinbefore. The invention will now be understood in greater detail from the following description of the preferred embodiments thereof, given by way of example only.

Example 1 A microbicidal formulation of the present invention has the following preferred composition: A 1% aqueous solution of sodium dichloroisocyanurate has a pH in the range of 5.5 to 7.0. The incorporation of an alkalinity reducing agent such as succinic acid ensures that the alkalinity, which is mainly alkalinity by bicarbonate, is neutralized. This ensures that the nominal amount of the hypochlorous acid and / or the hypochlorite salt present in the sodium dichloroisocyanurate solution is effectively available. The final pH will of course determine the relative amounts of the hypochlorous acid and the hypochlorite salt present. The incorporation of adipic acid ensures a stable formula, suitable for the formation of tablets and the incorporation of effervescent excipients ensures the effective and rapid release of hypochlorous acid and / or hypochlorite salt towards the solution, from the source. It will be appreciated that the identity of the excipients may be changed or the excipients may be eliminated, depending on the final requirements or the conditions under which the microbicidal formulation of the present invention is to be used. The microbicidal formulation of the present invention will also be suitable for use in the form of a powder, granulate or tablet, each of which allows the precise quantification of the microbicidally inactive source and the amounts of excipient, in a given volume of water or any other suitable solvent. The studies described in the remaining examples were carried out with tablets of the microbicidal formulation of the invention, which has the following composition: Ingredient Weight (g / tablet) Succinic acid 5.00 Sodium dichloroisocyanurate 2.21 Sodium bicarbonate 1.036 Adipic acid 1.13 Sodium carbonate 0.044 Total weight of tablet 9.42 The alkalinity reducing agent can be integrally incorporated into the microbicidal formulation. Alternatively, the alkalinity reducing agent may be present in a coating on a powder, granulate or tablet of the microbicidal formulation and, in that case, the alkalinity reducing agent is released to the solution, to reduce the level of alkalinity, before the microbicidally active agent is released into the solution. It will be appreciated that there is no need for a tableting or lubricating agent in a powder or granulation formulation. The desired pH of the final solution, in the case of sodium dichloroisocyanurate as the microbicidally inactive source, is in the range of 5.0-8.0, preferably 6.0-6.8.

The dissociation of hypochlorous acid in the hypochlorite ion is pH dependent. Thus, at pH 6.0, 97.3% of the hypochlorous acid is not dissociated and, at pH 7.0, 78.1% of the hypochlorous acid is not dissociated. It is preferred that the anhydrous form of the microbicidally inactive source be employed in the present microbicidal formulations.

Example 2 The effect of varying the alkalinity of the water on the pH of the microbicidal formulation in the environment was investigated as follows: Hard water, with a hardness of 342 mg / ml, is prepared by dissolving 304 mg of sodium chloride. calcium and 139 mg of MgCl2 # 6H20 in 1 liter of deionized water. Hard water, with an alkalinity of 100 mg / liter, 200 mg / liter or 300 mg / liter is prepared by dissolving 200 mg, 400 mg or 600 mg of NaHCO3, with 304 mg of CaCl2 and 139 mg of MgCl2 »6H20 in 1 liter of deionized water. The microbicidal formulation of the present invention comprises a tablet of 9.42 g of Example 1 dissolved in sufficient hard water of 0.100 mg / liter, 200 mg / liter or 300 mg / liter of added alkalinity, to produce 25 ppm of available chlorine. The comparative formulation has the following composition: Ingredient Weight (% by weight per tablet) Sodium dichloroisocyanurate 50 Sodium bicarbonate 22 Adipic acid 24 Sodium carbonate 4 One tablet (5 g) of the comparative formulation is dissolved in sufficient hard water of 0.100 mg / liter, 200 mg / liter or 300 mg / liter of added alkalinity, to yield 25 ppm of available chlorine. In each case, the pH was measured at 10 ° C and the results are shown in Table 5.

Table 5: Effect of Alkalinity on pH An impact of alkalinity on the dissociation of hypochlorous acid in hypochlorite and, therefore, on microbicidal efficacy is suggested by the aforementioned results. Thus, current experimental data generated in standard hard water is likely to be inaccurate in field conditions where alkalinity is frequently present. It is clear that the added alkalinity affects the pH of the comparative formulation solution and the formulation of the solution of the invention. Specifically, when the added alkalinity is greater than 100 mg / liter, the pH of the comparative formulation solution is outside the desired pH range of 6.0 to 6.8. In contrast, even when the added alkalinity is 300 mg / liter, the pH of the formulation of the solution of the invention is still within the desired pH range of 6.0-6.8.

