POLYMERIC COMPOSITIONS FOR INTRANASAL ADMINISTRATION

TECHNICAL FIELD

[0001] Disclosed are dry powder compositions for intranasal administration a polymeric agent capable of forming a bio-adhesive film upon intranasal administration methods for their preparation and uses thereof in medical and biological methods of prevention and treatment of various conditions.

BACKGROUND Intranasal drug delivery Viral infections

[0002] The respiratory tract is the most common route of viral entry, a consequence of the exposed mucosal surface and the resting ventilation rate of 6 liters of air per minute. The huge absorptive area of the human lung (140 square meters) also plays a role. Large numbers of foreign particles and aerosolized droplets - often containing bacteria, allergens and virions - are introduced into the respiratory tract incessantly. There are several defense mechanisms that protect the respiratory tract from infection by penetrating foreign bodies. For example, protection can be afforded by mechanical barriers -the respiratory tract is lined with a mucociliary layer comprising ciliated cells, mucus-secreting goblet cells, and subepithelial mucus-secreting glands. Foreign particles that enter the nasal cavity or upper respiratory tract are trapped in mucus and carried to the back of the throat, where they are swallowed. If particles reach the lower respiratory tract, they may also be trapped in mucus, which is then brought up and out of the lungs by ciliary action. The lowest reached alveoli are devoid of cilia, however, these gas-exchanging sacs are endowed with macrophages, whose function it is to ingest and destroy particles. Therefore, straightening of the mechanical barrier within the nasal cavity can provide improved protection of the upper respiratory tract from pathogens penetration.

[0003] Intranasal administration is known to be an efficient non-invasive method for systemic delivery of active agent, rapidly achieving effective relevant concentrations in the bloodstream, with no first-pass metabolism, and ease of administration. [0004] The intranasal delivery of drugs utilizes devices of several types, such as nebulizers, pressurized devices, dry powder sprayers, and bi-directional nasal devices, for administration of single metered dose or multiple metered doses of an active agent. [0005] Dry powders are used in intranasal drug delivery due to many advantages of using this dosage form including the improved stability, administration of larger doses and lack of microbial growth. The administration of intranasal powders may improve patient compliance, especially where the smell and taste of the delivered composition comprising excipients is unpleasant. Compared to drug solutions, the administration of powders can result in a prolonged contact with the nasal mucosa. Powder form is suitable for delivery of both small molecules and biologicals, especially peptides, hormones and antibodies.

[0006] WO2019/038756 describes a pharmaceutical composition in a form of dry powder for intranasal administration of various pharmaceutically active agents, the composition comprising two types of solid particles.

Allergies

[0007] Allergic rhinitis (AR) is characterized by sneezing, nasal congestion, nasal itching and rhinorrhea (nasal discharge) and is caused by immunoglobulin E (IgE)- mediated reactions to inhaled allergens. These immune reactions involve mucosal inflammation that is driven by type 2 cells [Bousquet, J., et al Nat Rev Dis Primers 6, 95 (2020); Greiner, A. N., et al., Lancet 378, 2112-2122 (2011)]. AR seems to be the consequence of environmental exposures acting on a predisposed genetic background. AR is often co-morbid with asthma and/or conjunctivitis. AR is a global health problem that causes major burden and disability worldwide.

[0008] Current therapy includes allergen avoidance, pharmacotherapy with Hi- antihistamines or intranasal corticosteroids (INCS) and allergen-specific immunotherapy (AIT). Many patients are dissatisfied with their treatment, for example, because management does not take the patient’s needs into consideration, no cure is available, adherence to long-term therapy is poor and/or because the patient does not fully understand the condition.

[0009] The compositions disclosed herein can be effectively used for treatment and prevention of airways allergies, specifically allergic rhinitis.

Sinusitis [0010] Sinusitis affects about 1 in 8 adults in the United States, resulting in more than 30 million annual diagnoses. It incurs vast costs of managing acute and chronic sinusitis, with additional expenses emanating from lost productivity, reduced job effectiveness, and impaired quality of life. The vast majority of sinusitis cases are viral or non-infectious in origin, although some can be attributed to bacterial infections. Symptoms or signs of ARS are mainly purulent nasal drainage accompanied by nasal obstruction, facial pain/pressure/fullness, or both. When symptoms persist without evidence of improvement for over 10 days beyond the onset of upper respiratory symptoms or worsen within 10 days after an initial improvement (double worsening), there is likelihood of bacterial infection. Most cases of acute rhinosinusitis caused by viral infections are associated with common cold, specifically rhinovirus, adenovirus, influenza vims, and parainfluenza vims infection.

