MXPA01000030A - Treatment of airborne allergens - Google Patents

Abstract

A method of denaturing or deactivating an airborne allergen comprising directing at the airborne source of the allergen liquid droplets from a spray device containing a liquid composition which includes an allergen denaturant or allergen deactivant, the method comprising imparting a unipolar charge to the said liquid droplets by double layer charging during the spraying of the liquid droplets by the spray device, the unipolar charge being at a level such that the said droplets have a charge to mass ratio of at least +/- 1 x 10-4 C/kg.

Description

TREATMENT OF AIR-COATED ALLERGENS The present invention relates to the treatment of allergens carried in air. Several allergens are known to be transported through the air and trigger a reaction in humans. For example, it has been known for a long time that home-made dust can trigger allergic reactions in humans, for example asthma and rhinitis. Since 1928 it was reported that dust mites were the primary source of allergic response, but it was only in the 1960s that researchers realized its importance. It is believed that the feces of house dust mites, Dermatophogoides farinae (known as Der-f) and Der atophagoides pteronyssinus (known as Der-p) trigger the body's immune response, thus causing well-known allergic symptoms. One way to overcome these allergic responses has been to aspirate surfaces such as, for example, carpets, which contain dust mites and their feces thoroughly and frequently, but this requires a lot of time (should be done regularly to ensure a free environment of allergic substances) and depends very much on the efficiency of the vacuum cleaner and filter bag used, for example, microfiltration bags or bags of two layers.

An alternative method for creating an allergen-free environment has been the denaturing of the allergen, for example, by the use of an allergen denaturing agent applied to allergens carried in the air through an aerosol spray device. A device of this type produces an aerosol spray when activated and this spray can be directed to any space to be treated. The allergens to be treated are particles carried in the air and the use of a known aerosol spray device results in a low collision rate between the allergen denaturing agent and the allergens carried in the air. The practical consequence of said low collision rate is that the allergen denaturing agent must be used in a significant amount in order to be effective. Other consequences may exist, for example, in the case in which the aerosol spray composition includes a perfume or a fragrance, the selection of a strong odor or a limited fragrance. * Other allergens that are problematic are the allergens of cat (Feld-d) and cockroach allergens (Bla-g). They can be denatured using an allergen denaturing agent for the specific allergen applied using an aerosol spray device. An aerosol spray type device can be of improved efficiency if the small spray droplets have a higher collision rate with the allergen particles and if the small droplets can humidify the surface of the allergen particles. We have now developed an improved method to denaturalize or deactivate allergens carried in the air. In accordance with the present invention there is provided a method for denaturing or deactivating an allergen carried in the air, said method comprises directing to the source carried in the air of the allergen of small droplets of liquid coming from an atomization device containing a composition liquid comprising an allergen denaturing agent or an allergen deactivator, this method comprises supplying a unipolar charge to said small droplets of liquid by double-layer charging during the spraying of the small droplets of liquid through the atomizing device , the unipolar charge is at a level such that said small drops have a charge to mass ratio of at least +/- 1 x 10 ~ 4 C / kg. It is preferred that the unipolar charge provided to the small droplets of liquid be generated only by the interaction between the liquid within the atomizing device and the atomizing device itself when the liquid is sprayed therefrom. Particularly, it is preferred that the way in which a unipolar charge is provided to the small drops of liquid does not depend, even partially, on the connection of the atomization device to an external device that induces a charge, such as a voltage source relatively high, or an internal device that induces a charge, such as a battery. With such an arrangement, the aerosol atomization device is totally autonomous and therefore suitable both for use in industrial, institutional and domestic situations. Preferably, the atomization device is a domestic pressure atomization device that does not have an electrical circuit but can be operated manually. Typically a device of this type has a capacity within a range of 10 ml to 2000 ml and can be operated manually, or through an automatic drive mechanism. The particularly preferred domestic device is a manual aerosol can. Preferably, therefore, the charge to mass ratio of the small droplets is at least +/- 1 x 10 ~ 4 C / kg and is provided to the small droplets of liquid as a result of the use of a spray device with at least one of the characteristics of the material