Example 3 The usual recommended method to carry out the cleaning and disinfection of automated milking system is known as cold circulation cleaning. Using this procedure, the lumen or internal diameter of the milking system is pre-rinsed at the end of the morning milking process, with cold water, followed by a washing sequence that involves the circulation of 45 liters of a detergent solution containing 0.5% (227 g / 45 liters (0.5 lbs / 10 gallons)) of an approved caustic detergent, for 10 minutes, whose detergent solution is then recovered in the wash through reuse in the second daily wash. It is suggested not to carry out a post-rinse of the residue of the caustic solution from the lumen until immediately before the next milking, since it is believed that successful cleaning and microbicidal action on the lumen of the milking system depend on the prolonged contact of this caustic residue with the surfaces of the lumen. A warm wash at regular intervals is an essential part of the routine to eliminate the constitution of milk deposits, among other things. In order to obtain optimal results from cold cleaning, the following instructions are widely acceptable: Prescribed Routines: A) Cold Circulation Cleaning Wash the jet jets and remove the clusters and attach them to the jet jets. Rinse the lumen of the system with 14 liters (3 gallons) of cold water per cluster. Dissolve an approved caustic detergent in cold water at a rate of 227 g / 45 liters (0.5 lbs / 10 gallons) leaving approximately 9 liters (2 gallons) of the solution per cluster. Circulate the solution for 10 minutes having allowed the first 5 liters (1 gallon) to run to the waste. Return all the solution to the washing from side to side and hold for the second daily washing. Leave the clusters on the jet jets. Before the next milking, rinse the lumen of the system with 14 liters (3 gallons) of cold water per cluster to remove the residue of the caustic detergent. Add 28 ml (1 fluid ounce) of agricultural grade hypochlorite to the final 67 liters (10 gallons) of rinse water.

B) Regular hot wash (recommended at night intervals).

The data described in Table 6 were obtained from two milking parlors on the same farm, one of which (control room) used the prescribed routine mentioned above and the other of which (test room) used the following routine alternative.

Alternative Routine for Milking Systems Wash the jet jets and remove the clusters and attach them to the jet jets.

Rinse the milking system from side to side with 14 liters of cold clean water per cluster. Dissolve an approved caustic detergent in cold water at a rate of 227 g / 45 liters (0.5 lbs / 10 gallons) leaving approximately 9 liters (2 gallons) of the solution per cluster. Perform this cold wash every day and use twice only. Having allowed the first 5 liters (1 gallon) to run to the waste, the solution is circulated for 10 minutes. Return all the remaining solution to the washing from side to side and hold for a second daily wash. Leave the clusters on the jet jets. Then, post-rinse (at 2 pm after morning use or immediately after evening use) the system with 14 liters (3 gallons) of cold clean water per cluster, remove all traces of the caustic detergent residue. Prepare a microbicidal formulation of the invention (dissolve two tablets of 9.42 g in about 1 liter of water, the tablet comprises 5.0 g of succinic acid, 2.21 g of sodium dichloroisocyanurate, 1.036 g of sodium bicarbonate, 1.13 g of adipic acid and 0.044 g of sodium carbonate) and add the same to 66 liters of the rinse water of the final rinse cycle. Suction through the milking system and let drain completely.

The tests were continued for two weeks. Table 6 gives the results of week 1 and week 2 of the microbiological count of the plant rinses after circulation during the test.

Table 6: Microbiological account of the rinses in the plant (account for my rinse water) Microbiological Account Week 1 Week 2 Control Test Control Test Total bacterial count 1300 380 600 410 Psychotrophic 340 119 80 5 Thermodynamic 3 1 4 5 The total bacterial counts and the psychotrophic accounts for each of week 1 and week 2 show superior performance for the microbicidal formulation of the present invention. In addition, there was little evidence of a protein-like film constitution after two weeks of use of the microbicidal solution of the invention.

Example 4 A laboratory comparison was carried out to determine the microbicidal efficacy of the test formulation as described in Example 1, of the comparative formulation (5 g tablets) as described in Example 2 and of a hypochlorite solution of sodium (Merck), supplied by Lennox Chemicals, Dublin, Ireland. The objective was to establish that the formulation of the present invention was more effective as a microbicide than a conventional solution of sodium hypochlorite and a conventional formulation in tablet form, as for Example 2, in "field" water. The general format of the test scheme is derived from BS3286: 1960. The tests were carried out using 0.1% milk as an organic load. The milk used was unpasteurized milk with an approximate somatic cell count of 300 x 103. The test organisms were Staphyl ococcus a ureus, isolated from a clinical case of mastitis in dairy cows, and Ba ci ll us s ub ti lis , a control crop obtained from the ATCC. The contact times for the three products were 5 minutes, 10 minutes, 6 hours and 24 hours.