[0011] Of note all these respiratory viruses are extremely sensitive to the creation of local hostile microenvironment in the nasal cavity. The most common bacterial organisms in community-acquired acute bacterial rhinosinusitis are Streptococcus pneumoniae Haemophilus influenzae , Staphylococcus aureus, and Moraxella catarrhalis. The compositions disclosed herein can be effectively used for treatment and prevention of mild and acute viral and bacterial rhinosinusitis.

SUMMARY OF THE INVENTION

[0012] The present disclosure relates to a composition in the form of dry powder for intranasal administration, said composition comprising first type particles, being essentially spherical solid particles comprising at least one physiologically acceptable mucoadhesive polymer and/or bioadhesive polymer and/or gel-forming polymer in combination with at least one functional additive, wherein the size of at least about 90% of said first type particles is about 10-300 microns, wherein the size of at least 50% of the particles is about 30-100 microns and less than about 10% of said first type particles are of size of about 5-30, specifically less than 5 microns.

[0013] The presently disclosed composition can optionally further comprise second type particles being irregularly shaped solid particles comprising at least a pharmaceutically or physiologically acceptable inert carrier, wherein said second type particles are of a mean particle size greater than that of the said first type particles, preferably a mean particle size of from about 50 to about 200 microns. [0014] In embodiments of the disclosed composition, the said composition can be substantially free of excipients other than said at least one functional additive comprised in said first type particles, and said second type particles can be only carrier or carrier with other excipient/s.

[0015] The mucoadhesive polymer and/or the bioadhesive polymer comprised in the presently disclosed composition can be a hydrophilic or amphiphilic gel-forming polymer. Specific examples of the mucoadhesive polymer and/or bioadhesive and/or gel-forming polymer comprised in the disclosed composition are, but not limited to hydroxypropylmethyl cellulose (HPMC, hypromellose), hydroxypropyl cellulose (HPC), sodium carboxymethyl cellulose (CMC), a natural gum such a xanthan gum, guar gum, gum acacia and gum tragacanth, starch, such as maize starch, potato starch, chitosan, algal sulfated polysaccharides, a hydrophilic methacrylic polymer, such a hydroxyethyl methacrylic polymer, or hydrophilic acrylic acid polymers such as Carbopol, polyethylene glycol, Poloxamer, polyvinyl alcohol and any co-polymer, grafted polymer and/or any mixture of at least two thereof. In more specific embodiments said mucoadhesive and/or bioadhesive polymer is hydroxypropyl-methyl cellulose (HPMC).

[0016] In embodiments of the compositions of the present disclosure the functional additive is a physiologically acceptable pH modifying agent. The pH modifying agent can an acidifying agent, specifically an acidifying agent which following intranasal administration and dissolution of the particles, provides the nasal cavity environment with a pH equal to or lower or higher than about 3.5, especially in the range of 3-4. Specific examples are, but not limited to, any one of L-pyroglutamic acid (PCA); ascorbic acid, citric acid, phytic acid, succinic acid, acetic acid, citric acid, hydrochloric acid, lactic acid, tartaric acid, malic acid, salts thereof hydrates, such as mono-, di- or tri-hydrates and anhydrates or monohydrate thereof.

[0017] In other specific embodiments of the composition of present disclosure, where present, the pH modifying agent is an alkalinizing agent, specifically an alkalinizing agent which following intranasal administration and dissolution of the particles, provides the nasal cavity environment with a pH higher than about 8. Specific examples are, but not limited to any one of sodium bicarbonate, sodium hydroxide, potassium hydroxide, monobasic potassium phosphate/ sodium hydroxide solution providing pH 8; dibasic potassium phosphate; dibasic sodium phosphate; alkaline borate buffer comprised from boric acid and sodium hydroxide, potassium citrate, calcium carbonate, sodium lactate and calcium acetate and hydrates and anhydrates thereof.

