MXPA06009216A - Deactivating emulsions - Google Patents

Abstract

A method of deactivating an allergen involves dispersing into an airspace an allergen deactivant, the deactivant being provided in the form of an oil-in-water emulsion comprising at least 8 wt%deactivant. Preferably the deactivant is dispersed into the airspace as a vapour. Preferably the dispersal is aided by heat applied to the emulsion.

Description

DEACTIVATING EMULSIONS FIELD OF THE INVENTION The present invention relates to a method for deactivating dust mite allergens.

BACKGROUND OF THE INVENTION It is known that various allergens trigger a reaction in humans. For example, it has long been known that household dust can trigger allergenic reactions in humans, such as asthma and rhinitis. Since 1928 it has been reported that dust mites in dust are the primary source of the allergenic response, but it was not until the 1960s that researchers appreciated its importance. House dust mites produce debris that causes allergenic reaction in many people. It is believed that the main allergens are detritus from the mite species Dermatophogoides farinae and Dermatophagoides pteronyssinus (the allergens are known as Der fl and Der pl respectively). Debris includes feces as well as residues from body parts of mites. A review is provided in Experimental and Applied Acarology, 10 (1991) p. 167- 186. Other allergens that are problematic include cockroach allergens (especially the cockroach allergen Bla gl), and cat allergens (Fel di). In the case of cat allergens, the fur / fur of the cat and / or its salivary deposits seem to be of significance to induce the allergenic response. WO 99/15208 describes a method for deactivating allergens obtained from the powder mite species D. pteronyssinus and D. farinae, which comprises contacting the allergen with one of the 28 de-activators described. These can be supplied in an airspace by aerosol spray. WO 01/76371 discloses additional de-activators for home dust mite allergens. These can be supplied in an airspace using various methods including the use of heat to vaporize an oil, an ultrasonic jet nebulizer, an ion wind or a candle that incorporates a de-activator. In the case of oil, it can be used as such or it can be floated on water or it can be presented in the form of an oil-in-water emulsion, which usually has up to 5% by weight of the oil.

SUMMARY OF THE INVENTION According to a first aspect of the present invention there is provided a method for deactivating an allergen, the method comprising dispersing in an airspace a de-activating amount of allergen of an allergen de-activating compound (hereinafter the "deactivator"). "), the de-activator is provided in the form of an oil-in-water emulsion comprising at least 8% of a de-activator (de-activator weight / weight of the emulsion), and dispersed in the airspace as a vapor. Preferably, the emulsion comprises at least 9%, and more preferred at least 10% of a deactivator. Preferably, the de-activator used in the method of the present invention is provided in the form of an oil-in-water emulsion comprising up to 25% deactivator, preferably up to 20%, more preferred up to 18% and more preferred even up to 15%. % de-activator. An oil-in-water emulsion especially preferred for use in the method of the present invention comprises 12% of a de-activator. The percentages provided in the above definitions indicate the total de-activator content, when more than one de-activator is present.

