Disposable filter for personal protective masks

Abstract

A disposable filter (100) for personal protective masks, comprising: a first outer layer (101) made of a nonwoven fabric layer; a second layer (102) made of polyester fibers positioned below said first layer (101); a third layer (103) comprising a porous activated carbon layer positioned below said second layer (102);a fourth layer (104) consisting of a nonwoven fabric comprising nanocarriers of a liquid formulation configured to transport active agents of plant extracts, therapeutic agents or other active substances to specific sites and having antibacterial and / or antiviral activity; anda fifth layer (105) positioned below said fourth layer (104) and consisting of a closing fabric made of lightweight cotton fibers free from harmful and toxic substances.

Description

[0001] DESCRIPTION

[0002] "Disposable filter for personal protective masks"

[0003] ★ ★ ★

[0004] The present invention relates to a disposable filter for personal protective masks .

[0005] In particular, the present invention relates to a disposable filter for personal protective masks of the type included among personal protective equipment (DDE) .

[0006] As is known, when a virus, such as those responsible for the common cold, influenza or herpes, spreads within the body, it binds to healthy cells, which makes it practically invisible to the immune system. Various devices for protection against viruses are known.

[0007] For example, a first solution is disclosed in patent application CN111685420, which describes a disposable mask using a nanofiber-coated paper-based filtering material and a preparation method for the disposable mask. The disposable mask, which uses the nanofiber-coated paper-based filtering material as an intermediate filtering layer, comprises a surface layer, ear straps connected to the vertical edges of the surface layer of the mask, and a nose bridge clipembedded at the center of the upper edge of the mask. The surface layer of the mask comprises a nonwoven fabric layer, a nanofiber-coated paper-based filtering material layer, and a skin-friendly fabric layer . The outermost layer is made of waterproof material; the innermost layer is made of waterproof and absorbent material; and the intermediate layer is made of nanofiber-coated paper-based filtering material and has the functions of adsorbing and filtering fine particles, viruses and pathogenic microorganisms .

[0008] A second solution is disclosed in patent application CN211747165 (U) , which describes a disposable filtering pad for a mask and a mask comprising the filtering pad. The filtering pad comprises a filtering body adapted to be attached to the face to cover the mouth and nose . The body is made of plant fibers, a rubber profile being symmetrically arranged on the left and right portions of the outer surface of the filtering body, the mask comprising ear hooks . The filtering body adheres to the inner surface of the mask through the rubber profile and the mask is made of nonwoven fabric . Only the filtering pad needs to be replaced as it is disposable, while the mask can be used repeatedly.A third solution is disclosed in patent application CN105249567 (A) , which describes a disposable nonwoven fabric mask. The mask comprises multiple filtering layers, fastening elastics, an inner nonwoven fabric layer, a layer containing traditional Chinese medicine preparations, an antibacterial layer, a layer containing activated carbon, and an outer nonwoven fabric layer . All layers are mutually bonded by means of a hot-melt adhesive so as to form the mask. The layer containing traditional Chinese medicine preparations is immersed in a decoction and subsequently extracted and air-dried. The antibacterial layer is uniformly coated with a layer of titanium dioxide antibacterial agent having a particle size of 100 nm. At least one face of the bactericidal layer is uniformly coated with a titanium dioxide antibacterial coating together with activated carbon or zeolite or bamboo charcoal or a mixture of activated carbon, zeolite and bamboo charcoal . The mask exhibits good antibacterial properties, high adsorption capacity and a refreshing effect .

[0009] A fourth solution is disclosed in patent application CN107625209 (A) , which describes a protective mask against PM 2.5 containing plant essential oil . The protective maskcomprises cotton gauze, a nonwoven fabric layer containing activated carbon, and a plant extract; the cotton gauze comprises three layers; one cotton gauze layer is immersed in Citrus maxima peel extract; the cotton gauze layer impregnated with the extract and the activated carbon layer are arranged between the other two cotton gauze layers . The Citrus maxima peel extract has a positive effect on the humidity of inhaled air and alleviates respiratory system diseases . The filter is easy to replace and has an ideal protective effect against PM 2.5.