of the drive device, the size and shape of the orifice of the drive device, the diameter of the dip tube, the characteristics of the valve and the formulation of the denaturing composition of the allergen or deactivation of allergen contained within the aerosol device being selected to achieve said ratio between charge and mass of the small droplets through a double layer charge that provides the unipolar charge to the small droplets during the spraying itself of the small droplets of liquid from the orifice of the aerosol spray device. As a result of the method of the present invention, an active approach towards the allergen particles is obtained by means of the denaturing or deactivating agent which forms part of the aerosol spray. As a result, a real reduction of the allergic responses due to the increase of the precipitation and deactivation of the allergen of its active condition when it is carried in the air is perceived and obtained. This result is achieved due to the unipolar charge provided to the small droplets of liquid from the aerosol spray. This charge has two effects, the individual small droplets are attracted to the allergen particles and, since all the small droplets carry the same charge of polarity, they repel each other. Consequently, there is little or no coalescence of the small droplets and, on the contrary, said droplets tend to disperse to a greater extent than in the case of the small uncharged droplets. In addition, if the repulsion forces from the charge - within the small droplets is greater than the surface tension force of the small droplets, the small charged droplets are fragmented into several small smaller charged droplets (exceeding the Rayleigh limit) . This process continues until the opposing forces equalize or until the small drops have completely evaporated. The allergen particles are normally electrically isolated from their surroundings and typically are at a potential that is the same as the potential of their surroundings. A particle of allergen isolated within a cloud of small droplets of electrically charged liquid therefore probably causes a distortion of the electric field configuration generated by the small droplets in such a way that the attraction of the small droplets on the allergen particle is increased. . In fact the small drops of liquid are attracted by the allergen particles. An example of an allergen denaturing agent is tannic acid whose use is described in US Pat. No. 4, 806,526. Many allergen deactivating agents are specific to the type of allergen powder treated. For example, an effective De-f allergen deactivating agent may not function effectively as an Der-p allergen deactivating agent. Various deactivation agents for the treatment of allergens of Der-f and / or Der-p are described in WO 99/15208. Examples of deactivating agents for Der-f and / or Der-p allergens are cedar oil, hexadecyltrimethylammonium chloride, aluminum chlorohydrate, 1-propoxy-propanol-2, polyquaternium-10, silica gel, propylene glycol alginate, ammonium sulfate, L-ascorbic acid, immobilized tannic acid, chlorhexidine, maleic anhydride, hinoki oil, an AgCl and Ti02 composition, diazolidinylurea, 6-isopropyl-m-cresol, a compound of the formula I a compound of formula II a polymeric dialdehyde containing two or more recurring units of formula II I where n = 2 to 200, urea, cyclodextrin, hydrogenated hops oil, polyvinylpyrrolidone, N-methylpyrrolidone, the anthraquinone sodium salt, potassium thioglycolate or glutaraldehyde. The liquid composition sprayed into the air by use of the aerosol atomizing device is preferably a mixture of water and hydrocarbon, or emulsion, or a liquid that is converted to an emulsion by stirring the atomizing device before use or well during the spraying process. An example of a composition which could be prepared in a form suitable for atomization according to the method of the invention is a composition based on US 4806526. While it is known that all liquid aerosols carry a negative charge or a net positive charge as a result of a double layer charge, or due to the fragmentation of the small drops of liquid, the charge provided to the small drops of the liquid sprayed from standard devices is only of the order of +/- 1 x 10 ~ 8 a 1 x 10-5 C / kg. This invention is based on the combination of various design features of an aerosol spray system in order to increase the liquid loading during spraying from the aerosol spray device. A typical aerosol spray device comprises: 1. An aerosol can containing the composition to be sprayed from the device and a liquid or gaseous impeller; 2 . A dip tube that extends into the can, the top end of the dip tube is connected to a valve; 3. A drive device placed above the valve that can be depressed for the purpose of operating the valve; 4. An insert provided in the drive device comprising an orifice from which the composition is sprayed. The preferred aerosol spray device is described in WO 97/12227. It is possible to provide higher loads to the small droplets of liquid by choosing aspects of the aerosol device including the material, shape and dimensions of the drive device, the drive device insert, the valve and the dip tube and the characteristics of the liquid to be sprayed in such a way that the