DETAILED DESCRIPTION OF THE INVENTION In this description, unless otherwise indicated, a given percentage value for a component indicates the weight of the component expressed as a percentage of the total weight of the emulsion. The use of the de-activating noun and the disabling verb in this description indicate that some or all of the sources of allergens at a site become incapable of evoking an allergenic response in a human, by a method of the present invention. The net result is that the source can be reduced in terms of its allergenic capacity, or its allergenic capacity can be completely eliminated. Preferably, the de-activator is selected from: a terpene-type hydrocarbon; a citrus oil; a mint oil; rosewood oil; jasmine oil; incense; bergamot oil; and lemon grass oil (Cymbopogon citratus). Preferred terpene hydrocarbons include tea tree oil, pinol and ß-pinene. An especially preferred de-activator is a citrus oil, more preferred orange oil. Another especially preferred de-activator is β-pinene. A de-activator can be an ideal compound, an individual compound. Alternatively, a mixture of de-activators can be used together. A de-activator can be part of a combination of compounds, of which not all are deactivators. For example, a citrus oil is a mixture of compounds of which not all function as de-activators. Suitably, a de-activator can be dispersed in the airspace over an extended period, for example at least 30 minutes, and preferably at least 1 hour. Appropriately, a de-activator can be dispersed in the airspace on two occasions, interrupted by a period in which there is no dispersion of the de-activator. A de-activator may be dispersed in the airspace on one or more additional occasions, after a corresponding period or periods of non-dispersion of de-activator. Preferably each of said scattering occasions involves the dispersion of de-activator over an extended period, as described above. Preferably the or each period in which there is no de-activator dispersion is an extended period, for example at least 2 hours, preferably at least 4 hours, and even more preferred at least 8 hours. It has been found that the method produces a prolonged reduction in the allergen load of an inanimate substrate contaminated with allergen. The supply of the de-activator in airspace in the manner described causes a permanent reduction in the population of allergens in an inanimate test source. By the phrase "source of inanimate test" is meant a source of evidence which by itself is inanimate (for example it is not the skin or fur / hair of a living animal) and does not contain living organisms, such as dust mites. Dust mite populations may make it difficult to interpret any result. It has been found that the reduction in the allergen content in said source is of long duration, for example at least 7 days, typically at least 14 days, and ideally at least 28 days. Indeed, in tests carried out over a period of 28 days, it has been discovered that the allergen content may continue to decline over time, even when the de-activator has been used days or weeks before. The results suggest that the allergenic species have actually been denatured or degraded, to the extent that, in the first place, they can no longer be formed, and secondly, their degradation products by themselves are not allergenic. This also suggests that the action of the de-activator is not merely a masking or attenuation effect. Any of these effects will probably disappear with time. The formation of emulsions is generally well known in the art and is described, for example, in Modern Aspects of Emulsion Science, edited by Bernard P. Binks, The Royal Society of Chemistry, 1998 and Surfactant Science and Technology, second edition, Drew Myers , 1992 VCH Publishers, Inc. Nonionic surfactants may be especially suitable. Branded surfactant packages can be used to form emulsions, for example E-Z-MULSE (trade name) a nonionic surfactant package from Florida Chemical Company, E.U.A. Preferably, the de-activator is dispersed in the air space as a vapor. Preferably, the dispersion of the de-activator is achieved by the aid of heat applied to the emulsion. Preferably a heat source is placed under a source of the emulsion. This can be, for example, an oil burner, a candle or an electric heat source, such as a grill. Preferably, this is a grate that preferably has a temperature of at least 100 ° C. The use of a grill allows the applied heat to vaporize the de-activator to be controlled, in a way that is not possible with the above methods. This work suggests that the use of a grill below 100 ° C provides some allergen deactivation activity but that the use of a higher temperature provides allergen de-activation activity of a substantial and surprisingly higher level, even when the amount of dispersed de-activator is the same in each case. Preferably the grill has an electric heat source. Preferably, the container and the grill are in contact face to face. Preferably, the grill has a flat surface and the container has a flat base, and the container rests on the grill. Preferably, the container has an opening in its upper region. Preferably, it has a fully open upper face. Preferably, therefore, the container has a flat base, one side (if cylindrical) or sides that depend in ascending fashion therefrom, and no additional side. Preferably, the grill is at a temperature of at least 130 ° C. Preferably, the grate is at a temperature of up to 300 ° C, preferably up to 250 ° C. The present invention involves the dispersion of an allergen de-activator in an airspace. It is possible that allergens transported by air can be deactivated, but it is believed that there is an effective deactivation of allergens transported on surfaces within the airspace. In accordance with a further aspect of the present invention the use of an oil-in-water emulsion is provided to deactivate an allergen at a site, the emulsion comprises 10-15% of an allergen de-activator, a heat source that is used to accelerate the vaporization of the de-activator. In accordance with a further aspect, an oil-in-water emulsion for allergen deactivation comprising at least 8% of a volatile de-activator is provided, in which the de-activator is selected from: a terpene-type hydrocarbon; a citrus oil; a mint oil; rosewood oil; jasmine oil; incense; bergamot oil; and lemon grass oil. Preferably a deactivated allergen in a method or use according to the present invention is a material that evokes an allergenic reaction in a human. For example, this can be an allergen that arises from house dust mites, or from pets. More preferably, the method or use of this invention can deactivate, partially or completely, an allergen arising from the mite species Dermatophogoides farinae (known as Der fl) or, especially from the mite species Dermatophagoides pteronyssinus - (known as Der pl). You can also deactivate cat allergens (Fel di) and cockroach allergens (Bla gl).

EXAMPLES The present invention is further described with reference to the following examples.

Experimental protocol When domestic mites are used for allergen denaturing tests, an inherent difficulty is the variability of the amount of allergen in each small sample, even when taken from the same dust deposit. The amount of powder in the pretreatment sample must be calculated accurately in order to determine the degree of any allergen denaturation. In these tests, the powder sample is applied to the test exposure surface and then one half of this surface powder is removed to measure the control pre-treatment allergen level of said specific sample. Each control is directly relevant to each sample, which provides the best possible calculation of the level of allergen in the sample before exposure to the possible denaturant. All tests employ a glass-reinforced plastic cabin of 0.7 m x 0.7 m x 1.0 m in size. Average values are indicated. All of the following examples measure the reduction of the allergen Der pl from the domestic dust mite Dermatophagoides pteronyssinus. Domestic dust is passed through a number of sieves and the fraction smaller than 53 μm is collected. 0.025 g of powder is placed in a small sieve to distribute it evenly over the test surface.