[0010] A fifth solution is disclosed in patent application RU2738184, which describes a protective mask with carbon filters usable in medical practice in general for individual respiratory protection against airborne infections . The protective mask with carbon filter comprises a housing with a device for fastening it to the face and a chamber with a filter installed in the front portion of the mask. The filter is made in the form of a blister consisting of a substrate film with integrated activated carbon tablets .

[0011] However, the known protective devices or masks are not completely effective against different types of viruses . Furthermore, they are unable to modulate the inflammatorystate generated during infection, as occurs, for example, with the cytokine storm triggered by SARS-CoV-2 infection . Therefore, they do not inhibit alveolar inflammation nor promote macrophage recruitment at the infection site .

[0012] An obj ect of the present invention is to provide a disposable filter for personal protective masks able of inhibiting various types of microorganisms, in particular the SARS-CoV-2 virus but also other Coronaviruses, Adenoviruses and Rotaviruses .

[0013] Scope of the present invention is also to provide a disposable filter having optimized efficiency and microbial properties .

[0014] The disposable filter according to the invention have an enhanced efficiency and antimicrobial properties, by virtue of the active agents adsorbed on the filter itself . Additional benefits can be obtained, such as suppression of the cytokine storm generated during SARS-CoV-2 infection and, therefore, alveolar inflammation, thereby providing characteristics able to overcome the limitations of the known personal protective devices .According to the present invention, a disposable filter for personal protective masks is provided as defined in claim 1 .

[0015] For a better understanding of the present invention, a preferred embodiment will now be described purely by way of non-limiting example with reference to the accompanying drawings, in which:

[0016] - Figure 1 shows a sectional view of a disposable filter for personal protective masks according to the invention;

[0017] Figure 2 shows a personal protective mask comprising the disposable filter of Figure 1.

[0018] With reference to said figures and, in particular, to Figure 1, a disposable filter 100 for personal protective masks according to the invention is shown.

[0019] In particular, the disposable filter 100 comprises : - a first outer layer 101 made of a thin nonwoven fabric (NWF) layer having PM 2.5 porosity, thus capable of retaining particles having a size larger than or equal to 2.5 microns;- a second layer 102 made of high-performance polyester fiber acting as a filtering mat positioned below the first layer 101 ;

[0020] - a third layer 103 comprising a porous activated carbon layer positioned below the second layer 102 ; - a fourth layer 104 positioned below the third layer 103 and consisting of a nonwoven fabric completely permeated by a liquid formulation of nanocarriers, i . e . nanoparticles adapted to transport therapeutic agents obtained from plant extracts or other active agents to specific sites and having antibacterial and / or antiviral function;

[0021] - a fifth layer 105 positioned below the fourth layer 104 and consisting of a closing fabric made of lightweight cotton fiber which does not irritate the skin and is free from harmful or toxic substances that could otherwise be absorbed during the inhalation phase .

[0022] In use, the fifth layer 105 is configured to be placed in contact with the skin and mouth of a user, whereas the first layer 101 faces outward.As well known, nanoparticle-based formulations are colloidal dispersions consisting of particles (solid or vesicular) suspended in a liquid medium. The composition of such systems is closely related to the physico-chemical properties of the active agents to be delivered, which determine the selection of the most appropriate components and preparation methods . Said definition of liquid nanoparticle formulation is considered in the present invention .

[0023] According to one aspect of the invention, the formulation containing the active agent may be polymeric, lipidic or saccharidic in nature depending on the physicochemical characteristics of the selected substance .

[0024] The active component are delivered by means of delivery systems (carriers) , such as nanoparticles, liposomes or other vectors that are chemically and physically compatible with the substances used in the formulation.

[0025] The delivery systems of said active agents may include nanocarriers and liposomes, also using cyclodextrins as adsorbents of the active principles described elsewhere in this document . Such delivery systems will be loaded into two types of supports . A first type provides the use of naturalfibers (e . g. , cotton) or blended fibers functionalized with delivery systems loaded with the active agent and subsequently lyophilized. Rehydration by means of water vapor originating from the breathing of the subj ect wearing the mask with the filter proposed herein will promote the release of the active agent previously loaded on the filter .