required level of charge is generated as the liquid is dispersed in the form of small drops. Several characteristics of the aerosol system increase the double-layer loading and the exchange of charge between the liquid formulation and the surfaces of the aerosol system. Such increases are caused by factors that can increase the turbulence of the flow through the system, and increase the frequency and speed of contact between the liquid and the internal surfaces of the container and valve and drive system. By way of example, characteristics of the drive device can be optimized in order to increase the load levels in the sprayed liquid from the container. A small hole in the drive device insert, of a size of 0.45 mm or less, increases the charge levels of the sprayed liquid through the drive device. The choice of material for the drive device can also increase the load levels in the liquid sprayed from the device with material, for example nylon, polyester, acetal, PVC and polypropylene tending to < -JAJ_re LU < -? c ~ - -tt xc j cxu.cj. ero.-the load levels, a large orifice vapor phase tap, for example from about 0.50 mm to 1.0 mm generally provides higher load levels. Changes in product formulation can also affect load levels. A formulation containing a mixture of hydrocarbon and water, or an emulsion of a non-miscible hydrocarbon and water, will provide a higher load to mass ratio when sprayed from the aerosol device than a water alone formulation or a hydrocarbon formulation only. It is preferred that an allergen neutralization composition for use in the present invention contain an oil phase, an aqueous phase, a surfactant, a denaturing or antigen deactivating agent and an impellent. Preferably, the oil phase includes a C 9 -C 2 hydrocarbon preferably present in the composition in an amount of 2 to 10% w / w. Preferably, the surfactant is glyceride oleate or a polyglycerol oleate, preferably present in the composition in an amount of 0.1 to 1.0% w / w. Preferably, the impeller is liquefied petroleum gas (LPG) which is preferably butane, optionally in admixture with propane. The impeller may be present in an amount of 10 to 90% w / w depending on whether the composition is contemplated for spraying in the form of a "wet" composition or in the form of a "dry" composition. In the case of a "wet" composition, the impeller is preferably present in an amount of 20 to 50% w / w, preferably in an amount of 30 to 40% w / w. Small droplets of liquid sprayed from the aerosol spray device will generally have diameters within a range of 5 to 100 micrometers, with a peak of small droplets of approximately 40 micrometers. The liquid that is sprayed from the aerosol spray device may contain a predetermined amount of a particulate material, for example, fumed silica, or a predetermined amount of a volatile material such as, for example, menthol or naphthalene. The method of the present invention, in addition to killing microorganisms, also accelerates the natural process of precipitation of particles carried in the air by indirectly charging the particles, thus enabling a rapid and convenient improvement of the air quality. A can for a typical aerosol spray device is formed of aluminum or of a lacquered or unlacquered tin plate or the like. The drive device insert can be formed, for example, of acetal resin. The lateral opening of the valve stem can typically be in the form of two openings of diameters of 0.51 mm.

The present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic cross section through an aerosol spray apparatus in accordance with the present invention; Figure 2 is a diagrammatic cross section through the valve assembly of the apparatus of Figure 1; Figure 3 is a cross-section through the drive device insert of the assembly illustrated in Figure 2; Figure 4 shows the configuration of the orifice of the spray head shown in Figure 3 when viewed in the direction A; and Figure 5 shows the configuration of the swirl chamber of the spray head shown in Figure 3 when viewed in the direction B. Figure 6 illustrates the method of the invention as described in example 6 with reference to to the precipitation regime of dust particles containing allergens. With reference to Figures 1 and 2, an aerosol atomization device according to the present invention is shown. Said device comprises a can 1, formed of a lacquered or unlacquered tin or aluminum plate or the like in a conventional manner, which defines a reservoir 2 for a liquid 3 having a conductivity such that the small drops of the liquid can carry a proper electrostatic charge. Also within the can is a gas under pressure which is capable of pushing the liquid 3 out of the can 1 through a duct system comprising a dip tube 4 and a valve and a drive device assembly 5. The dip tube 4 includes an end 6 terminating in a peripheral part of the can bottom 1 and another end 7 connected to the tail part 8 of the valve assembly. The tailpiece 8 is fixed through a mounting assembly 9 installed in an opening in the upper part of the can and includes a lower portion 10 defining a tailpiece orifice 11 where the tube end 7 is connected. 