MXPA06009217A - Prolonged deactivation - Google Patents

Abstract

A method of obtaining a prolonged reduction in the allergen loading of an allergen-contaminated inanimate substrate comprises dispersing into an airspace at which the substrate is located an allergen-reducing amount of an allergen-deactivating compound. Preferably the dispersal of the compound into the airspace is as a vapour and aided by heat.

Description

PROLONGED DEACTIVATION 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 the detritus from the mite species Derma tophogoides 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. Others to the problematic ones 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. WO 01/76371 discloses additional de-activators for home dust mite allergens.

SUMMARY OF THE INVENTION According to a first aspect of the present invention there is provided a method for obtaining a prolonged reduction in the allergen load of an inanimate substrate contaminated with allergen, the method comprises dispersing in an air space in which the substrate is located a reducing amount of allergen of an allergen de-activating compound (hereinafter the "de-activator"), in which the reduction after 14 days, and preferably after 28 days is at least as great as the initial reduction . In particular, a method is provided for obtaining a prolonged deactivation of allergens Der fl and Der pl in a contaminated inanimate substrate, the method comprises dispersing in an airspace in which the substrate is located a reducing amount of allergen of a decomposed compound. activator, in which deactivation after 14 days, and preferably after 28 days, is at least as great as the initial reaction.

DETAILED DESCRIPTION OF THE INVENTION It has now been determined that the provision of a 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 this is not the skin or fur / fur 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 discovered that the reduction in the allergen content in said source is long lasting, 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. These also suggest that the action of the de-activator is not merely a masking or attenuation effect. Any of these effects will probably disappear with time. 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. The use of the de-activating noun and the disabling verb in this description indicates that some or all of the sources of allergens in 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. 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 de-activators. 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. Preferably, the dispersion of the des-activator in the airspace is like a vapor. Preferably, the dispersion of the de-activator is achieved by application of heat. Preferably the heat applied to the de-activator can be by the use of an oil burner, a candle or a grill. The use of a grill allows the heat applied to vaporize the deactivator to be controlled in a manner that is not possible with the above methods. Preferably, a grate is used, preferably having a temperature of at least 100 ° C. 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 containing the de-activator and 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 de-activator can be used as such, or it can be comprised within an oil-in-water formulation, or it can be comprised within an oil-in-water emulsion formulation. Any oil / water formulation suitably comprises at least 0.5% by weight of the de-activator (in total, when more than one of said de-activators is used) more preferably at least 2%, and even more preferred at least 6%. Suitably any oil-water formulation comprises up to 25% by weight of the de-activator (in total, when more than one of said de-activators is used), preferably up to 20%, and even more preferred up to 15%. 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 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, Dre Myers , 1992 VCH Publishers, Inc. Nonionic surfactants may be especially suitable. Registered brand name surfactant packages can be used to form emulsions, for example E-Z-MULSE (trade name) a non-ionic surfactant package from Florida Chemical Company, E.Ü.A. 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 allergen deactivating compound is provided to achieve irreversible reduction of a population of allergens. 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 dust is 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 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. An oil burner containing 0.8 ml of ß-pinene floating on 6 ml of distilled water is placed in the cabin and the cabin is sealed. Turn on the oil lamp and let it burn, under the oil / water mixture until all the liquid is vaporized (30 minutes approximately). Then the candle goes out. 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. Two tests are carried out. The test samples are analyzed for the allergen Der pl using an ELISA (enzyme-linked immunosorbent assay) to determine the allergen content. 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. An analysis is performed at week 0 (24 hours after the tests are completed.) Another analysis is performed after 2 weeks The allergen reductions Der pl are as follows: Week 0 - 68.0% Week 2 - 66.3% The statistical analysis suggests that these results may not be separated. Corresponding tests are performed and the same ELISA is performed at week 0 and after 4 weeks. The allergen reductions Der pl are as follows: Week O - 77.5% Week 4 - 91.6% Statistical analysis suggests that the finding of the highest allergen reduction after 4 weeks is statistically significant.

Claims (3)

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. - The use of a reducing amount of allergen of an allergen de-activating cund (hereinafter the "de-activator"), dispersed in an airspace in which an inanimate substrate contaminated with allergen is located, to achieve a Prolonged reduction in substrate allergen loading, characterized in that the reduction after 14 days is at least as great as the initial reduction.

2. The use of a reducing amount of allergen of an allergen de-activating cund (hereinafter the "de-activator"), dispersed in an airspace in which an inanimate substrate contaminated with allergen is located, for achieve a prolonged reduction in substrate allergen loading, characterized in that the reduction after 28 days is at least as great as the initial reduction.

3. The use according to claim 1 or 2, characterized in that the de-activator dispersed in the air space is like a vapor. . - The use according to claim 1 or 2, characterized in that the dispersion of the de-activator dispersed in the air space is achieved by application of heat. 5. The use according to claim 4, characterized in that the heat applied to the de-activator can be by the use of an oil burner, a candle or a grill. 6. The use according to any of the preceding claims, characterized in that the deactivator is dispersed in the air space over a period of at least 30 minutes. 7. The use according to any of the preceding claims, characterized in that the deactivator is selected from: a hydrocarbon of the terpene type; a citrus oil; a mint oil; rosewood oil; jasmine oil; incense; bergamot oil; and lemon grass oil. { Cymbopogon citratus); or a cnent thereof. 8. The use according to any of the preceding claims, characterized in that the deactivator cises a terpene-type hydrocarbon or a cnent thereof. 9. The use according to any of the preceding claims, characterized in that the deactivator cises β-pinene. 10. The use according to any of the preceding claims, characterized in that the deactivator cises orange oil or a cnent thereof.