[0026] According to another aspect of the invention, the second type of support provides the use of hydrogels based on chitosan, chitin or other biocompatible polymers selected according to the active agent chosen for preparation of the filter . Also in this case, the support loaded with the selected delivery system and containing the active agent will be dehydrated / lyophilized and will undergo the same rehydration process described above .

[0027] Preferred examples of biocompatible polymers include polyetheretherketone, polyphenylsulfone, polypropylene, ultra-high molecular weight polyethylene and other polymers used for this purpose .

[0028] The formulation intended for the delivery of a given active agent is obtained by means of established and scientifically validated methodologies for its preparation.According to a further aspect of the invention, the disposable filter 100 is adhesive . In particular, the filter 100 comprises an extensible adhesive layer allowing improved adaptation to masks . Indicators in this case are meters for measuring the concentration of volatile compounds .

[0029] The use of humidity indicators placed in a region not affecting the breathing surface of the filter serves to evaluate the amount of water present in the formulation, thereby indicating the end of therapeutic activity.

[0030] The adhesives used to adhere the filter to the mask are conventional adhesives currently authorized and used for medical dressings .

[0031] According to one aspect of the invention, the second layer 102 comprises on its surface elements with small folds and heat-sealed spacers . The heat-sealed spacers may be tested by electronic scanning and supplied with the manufacturer ' s test report in order to certify the data recorded during testing. In particular, certain structural characteristics ensure a maximum operating temperature of 80°C and a maximum operating humidity of 90% .

[0032] Advantageously according to the invention, the porous activated carbon layer of layer 103 absorbs organic moleculesresponsible for unpleasant odors and synergistically promotes the removal of smoke, pollen, mites and bacteria, thereby improving the quality of incoming air, i . e . inhaled air .

[0033] According to one aspect of the invention, layers 101-105 are held together by electromechanical stapling with fusion of the outer edge .

[0034] Advantageously according to the invention, the filter 100 has a progressive density structure increasing from the fifth layer 105 toward the outer layer 101, i . e . toward the side of exhaled air, thereby increasing accumulation capacity while reducing pressure loss across the filter and increasing the service life thereof . In other words, the first outer layer 101 has maximum density while the fifth layer 105 has minimum density.

[0035] According to another aspect of the invention, all materials used are self-extinguishing materials satisfying the fire resistance requirements of Class Fl according to DIN 53438.

[0036] According to one aspect of the invention, the plant-derived extracts, together with other active molecules alsoof synthetic origin, are selected from the group consisting of :

[0037] - beeswax

[0038] - carnauba wax

[0039] - bergamot essential oil

[0040] - cedar essential oil

[0041] - grapefruit oil

[0042] - lemon essential oil

[0043] - sweet orange essential oil

[0044] - bitter orange essential oil

[0045] - mandarin essential oil

[0046] - sweet almond oil

[0047] - essential oils of oregano, thyme and lavender, individually or in any mixture thereof

[0048] - cetylpyridinium chloride

[0049] - glycerin, xanthan gum

[0050] - Cinnamomum zeylanicum, Daucus carota, Eucalyptus globulus and Rosmarinus officinalis essential oils, individually or in any mixture thereof

[0051] - oils of Laurus nobilis, Juniperus oxycedrus ssp .

[0052] oxycedrus, Thuj a orientalis, Cupressus sempervirens ssp . pyramidalis, Pistacia palaestina, Salviaofficinalis and Saturej a thymbra, individually or in any mixture thereof

[0053] - tea tree oil (Melaleuca alternifolia)

[0054] - oleuropein

[0055] - polyphenols .