[0018] In some embodiments of the composition of the present disclosure further comprises at least one physiologically acceptable functional agent, which can be any one of antimicrobial agent, preserving agent, antiseptic agent, disinfectant, solubilizing agent, wetting agent or any mixture of at least two thereof. Specific examples are, but not limited to any one of benzalkonium chloride, benzoic acid, chlorocresol, diazolidinyl urea, imidurea, edetic acid and its salts, potassium sorbate, sorbic acid and its salts, benzethonium chloride or docusate sodium.

[0019] In embodiments of the presently disclosed subject matter, in the disclosed composition the ratio between said at least one muco-adhesive and/or bio-adhesive polymer and said at least one functional additive in said first type particles is between about 90.0-99.99 % w/w.

[0020] Where present, said carrier can be any one of lactose monohydrate, lactose, a lactose functional analogue, or any mixture of at least two thereof. Alternatively, said carrier can be any one of dextrose, sorbitol, mannitol, ma!tito! and xylitol, a cellulose or cellulose derivative, or starch or starch derivative.

[0021] In all aspects and embodiments of the present disclosure the disclosed composition can further optionally comprise at least one pharmaceutical, alimentary or cosmetic scenting agent or fragrance. The said scenting agent or fragrance can be comprised in at least one of said first type particles, in said second type particles or in said dry powder.

[0022] The said scenting agent or fragrance can be, but is not limited to, at least one of a fruit-like scent, a flowery or plant scent, a food-like scent, a beverage-like scent or a perfume-like scent, which can be natural (obtained by various isolation/extraction processes, or they are synthetic. A fruit-like scent can be, for example, apple, banana, citrus, berry, almond scent, or others. A flowery or plant scent can be for example a rose, lily, hibiscus, eucalyptus, mint, spearmint, rosemary, ginger, sage, pepper, lavender, cinnamon, vanilla scent or the like, in the form of extract or oil of the plant, for example eucalyptus oil. A food-like scent can be, for example, candy scent, chocolate scent, honey scent or the like. A beverage-like scent can be, for example, coffee scent or the like.

[0023] The weight ratio between said first type particles and said second type particles, where present is from about 100:1 to about 1:10. Thus, in such compositions, the said first type particles can constitute from about 99.99 % to about 10% of the composition.

[0024] In all aspects and embodiments of the present disclosure, following intranasal administration to a subject of a composition according to the present disclosure, homogeneous distribution and dissolution within the nasal cavity of the subject, the composition forms a protective polymeric film layer adhered to or a polymeric gel layer deposited on the nasal mucosa of said subject, which film layer or gel layer prevents at least in part foreign particulate bodies such as viral pathogens or allergens from accessing the nasal epithelium or penetrating the body of the subject. The particulate bodies can be of a mean size of from about 0.02 to about 20 microns, such as from about 0.3 to about 1 micron, from about 0.02 to about 0.3, 0.3 to about 2 micron, or from about 0.3 to about 3 microns, such as from about 0.3, 0.4, 0.5, 1.0,

1.5, 2.0, 2.5 to about 3.0 microns, about 4.0, 5.0, 10, 15 or 20 microns, and any ranges in between.

[0025] In some embodiments the foreign particles can be viral pathogens or fragments thereof, bacteria or microbial pathogens, or airborne drops or droplets of expelled nasal or oral fluids or liquids, for example of humans carrying viral or bacterial pathogens in the oral cavity or mouth. In other embodiments the foreign bodies can be various air borne or other allergens.

[0026] In some embodiments, the said viral pathogen is a virus of any one of the Coronaviridae including SARS-CoV-2 (CoVID-19), Severe Acute Respiratory Syndrome virus (SARS-CoV) and Middle East Respiratory Syndrome (MERS), Orthomyxoviridae , such as any of Influenza virus type A, Influenza virus type B or Influenza virus type C or any subtype or reassortant thereof including swine Influenza type A virus subtype H1N1 and avian Influenza type A virus subtype H5N1, Filoviridae , such as Marburg virus (MARV) and Ebola virus (EBOV), Flaviviridae such as Zika virus (ZIKV), West Nile virus (WNV), Dengue virus (DENV) and Yellow Fever virus (YFV) or Poxviridae families, and sub-families thereof. In specific embodiments, wherein said virus is SARS-CoV-2.