The concentrations of the three products were 25 ppm (mg / liter) of available chlorine. The tests were carried out at 10 ° C. The dilutions in all cases were made in a diluent comprising water with an alkalinity of 300 mg / liter expressed as calcium carbonate equivalent (CaC0) and a hardness of 342 mg / liter expressed as calcium carbonate (CaC03). The pH of the water was checked before and after the addition of the test product. Inactivation of the products under test is carried out by placing 1 ml of the reactive mixture, after the appropriate contact time, in 9 ml of sterile inactivation fluid. Inactivation will neutralize the effect of the disinfectant. Dilutions were made at the aforementioned contact times, and the inactivated fluids were cultured on blood agar and MacConkey agar using standard laboratory practices. Incubation was carried out for 18-24 hours at 37 ° C. The inoculum consisted of 6 ml of the test organism (1 x 104 organisms / ml) plus 4 ml of 0.1% milk. The proportion of the disinfectant dilution: inoculum was 50:50. The controls replaced the water, for example, water with a hardness of 342 mg / liter and an alkalinity of 300 mg / liter, instead of the test product. The minimum level (approval criteria) that is required will be 99.99% on the viable account (cfu / ml). The inactivation fluid comprises soy lecithin (3 g), Tween 80 (30 ml), sodium thiosulfate (5 g), L-histidine (1 g), phosphate buffer (0.25 N); 10 ml), and purified water - volume up to 1 liter. The inactivation fluid was sterilized at 121 ° C for 15 minutes. The "field" diluent comprises NaHCO3 (600 mg), CaCl2 (304 mg) and MgCl2 »6H20 (1339 mg), which is lowered to 1,000 ml with deionized water.

RESULTS Table 7 Table 8 Organism: Bacillus subtilis N / G = No growth Control account 1 x 104 * The indication of > 100 cfu / ml means that the organisms were too numerous to quantify.

Table 9 Organism: Staphyl ococcus a ureus N / G = No growth Control account 1 x 10"Example 5 A laboratory comparison of the efficiency of a test formulation as described in Example 1 against the conventional microbicide, sodium hypochlorite, at two different concentrations, under control conditions. The objective was to establish that the formulation of the present invention was more effective as a microbicide at a very low concentration, 25 ppm, when compared to sodium hypochlorite and that, even if the concentration was increased, by a factor of 10, up to 250 ppm, the formulation of the present invention was much more efficient in "field" water. The test procedure of Example 4 was followed, with the following amendments. The test organisms were Ba ci l l u s s ub ti l i s, Salmonella typhimurium (phage type 104), Listeria monocytogenes and Clostridium butyricum. The concentrations were 25 ppm and 250 ppm for each of the hypochlorite and the formulation of the present invention. The organic load was 0.1% milk (25 ppm) or 5% yeast (250 ppm).

Table 10 Organism: Salmonella typhimurium phage type 104 Table 11 Organism: Listeria monocytogenes Table 12 Organism: Clostridium butyricum Table 13 Organization: Bacil l us subtili s These data demonstrate the difference between sodium hypochlorite and the formulation of the present invention. The test was carried out simultaneously on both products at two different concentrations, 25 ppm and 250 ppm. The results of the test clearly demonstrate that, at 250 ppm, the formulation of the present invention is microbicidally superior to conventional hypochlorite. At 25 ppm, the difference is smaller but, in most cases, the formulation of the present invention is still superior.