[0056] In particular, the compounds present in the formulation comprise both derivatives of natural extracts and molecules with specific activity (e . g. cetylpyridinium chloride; range 0.05-10%) . Natural compounds include extracts from the genus Citrus having antimicrobial, antifungal and antiviral activity for active concentrations in the range of 0.1-50%; extracts of medicinal plants (e . g. Salvia officinalis, Laurus nobilis, Rosmarinus officinalis, Eucalyptus globulus, Cinnamonum zeylanicum; range 1-80%) and active compounds and polyphenols extracted from Olea europaea or derived from sweet almond (range 1-50%) .

[0057] Medicinal plants are considered a natural source of biologically active substances (natural active agents) having potential therapeutic and / or preventive properties with respect to various pathological conditions . Many naturally derived molecules have been widely investigated in the scientific literature and by the Applicant throughstudies assessing their specific biological activities, such as antioxidant and antiviral activity.

[0058] According to an aspect of the invention, the filter contains indicators ( for example litmus-paper-type strips) enabling evaluation of the actual duration of the formulation contained therein and allowing the user to replace the filter when it is no longer effective .

[0059] An exemplary embodiment includes an indicator consisting of silica gel, turning green when it has bound the maximum amount of humidity.

[0060] Since the active agents mainly comprise essential oils, which are characterized by aroma and volatile compounds, the effective duration of the formulation is related to the duration of the fragrance, i . e . the concentration of volatile compounds, whose disappearance indicates depletion of the active agent and therefore of the product effectiveness .

[0061] The components contained therein are encapsulated within carriers which open and release the substances through the physical action of heat generated by breathing and through absorption of water contained in the breath.

[0062] The filter may be inserted inside a protective mask, shown in Figure 2 . The present invention further relates toa personal protective mask comprising a disposable filter according to any one of the preceding claims, said filter being configured to release active compounds during inhalation by a user .

[0063] In use, the nanocarriers present in layer 104, upon contact with water vapor generated by breathing, disintegrate and release essential oils that are inhaled by a user wearing a mask including the filter 100, during the inhalation phase .

[0064] Advantageously according to the invention, the essential oils include aromatic molecules capable of disrupting the viral membrane, thereby enabling the immune system of a user to identify viruses, prepare an adequate defense and effectively attack them.

[0065] Furthermore, once they reach the pulmonary alveoli, the essential oils penetrate the bloodstream. When a virus such as those responsible for the common cold, influenza or herpes spreads in the body, it binds to healthy cells, thereby becoming practically invisible to the immune system, but the thousands of nasal receptors rapidly capture nearby essential oil particles, which penetrate the entire respiratory tract— paranasal sinuses, pharynx, larynx,bronchi and lungs— and, in the case of otorhinolaryngological infections, act directly and effectively on the target organism. Moreover, essential oils can control fungal growth or eliminate fungi . Bergamot essential oil, in particular, may also have a positive effect on mood as it induces anxiolytic-like effects without the sedative effect typical of benzodiazepines . As a further example of bioactivity performed by natural compounds, polyphenols such as those from sweet almond and olive leaf extract (OLE) , in particular oleuropein and hydroxytyrosol, exhibit antiviral, antibacterial, anti-inflammatory and antioxidant properties and may reduce the rates of upper respiratory infections (URI ) .

[0066] Therefore, the disposable filter for personal protective masks according to the invention provides broad antimicrobial activity (antibacterial, antiviral and antifungal) .

[0067] Furthermore, the disposable filter for personal protective masks according to the invention, containing a formulation based on natural extracts, provides protective effects against microorganisms and beneficial properties for the organism of the user .Another advantage of the disposable filter for personal protective masks according to the invention is that it is disposable and therefore hygienically and functionally optimized.

[0068] Finally, the disposable filter for personal protective masks according to the invention may be used by subj ects having compromised immune systems or immunosuppressed sub ects .

[0069] It is finally clear that modifications and variations may be made to the disposable filter for personal protective masks according to the invention described and illustrated herein without departing from the scope of protection of the present invention as defined in the appended claims .