4. The tailpiece includes a perforation 12 of a relatively narrow diameter in a lower portion 11 and a relatively wider diameter in its upper portion 13. The valve assembly also includes a rod tube 14 mounted within the bore. 12 of the tailpiece and positioned so that it is axially displaced within the bore 12 due to the action of the spring 15. The rod 14 includes an internal bore 16 having one or more side openings (rod holes) 17 (see Figure 2). The valve assembly includes a drive device 18 having a central bore 19 which houses the valve rod 14 in such a manner that the bore 16 of the rod tube 14 is in communication with the bore 19 of the drive device. A passage 20 in the drive device extending perpendicularly relative to the bore 19 joins the bore 19 with a recess including a post 21 in which a spray head is mounted in the form of an insert 22 including a bore 23 in communication with the passage 20. A ring 24 of elastomeric material is provided between the external surface of the valve stem 14 and, usually, this seal ring closes the side opening 17 in the valve stem 14. The construction of the valve assembly is such that when the actuating device 18 is manually depressed, it pushes the valve rod 14 downwards against the action of the spring 15 as shown in Fig. 2 in such a way that the seal ring 24 already it does not close the side opening 17. In this position, a path is provided from the reservoir 2 to the perforation 23 of the spray head in such a way that the liquid can be pushed, under the pressure of the gas in the can, towards the head of sprayed through a duct system comprising the dip tube 4, the tailpiece bore 12, the valve stem bore 16, the drive device bore 19 and the passage 20. A hole 27 (not shown in Fig. 1) is provided in the wall of the workpiece. glue 8 and constitutes a vapor phase tap so that the gas pressure in the reservoir 2 can act directly on the liquid flowing through the valve assembly. This increases the turbulence of the liquid. It has been found that an increased load is provided if the diameter of the hole 27 is at least 0.76 mm. Preferably, the lateral opening 17 joining the valve stem bore 16 with the tailpiece bore 12 has the shape of two holes, each with a diameter no greater than 0.51 mm in order to increase the generation of load electrostatics. In addition, the diameter of the immersion tube 4 is preferably as small as possible, for example 1.2 mm, in order to increase the load provided to the liquid. Also, the charge generation is increased if the diameter of the tailpiece hole 11 is as small as possible, for example, no more than about 0.64 mm. Referring now to Figure 3, a cross-section through the drive device insert of the apparatus of Figures 1 and 2 is shown on an enlarged scale. For simplicity, the perforation 23 is shown in the form of a single aperture. Cylindrical in this Figure. Without a line However, the perforation 23 preferably has, for example, the configuration illustrated in Figure 4. The apertures in the perforation 23 are indicated by reference numeral 31 and the portions defining the apertures in the perforation are indicated by the reference number 30. The total peripheral length of the portions defining the openings in the drill outlet is indicated by L (in mm) and is the total area of the opening in the drill outlet (in mitr) and the values of L are already indicated in Figure 4. L / a is greater than 8 and this condition is especially suitable for load development since it means an increased contact area between the driving device insert and the liquid running through it. . Many different configurations can be adopted in order to produce a high L / a ratio without reducing the cross-sectional area to a value that would allow only low fluid flow rates. Thus, for example, it is possible to employ driving device insert piercing configurations (i) wherein the piercing outlet comprises a plurality of segment-type openings (with or without a central opening); (ii) where the outlet comprises several openings of the sector type; (iii) where the openings together form an outlet in the form of a grill or grid; (iv) where the exit is generally cross-shaped; (v) where the openings together define an outlet in the form of concentric rings; and combinations of these configurations. Particularly preferred are drive device insert drilling configurations wherein a tongue-like portion protrudes into the liquid flow stream and can be vibrated in this manner. This property of vibration can cause a turbulent flow and improve the separation of electrostatic charge from the double layer, allowing a greater load to move in the volume of the liquid. Referring now to Figure 5, a plan view of a possible configuration of a swirl chamber 35 of the drive device insert 22 is shown. The swirl chamber includes 4 side channels 36 equally spaced and tangential relative to an area central 37 surrounding the perforation 23. In use, the liquid pushed from the reservoir 2 by the gas under pressure travels along the passage 20 and hits the channels 36 in a normal manner with respect to the longitudinal axis of the channels. The positioning of the channels is such that the liquid tends to follow a circular motion before entering the central area 37 and thence towards the perforation 23. As a consequence, the liquid is subjected to a substantial turbulence that increases the electrostatic charge in the liquid.