The test surface is a metal tray lined with PTFE (polytetrafluoroethylene - registered trademark TEFLON) of 30 cm x 30 cm in size. The powder is applied to the tray by moving the sieve continuously over the surface while gently tapping the sieve. One half of the powder is then removed by suction in a line filter and the weight recorded, this is the pre-treatment control. The tray is then placed in the cabin. Candle holders are placed for tea table (tea light holders) - cylindrical containers open upwards (40 mm in diameter, 15 mm high) made to contain lamps (nightlight candles) - each containing 6 ml of water and 0.8 ml of Orange oil - placed together on an electric grill set at 250 ° C. In practice it has been found that this means that the grill temperature is cycled between 130 ° C and 250 ° C. The cabin is sealed. Heat is supplied during the period specified below, and then the grill is allowed to cool. After 24 hours the tray is removed, the dust is collected from it and its weight recorded. The cabin is washed with strong detergent between tests. They perform identical tests that differ only in their test liquids. These are: 5% orange oil that is floated on water (evaporated in 29 minutes) - comparative 12% orange oil that is floated on water (evaporated in 30 minutes) - comparative 20% orange oil that is floated on water (evaporated in 20 minutes) - comparative 50% orange oil that is floated on water (evaporated in 20 minutes) - comparative 12% orange / water oil emulsified with EZ-MULSE - of the invention (the heating stops after 105 minutes; it does not evaporate to dryness. It is believed that this is due to the remaining non-volatile surfactant from the constituent E-Z-MULSE). The test samples are analyzed for the allergen Der pl using an ELISA (test with in-sorbent ligated to enzyme) to determine the content of allergen. This is then related to the weight of the powder that is present in each sample. All samples are multiplied to compare the amount of allergen that is expected to be present in a 0.1 gram sample of powder sample. Then the difference in percentage between the control sample and the exposed sample is obtained. The allergen reductions Der pl are as follows: 5% orange oil in water - 11.9% 12% orange oil in water - 75.4% 20% orange oil in water - 67.0% 50% orange oil in water - 68.1% 12% orange oil in emulsion - 91.0% The non-volatility of the surfactant content of the emulsion suggests that orange oil, in the form of an emulsion, is responsible for the increase in activity, not the content of surfactant per se. It has been found that the allergen content does not recover substantially with the passage of time. The statistical analysis suggests that the increase in activity, from the test liquid of 12% oil in water to the 12% emulsion, is a significant result.

Claims (9)

NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and therefore the content of the following is claimed as property: CLAIMS

1. - A method for deactivating an allergen from the mite species Der fl or Der pl, the method comprising dispersing in an airspace an amount for deactivating the allergen of an allergen deactivating compound (hereinafter the "deactivator"), the de-activator is provided in the form of an oil-in-water emulsion comprising at least 8% of a de-activator (de-activator weight / weight of the emulsion), and dispersed in the airspace as a vapor.

2. - A method according to claim 1, characterized in that the de-activator is dispersed in the air space through a period of at least 30 minutes.

3. - A method according to claim 1 or 2, characterized in that the dispersion is achieved by the help of heat applied to the emulsion.

4. - A method according to any of the preceding claims, characterized in that the de-activator is selected from: a terpene-type hydrocarbon; a citrus oil; a mint oil; rosewood oil; jasmine oil; incense; bergamot oil; Lemon grass oil (Cymbopogon citratus); or a component thereof.

5. - A method according to any of the preceding claims, characterized in that the de-activator comprises a terpene-type hydrocarbon.

6. A method according to any of the preceding claims, characterized in that the de-activator comprises β-pinene.

7. - A method according to any of the preceding claims, characterized in that the de-activator comprises orange oil or a component thereof.

8. The use of an oil-in-water emulsion to deactivate an allergen in a site, the emulsion comprises an allergen de-activator present in a concentration of 10-15% w / w of the emulsion, a heat source that is used to accelerate the vaporization of the de-activator.

9. An oil-in-water emulsion for allergen deactivation comprising at least 8% of a volatile de-activator (weight of de-activator / weight of the emulsion), characterized in that the de-activator is selected from: a mint oil; rosewood oil; jasmine oil; incense; bergamot oil; lemon grass oil; or a component thereof.