Claims

CLAIMSl . A disposable filter ( 100 ) for personal protective masks , comprising :- a first outer layer ( 101 ) made o f a nonwoven fabric layer ;- a second layer ( 102 ) made of polyester fibers acting as a filtering mat positioned below and in contact with said first layer ( 101 ) ; - a third layer ( 103 ) comprising a porous activated carbon layer positioned below and in contact with said second layer ( 102 ) ;- a fourth layer ( 104 ) positioned below and in contact with said third layer ( 103 ) and consisting of a nonwoven fabric comprising nanocarriers of a liquid formulation configured to transport active agents of plant extracts , therapeutic agents or other active substances to speci fic sites and having antibacterial and / or antiviral activity; and - a fi fth layer ( 105 ) positioned below and in contact with said fourth layer ( 104 ) and consisting of a closing fabric made of lightweight cotton fibers free from harmful and toxic substances .

2. Disposable filter ( 100) according to claim 1, wherein said liquid formulation containing an active agent is of polymeric, lipidic or saccharidic nature .

3. Disposable filter ( 100) according to claim 1 or 2, wherein said nanocarriers comprise nanovesicles and / or liposomes loaded within a first type of support and a second type of support .

4. Disposable filter ( 100) according to claim 3, wherein said first type of support comprises lyophilized natural fibers .

5. Disposable filter ( 100) according to claim 3, wherein said second type of support comprises an element selected from the group consisting of chitosan hydrogels, chitin hydrogels and other biocompatible polymers .

6. Disposable adhesive filter ( 100) according to claim 1, further comprising a humidity indicator configured to change from one color to another according to a humidity value .

7. Disposable filter ( 100) according to claim 1, wherein the second layer ( 102 ) comprises on its surface heat-sealed spacers and surface foldsconfigured to improve air distribution and filtration efficiency.

8. Disposable filter ( 100) according to claim 1, wherein the layers ( 101, 102, 103, 104, 105) are joined together by electromechanical stapling with fusion of an outer edge .

9. Disposable filter ( 100) according to claim 1, wherein multilayer structure of the filter has a progressive density increasing from the fifth layer ( 105) toward the outer layer ( 101 ) .

10. Disposable filter ( 100) according to claim 1, comprising plant-derived extracts selected from the group consisting of :- beeswax;- carnauba wax;- bergamot essential oil;- cedar essential oil;- grapefruit oil;- lemon essential oil;- sweet orange essential oil;- bitter orange essential oil;- mandarin essential oil;- sweet almond essential oil;- essential oils of oregano, thyme and lavender, individually or in mixtures thereof ;- cetylpyridinium chloride, glycerin, xanthan gum;- Cinnamomum zeylanicum, Daucus carota, Eucalyptus globulus and Rosmarinus officinalis essential oils, individually or in mixtures thereof ;- oils of Laurus nobilis, Juniperus oxycedrus ssp . oxycedrus, Thuj a orientalis, Cupressus sempervirens ssp . pyramidalis, Pistacia palaestina, Salvia officinalis and Saturej a thymbra, individually or in mixtures thereof ; - tea tree oil (Melaleuca alternifolia) ;- oleuropein;- polyphenols .

11. Disposable filter ( 100) according to claim 1, wherein the active agent comprises :- plant extracts from the genus Citrus and molecules having specific activity in a concentration range of 0.05-10% with active concentrations in the range of 0.1-50%; - extracts of medicinal plants in a concentration range of 1-80%;- essential oils and active compounds extracted from Olea europaea and polyphenols derived from sweet almond in a concentration range of 1-50% .

12. Disposable filter ( 100) according to claim 1, further comprising indicators configured to indicate the effective duration of the formulation contained therein.

13. Disposable filter ( 100) according to claim 1, further comprising an extensible adhesive layer .

14. Disposable filter ( 100) according to claim 1, wherein said first outer layer ( 101 ) is made of nonwoven fabric having PM2 . 5 porosity configured to retain particles having dimensions less than or equal to 2.5 pm.

15. Disposable filter ( 100) according to claim 1, wherein the nanocarriers contained in the fourth layer ( 104 ) are configured to release active agents upon contact with water vapor generated by the breathing of a user .

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