[0027] In specific embodiments, the present disclosure provides a composition in the form of dry powder for intranasal administration to a subject in need, said composition comprising a first type of essentially spherical solid particles comprising HPMC in combination with a physiologically acceptable pH modifying agent, such as an acidifying agent or an alkalinizing agent, wherein the size of at least about 90% of said first type particles is about 10-300 microns, wherein the size of at least 50% of the particles is about 30-100 microns and less than about 10% of said first type particles are of size of about 5-30, specifically less than 5 microns.

[0028] In specific embodiments, the present disclosure provides a composition in the form of dry powder for intranasal administration to a subject in need, said composition comprising a first type of essentially spherical solid particles comprising HPMC in combination with a physiologically acceptable pH modifying agent, such as an acidifying agent or an alkalinizing agent, wherein the mean size of at least about 90% of said first type particles is about 40-150 microns, wherein the size of at least 50% of the particles are of a mean particle size of about 15-100 microns and less than about 10% of said first type particles are of a mean particle size of about 5-30, specifically less than 5 microns, providing a metered effective nominal dose of said HPMC, wherein following intranasal administration to said subject and dissolution in the nasal cavity of said subject, said composition forms a protective polymeric film layer or gel layer on the nasal mucosa.

[0029] The said film layer or gel layer prevents at least in part foreign particulate bodies of a size of about 0.02 to about 20 micron such as viral pathogens, bacterial pathogens and/or allergens from accessing the nasal epithelium or penetrating the body of the subject.

[0030] Also in these specific embodiments, the said physiologically acceptable pH modifying agent can be an acidifying agent, for example, but not limited to any one of L-pyroglutamic acid (PCA); ascorbic acid, citric acid, phytic acid, succinic acid, acetic acid, citric acid, hydrochloric acid, lactic acid, tartaric acid, malic acid, salts thereof and hydrates and anhydrates thereof, and any mixture of at least two thereof, for example a mixture of citric acid and sodium citrate. Alternatively, said physiologically acceptable pH modifying agent can be an alkalinizing agent being any one of is any one of sodium bicarbonate, sodium hydroxide, potassium hydroxide, monobasic potassium phosphate/ sodium hydroxide solution providing pH 8; dibasic potassium phosphate; dibasic sodium phosphate; alkaline borate buffer comprised from boric acid and sodium hydroxide, potassium citrate, calcium carbonate, sodium lactate and calcium acetate and hydrates and anhydrates thereof and any mixture of at least two thereof but not limited thereto. In these compositions the ratio between said at least one mucoadhesive and/or bioadhesive polymer and said at least one functional additive in said first type particles can be between about 90.0-99.99 % w/w of the polymer, such as 90, 91, 92, 93, 94, 95, 96, 97, 98, 99 to 99.99 % w/w of the polymer, but not limited thereto. For example, in specific embodiments, a composition in accordance with the present disclosure comprises about 80-95% w/w of the polymer, and 20-5% w/w of the functional additive, respectively. By way of a non-limiting example, a specific composition comprises about 90% w/w of HPMC as the polymer and about 10% w/w of a functional additive comprising a mixture of citric acid and sodium citrate, and optionally further additives or excipients.

[0031] In other embodiments of the present disclosure the said functional agent can be any one of a physiologically acceptable antimicrobial agent, preserving agent, antiseptic agent, disinfectant, solubilizing agent, wetting agent or any mixture of at least two thereof. Specific examples are, but not limited to any one of benzalkonium chloride, ADBAC, benzoic acid, chlorocresol, diazolidinyl urea, imidurea, edetic acid and its salts, potassium sorbate, sorbic acid and its salts, benzethonium chloride or docusate, and any mixture of at least two thereof.

[0032] In a specific aspect of the composition of the present disclosure, the functional additive can be a mixture of said at least one pH modifying agent with said at least one physiologically acceptable functional agent, such as but not limited to an antibacterial agent and/or a physiologically acceptable preserving agent (the combination of the functional additive and the functional agent may also be referred to herein as "a mixed functional additive"). A specific non-limiting example of a mixed functional additive is a mixture of at least one said pH modifying agent and at least one said antibacterial agent or preserving agent. In a specific embodiment such mixed functional additive comprises a mixture of citric acid and sodium citrate (as a pH acidic modifying agent) and benzalkonium chloride as an antibacterial/preserving agent, where the benzalkonium chloride may also serve as a surfactant. By way of a nonlimiting example, a specific composition comprises about 85-90% w/w of HPMC as the polymer, about 10-15% w/w of a functional additive comprising a mixture of citric acid and sodium citrate, and about 1-2% of benzalkonium chloride, and can optionally comprise minimal amount of a scenting agent, a flavoring agent and the like, referred to below.