The following examples illustrate the invention. Example 1 The concentration of allergen (for example Der pl, Der fl, Fel dl or Bla gl) in an artificially created aerosol of dust particles (of domestic origin) was quantified and compared to the configuration after the treatment of the cloud of powder with a charged liquid aerosol containing a neutralizing agent and an identical charged liquid aerosol that contained no neutralizing agent. The dust cloud was generated in a 2.2mJ test chamber by dispersing 2.0 g of house dust with compressed air. 2.0 g of liquid aerosol (either with or without the neutralizing agent) were sprayed into the center of the dust cloud, and air sampling was immediately initiated. The air was sampled at a rate of 18 liters per minute for 5 minutes, through a glass fiber filter paper supported on an inline filter holder (German laboratories) to collect the particles carried in the air. The allergen was eluted from these collection papers in 1 ml of 10% BSA PBS-T (saline buffered with phosphate with 0.05% Tween and 10% bovine serum albumin) overnight. The filter paper was then removed and the remaining solution was centrifuged for 5 minutes at 13 minutes., 000 revolutions per minute. The supernatant, which contained the allergen in solution, was decanted in a clean container. Control measurements were taken by sampling the dust cloud without treating it with liquid free aerosol. A minimum of 5 replicates was carried out for the control and for the treatment with the charged aerosol containing a neutralizing agent and the equivalent aerosol without the neutralizing agent. The concentrations of allergen in the solutions collected were assayed using standard ELISA (Enzyme Linked Immunosorbent Assay) methods. The aerosol formulation containing a neutralizing agent was produced from the following ingredients: Ethyl alcohol (30% volume / volume) Water (59% volume / volume) Benzyl alcohol (10% volume / volume) Á Tidánniiccoo acid (1% weight / volume) The mixture was introduced into a conventional aerosol can. The can was pressurized using compressed air to achieve a pressure of 91,403 kg / m2 (130 psi) inside the can. The level of charge of the small droplets produced from this dew can be artificially raised to a charge to mass ratio of -1 x 10 ~ 4 C / kg by supplying a load of -10 kv to the seam of the can from from a high voltage power source. A flow rate of about 1.5 g / sec was obtained. The small drops were quickly dispersed in the air. The aerosol spray device described above was compared to a standard, known aerosol spray device loaded with the same aerosol formulation. When used to counteract the allergens in a room in accordance with the protocol described above, it was found that the amount of atomization required was significantly less with the device described above in comparison with the use of a known standard device. EXAMPLE 2 The rate of removal of dust particles in an actinically created powder cloud containing a quantified allergen concentration was quantified using an air particle counter (APC 300A, Malvern Instruments, Malvern, UK). The rate of removal that occurs by natural processes alone was compared to the velocity after treatment of the dust cloud with a charged liquid aerosol composition containing an allergen denaturing agent (charge to mass ratio: -1.4 x 10 ~ 4 C / kg "1) sprayed from a hand pump under pressure, and an equivalent liquid spray that was not charged (load to mass ratio -1.3 x 10 ~ 6 C / kg-1). a cloud of dust particles of domestic origin in a 2.2m3 test chamber, by dispersing 2.0 g of powder with compressed air.The concentration of the particles in this cloud over a period of 14 minutes was quantified using the counter particles in the air, and a value was obtained for the natural rate of removal for this powder To quantify the effect of aerosol sprays of charged and uncharged liquids on the concentration of dust particles, s I spray 2.0 g of one of these sprays in the center of the artificial powder cloud, immediately after a first measurement of the particle concentration. Subsequent measurements of the dust concentration reflected the removal of particles that was achieved through the liquid aerosol spray. A minimum of five replications were made for the natural rate of settlement of particles and for the removal caused by the aerosol spray of charged and unloaded liquid. Typical results appear in figure 6 for the percentage of particles of diameters from 1 to 2 microns remaining carried in the air. The speed with which dust particles settle due to natural processes alone was fairly constant and low. Spray aerosols of liquid generated by pressurized manual devices caused the removal of 60% of the particles within a period of 90 seconds. Sprays of charged liquid spray removed almost 90% of the particles within a period of 90 seconds. The improved removal of particles and the denaturation of allergen that are achieved when the liquid aerosol had charge compared to what is obtained through the spray of uncharged liquid was statistically significant (p <; 0.05).