Example 6 Formulation (A) Weight Formulated total .... 3.2 grams Composition: Sodium dichloroisocyanurate.25% (w / w) 800 mg Sodium bicarbonate 35% (w / w) 1120 mg Sodium carbonate 5% (w / w) 160 mg Succinic acid 35% (w / w) 1130 mg Formulation (B) Weight Formulated total .... 5.56 grams Composition: Sodium dichloroisocyanurate 14.39% (w / w) 800 mg Sodium bicarbonate 20.14% (w / w) 1120 mg Sodium carbonate 2.88% (w / w) 160 mg Succinic acid 62.59% (w / w) 3480 mg El The general format of the test scheme is derived from BS3286: 1960 and the test procedure of Example 4 was followed, with the following amendments. The tests were carried out using 0.1% milk as an organic load. The test organism was Ba ci l us s ub ti l i s BGA, a control culture obtained from ATCC. The contact time for each of the formulations was 5 minutes, 10 minutes, 1 hour and 6 hours. The concentration of each formulation was 100 ppm (mg / liter) of available chlorine in a volume of 5 liters of diluting water. All tests were carried out at 10 ° C. The diluent water had a total alkalinity of 400 mg / liter expressed as calcium carbonate (CaC03) equivalent and a hardness of 342 mg / liter expressed as calcium carbonate (CaC03). The pH of the water was measured before and after the addition of the various formulations. The inactivated fluids were cultured on Colombian Blood Agar using standard laboratory practices. Incubation was for 18 hours at 37 ° C. The inoculum concentration was 1.25 x 106 organisms / ml. The "field" diluent comprises NaHC03 (750 mg), CaCl2 (304 mg) and MgCl2 «6H20 (1339 mg), which is lowered to 1,000 ml with deionized water.

Table 14 Table 15 The indication of > 100 cfu / ml means that the organisms were too numerous to quantify.

The results show that Test Formulation B is superior to Test Formulation A in suppressing the development of Bacillus subtypes BGA under the conditions described. The residual resistance of the organism is due to several factors that limit the microbicidal activity of the formulation, specifically, its spore form, the high concentration of the inoculum organism used and the high total alkalinity of the diluent. It will be appreciated that the microbicidal formulation of the present invention has applicability in a milking apparatus at the end of a washing procedure of the post-milking apparatus (as exemplified in example 3); in any pre-pasteurization retention system; and in any post-pasteurization apparatus against contaminating microorganisms after pasteurization. Although the aforementioned results concern the sterilization of the lumen or internal diameter of a milking apparatus, it is expected that the microbicidal formulations of the present invention will be particularly suitable for the treatment of water, where the World Health Organization (WHO) has now set the limit for residual chlorine in treated water to only 5 mg / liter. Thus, with conventional microbicidal formulations, such water is being inadequately treated, since at least some of the hypohalose / hypohalite salt is being neutralized by the present alkalinity and, if conventional microbicidal formulation is provided in excess, then, in areas of low alkalinity, the WHO limit may be exceeded. It will be appreciated, therefore, that the microbicidal formulations of the present invention provide effective water treatment by giving the effective microbicidal effect without exceeding the limits recommended by the WHO. It will also be appreciated that the microbicidal formulation of the present invention, although exemplified with respect to a milking apparatus, has general applicability in any apparatus used in the production, preparation or processing of food or beverages and, of course, in the treatment of water. for human or animal consumption or process liquids.

Example 7 Sodium dichloroisocyanurate 2,210 g Adipic acid 1,130 g Sodium bicarbonate 1,036 g Sodium carbonate = 0,044 g Succinic acid = 0.561 g A microbicidal formulation of the above composition is useful, after dissolution in five liters of a diluent having a pH of 7.5, a total alkalinity of 100 mg / liter as calcium carbonate and a total carbon carbon content of 2.1 mmol / l. liter (calculated) to achieve, after dissolution in the diluent, a pH of 6.0 and a ratio of FAC to total Cl of 1.0.

Example 8 Sodium dichloroisocyanurate = 2.210 g Adipic acid = 1.130 g Sodium bicarbonate = 1.036 g Sodium carbonate = 0.044 g Succinic acid = 2.619 g A microbicidal formulation of the aforementioned composition is useful, after dissolution in five liters of a diluent having a pH of 7.5, a total alkalinity of 400 mg / liter as calcium carbonate and a total carbon carbon content of 8.5 mmol / liter (calculated) to achieve, after dissolution in the diluent, a pH of 6.0 and a ratio of FAC to total Cl of 1.0.

Example 9 Sodium dichloroisocyanurate = 2.210 g Adipic acid = 1.130 g Sodium bicarbonate = 1.036 g Sodium carbonate = 0.044 g Succinic acid = 0.218 g A microbicidal formulation of the aforementioned composition is useful, after dissolution in five liters of a diluent having a pH of 7.5, a total alkalinity of 50 mg / liter as calcium carbonate and a total carbon carbon content of 1.1 mmol / liter (calculated) to achieve, after dissolution in the diluent, a pH of 6.0 and a ratio of FAC to total Cl of 1.0.