Claims (1)

1. CLAIMS A method for denaturing or deactivating an allergen carried in the air, which comprises directing towards the source of allergen carried in air small drops of liquid coming from an atomization device containing a liquid composition that includes a denaturing agent of allergens or an allergen deactivating agent, the method comprises supplying a unipolar charge to said small droplets of liquid by double-layer loading during the spraying of the small droplets of liquid through the atomizing device, the unipolar charge being found at a level such that said small droplets have a charge to mass ratio of at least +/- 1 x 10 ~ 4 C / kg. A method according to claim 1, wherein the atomizing device is an aerosol atomizing device. A method according to claim 1 or according to claim 2, wherein the liquid composition is an emulsion. A method according to any of the preceding claims, wherein the small drops of liquid have a diameter within a range of 5 to 100 microns. A method according to any of the preceding claims, wherein the composition includes an allergen denaturing or deactivating agent effective against allergens Der f, Der p, Fel d and / or Bla gl. A method according to any of the preceding claims, wherein the unipolar charge is provided to the small drops of liquid only through the interaction between the liquid and the atomization device, without the supply of any charge from an internal device or external load inductor. A method according to claim 6, wherein the ratio between the charge and the mass of the small drops is at least +/- 1 x 10 ~ 4 C / kg and is provided to the small drops of liquid as a result of the use of an aerosol spray device with at least one of the characteristics of the material of the drive device, the size and shape of the orifice of the drive device, the diameter of the dip tube, the characteristics of the valve and the formulation of the allergen denaturation composition or allergen deactivation contained within the aerosol device being selected with the object of achieving said ratio between charge and mass of the small droplets through a double layer charge that provides the unipolar charge to the small drops during the spraying itself of the small droplets of liquid from the orifice of the aerosol spray device. A method according to any one of the preceding claims, wherein the liquid composition comprises an oil phase, an aqueous phase, a surfactant, an allergen denaturing agent or an allergen deactivating agent and an impellent. 9. A method according to claim 8, wherein the oil phase includes a Cg-C? 2 hydrocarbon. 10. A method according to claim 9, wherein the C? -C? 2 hydrocarbon is present in the composition in an amount of 2 to 10% w / w. 11. A method according to any of claims 8 to 10, wherein the surfactant is glyceryl oleate or a polyglycerol oleate. 12. A method according to any of claims 8 to 11, wherein the surfactant is present in the composition in an amount of 0.1 to 1.0% w / w. 13. A method according to any of Claims 8 to 12, wherein the impeller is liquefied petroleum gas or compressed gas. A method according to claim 13, wherein the impellent is present in the composition in an amount of 20 to 50% w / w. A method according to any of the preceding claims, wherein the allergen denaturing agent is tannic acid, examples of deactivating agents for Der-f and / or Der-p allergens are cedar oil, hexadecyltrimethylammonium chloride, aluminum chlorohydrate , 1-propoxy-propanol-2, polyquaternium-10, silica gel, propylene glycol alginate, ammonium sulfate, L-ascorbic acid, immobilized tannic acid, chlorhexidine, maleic anhydride, hinoki oil, an AgCl composition and BOD; , diazolidinylurea, 6-isopropyl-m-cresol, a compound of the formula I a compound of formula II a polymeric dialdehyde containing two or more recurring units of formula III where n = 2 to 200, urea, cyclodextrin, hydrogenated hops oil, polyvinylpyrrolidone, N-methylpyrrolidone, the anthraquinone sodium salt, potassium thioglycolate or glutaraldehyde. SUMMARY OF THE INVENTION A method for denaturing or deactivating an allergen carried in air comprises the administration at the source of the allergen carried in air of small drops of liquid from an atomizing device containing a liquid composition including a denaturing agent of allergen or an allergen deactivating agent, the method comprises supplying a unipolar charge to said small droplets of liquid by double layer loading during the spraying of the small droplets of liquid through the spraying device, the unipolar charge being found at such a level that said small droplets have a charge to mass ratio of at least +/- 1 x 10 ~ 4 C / kg.