Example 10 Sodium dichloroisocyanurate = 2.210 g Adipic acid = 1.130 g Sodium bicarbonate = 1.036 g Sodium carbonate = 0.044 g Succinic acid = 13,589 g A microbicidal formulation of the aforementioned composition is useful, after dissolution in twenty-five liters of a diluent having a pH of 7.5, a total alkalinity of 400 mg / liter as calcium carbonate and a total carbon-carbon content of 8.5 mmol / liter (calculated) to achieve, after dissolution in the diluent, a pH of 6.0 and a ratio of FAC to total Cl of 1.0.

Example 11 Sodium dichloroisocyanurate 2,210 g Adipic acid 1,130 g Sodium bicarbonate 1,036 g Sodium carbonate 0.044 g Succinic acid 3,303 g A microbicidal formulation of the aforementioned composition is useful, after dissolution in twenty-five liters of a diluent having a pH of 7.5 , a total alkalinity of 100 mg / liter as calcium carbonate and a total carbon carbon content of 2.1 mmol / liter (calculated) to achieve, after dissolution in the diluent, a pH of 6.0 and a ratio of FAC to Cl total of 1.0.

Example 12 Sodium dichloroisocyanurate = 2.210 g Adipic acid = 1.130 g Sodium bicarbonate = 1.036 g Sodium carbonate = 0.044 g Succinic acid = 0.428 g A microbicidal formulation of the aforementioned composition is useful, after dissolution in a liter of a diluent having a pH of 7.5, a total alkalinity of 400 mg / liter as calcium carbonate and a total carbon carbon content of 8.5 mmol / liter (calculated) to achieve, after dissolution in the diluent, a pH of 6.0 and a ratio of FAC to total Cl of 1.0.

Example 13 Sodium dichloroisocyanurate = 2.210 g Adipic acid = 1.130 g Sodium bicarbonate = 1.036 g Sodium carbonate = 0.044 g Succinic acid = 0.017 g A microbicidal formulation of the aforementioned composition is useful, after dissolution in a liter of a diluent having a pH of 7.5, a total alkalinity of 100 mg / liter as calcium carbonate and a total carbon carbon content of 2.1 mmol. /liter (calculated) to achieve, after dissolution in the diluent, a pH of 6.0 and a ratio of FAC to total Cl of 1.0. With reference to Examples 7-13, Example 13 is an example of a microbicidal formulation, in which the total alkalinity of the diluent water plays a very small role, since it is necessary to merely add 0.017 g of succinic acid to the adipic acid already present in the microbicidal formulation, with the order to achieve a target dosed pH of 6.0. With respect to Examples 7, 9 and 12, the total alkalinity of the diluting water plays a minor role, since it is necessary to add 0.2 to 0.6, preferably 0.218 to 0.561 g of succinic acid to the adipic acid already present in the microbicidal formulation, with the order to achieve a target dosed pH of 6.0. With respect to Example 8, the total alkalinity of the diluting water plays a medium role, since it is necessary to add 2,619 g of succinic acid to the adipic acid already present in the microbicidal formulation, in order to achieve a target dosed pH of 6.0. With respect to Examples 10 and 11, the total alkalinity of the diluting water plays a greater role, since it is necessary to add 3-15 g, preferably 3,303-13,589 g of succinic acid to the adipic acid already present in the microbicidal formulation, for the purpose to achieve an objective dosed pH of 6.0.

Claims (12)

1. A suitable microbicidal formulation, after dissolution in a diluent to form a microbicidal solution for the microbicidal treatment of an environment, the environment of the group consisting of an external surface or a lumen of an apparatus used in the production, preparation or processing of food or beverages, process liquid and liquid for human or animal consumption, the formulation includes: sufficient diluent neutralizing alkalinity, so that, after dissolution in the diluent, an alkalinity not exceeding 100 is observed mg / liter, preferably not greater than 50 mg / liter of alkalinity per bicarbonate, in the microbicidal solution, the alkalinity neutralizing diluent being an edible acid or its salt or a mixture thereof; sufficient pH neutralizing agent so that, after dissolution in the diluent, a pH of 5.0-8.0, preferably 6.0-6.8 in the microbicidal solution is observed; and a microbicidally effective amount of an alkalinity sensitive microbicidal agent, the available halogen microbicide agent being released, in aqueous solution, from a halogenated isocyanuric compound or a salt thereof, selected from the group consisting of sodium dihaloisocyanurate, dihaloisocyanurate of potassium and trihaloisocyanuric acid; the formulation being adapted to release a microbicidally effective amount of the available halogen in a microbicidally effective time period.

2. A microbicidal formulation according to claim 1, characterized in that the halogenated isocyanuric compound is sodium dichloroisocyanurate.

3. A microbicidal formulation according to claim 1, characterized in that the microbicidally effective amount of the available halogen is released from 1 to 5000 ppm of the halogenated isocyanuric compound or a salt thereof, and the microbicidally effective time period is in the range of 10 seconds to 48 hours.

4. A microbicidal formulation according to any of the preceding claims, characterized in that it is effective against E. coli or Pseudomonas or is a resistant microorganism, still more preferably a thermoduric or thermophilic organism, and even more preferably a microorganism species selected from Bacillus, Micrococcus , Microbacterium, Clostridium, Listeria, Alcaliigenes, Arthrobacter, Lactobacillus, Serratia or any other spore-forming species.

5. A microbicidal formulation according to any of the preceding claims, characterized in that the alkalinity neutralizing diluting agent is succinic acid or a salt thereof.

6. A microbicidal formulation according to any of claims 1 to 5, characterized in that the alkalinity neutralizing diluting agent is citric acid or a salt thereof.

7. A microbicidal formulation according to any of the preceding claims, suitable for dissolution in the diluent, the diluent contains, in total, 2 g of alkalinity as calcium carbonate, characterized the formulation because the diluent neutralizing agent of alkalinity comprises 53.3% (by weight) of the microbicidal formulation.

8. A microbicidal formulation according to any one of claims 1 to 6, suitable for dissolution in the diluent, the diluent containing, in total, 10 g of alkalinity as calcium carbonate, in which the alkalinity-neutralizing diluent comprises 55.7 to 83.1%, preferably 57.4 to 81.7% (by weight) of the microbicidal formulation.

9. A suitable microbicidal formulation, after dissolution in a diluent to form a microbicidal solution for the microbicidal treatment of an environment, the environment of the group consisting of an external surface or a lumen of an apparatus used in the production being selected, preparation or processing of food or beverages, process liquid and liquid for human or animal consumption, the formulation because it comprises: sufficient diluent neutralizing the alkalinity so that, after dissolution in the diluent, an alkalinity is observed greater than 100 mg / liter, preferably not more than 50 mg / liter of alkalinity per bicarbonate in the microbicidal solution, the alkalinity neutralizing diluent being an edible acceptable acid or a salt or a mixture thereof; sufficient pH neutralizing agent so that, after dissolution in the diluent, a pH of 5.0 to 8.0, preferably 6.0 to 6.8, is observed in the microbicidal solution; and a microbicidally effective amount of an alkalinity-sensitive microbicidal agent, the available halogen microbicide agent being released, in aqueous solution, from a halogenated isocyanuric compound or a salt thereof, selected from the group consisting of sodium dihaloisocyanurate, potassium dihaloisocyanurate and trihaloisocyanic acid; a lubricant; the formulation being adapted to release a microbicidally effective amount of the available halogen in a microbicidally effective time period, with the proviso that more than 35% (by weight) of an organic acid is present as the alkalinity neutralizing diluent.

10. A method for optimizing the microbicidal effectiveness of a microbicidal formulation, the formulation for dissolution, in use, in a diluent to form a microbicidal solution, the method comprises the provision of sufficient alkalinity-neutralizing diluent in the microbicidal formulation to observe , after dissolution in the diluent, an alkalinity not higher than 100 mg / liter, preferably not greater than 50 mg / liter of alkalinity per bicarbonate in the microbicidal solution.

11. A microbicidal solution, characterized in that it comprises: a microbicidal formulation in the form of a powder, granulate or tablet, dissolved in a diluent, having the solution: not more than 100 mg / liter, preferably not more than 50 mg / liter of alkalinity per bicarbonate; a pH of 5.0 to 8.0, preferably 6.0 to 6.8; and a microbicidally effective amount of an alkalinity-sensitive microbicidal agent that is available halogen released, in use, from a halogenated isocyanuric compound or a salt thereof, selected from the group consisting of sodium dihaloisocyanurate, potassium dihaloisocyanurate and acid trihaloisocyanuric; the solution being adapted to release the microbicidally effective amount of the microbicidal agent responsive to alkalinity in a microbicidally effective period of time.

12. A microbicidal formulation according to claim 1 or 9, characterized in that the alkalinity neutralizing diluent is an edible organic acid or its salt or a mixture thereof.