[0033] In all said aspects and specific embodiments of the present disclosure, the disclosed composition can further optionally comprise second type particles being irregularly shaped solid particles comprising at least a physiologically acceptable carrier, wherein said second type particles are of a mean particle size greater than that of the said first type particles, preferably a mean particle size of from about 50 to about 200 microns. The carrier can be any one of lactose monohydrate, lactose, a lactose functional analogue, or any mixture of at least two thereof. Alternatively, carrier can be any one of dextrose, sorbitol, mannitol, maltitol and xylitol, a cellulose or cellulose derivative, or starch or starch derivative. The weight ratio between said first type particles and said second type particles, where present is from about 100:1 to about 1:10, and any ratio within said range. Thus, in such compositions, the said first type particles can constitute from about 99.99 % to about 10% of the composition.

[0034] In all aspects and embodiments of the present disclosure the viral pathogen can be a virus of any one of the Coronaviridae including SARS-CoV-2, Severe Acute Respiratory Syndrome virus (SARS-CoV) and Middle East Respiratory Syndrome (MERE), Orthomyxoviridae, such as any of Influenza virus type A, Influenza virus type B or Influenza virus type C or any subtype or reassortant thereof including swine Influenza type A virus subtype H1N1 and avian Influenza type A virus subtype H5N1, Filoviridae , such as Marburg virus (MARV) and Ebola virus (EBOV), Flaviviridae such as Zika virus (ZIKV), West Nile virus (WNV), Dengue virus (DENV) and Yellow Fever virus (YFV) or Poxviridae families, and sub-families thereof. In specific embodiments said virus is SARS-CoV-2, causing CoVID-19. A "virus" as used herein is to be taken to mean also “virion” and any infectious fragments and particles of the virus/virion. The particulate foreign viral pathogen bodies can be of a mean size of from about 0.02 to about 0.5 microns, such 0.02, 0.03, 0.04, 0.05, 0.1, 0.2, 0.3, 0.4 or 0.5 or any range in between. Published data have suggested that sneezing may produce as many as 40,000 droplets of between 0.5-12 pm in diameter, that may carry millions of pathogens. The droplets with below one micron size can survive indoor as an aerosol for a relatively long time.

[0035] The disclosed compositions can be used in preventing at least in part foreign particulate bodies alone or in air-borne droplets such as viral pathogens, bacterial pathogens or allergens from accessing nasal epithelium or penetrating the body of the subject.

[0036] The effective dose of a composition according to the invention can be from about 0.01 mg to 20 mg, for example 0.01, 0.02, 0.03, 0.4, 0.05, 0.075, 0.1. 0.15. 0.2. 0.3. 0.4, 0.5, 0.75, 1.0, 1.25. 1.5, 2.0, 3.0, 4.0, 5.0. 7.5. 10, 12.5, 15. 17.5 or 20 mg, and any ranges in between, such as 0.01-0.1, 0.1-0.5, 0.5-1, 1-2.5, 2.5-5, 5-10, 10-15 or 15- 20 mg. [0037] The disclosed compositions can be designed for from one to six daily intranasal administrations, for example once, twice, three, four, five or six times daily, for example 1-2, 1-3, 1-4, 1-5, 1-6, 2-3, 2-4, 2-5, 2-6, 3-4, 3-5 or 3-6 daily. Frequency of application is generally to be provided in instructions-for-use of the composition, taking into account environmental conditions such as crowding and density of people, risk of exposure to virus carriers, time of exposure, and the like.

[0038] Any of the disclosed compositions can be contained in an airtight container or inhaler suitable for intranasal administration of a powder, for personal use. For example, the composition can be contained in a container for personal use that provides said composition at a metered dose and it suitable for multiple administrations, specifically wherein said container is of a volume of from about 10 ml to about 500 ml. The said scenting agent or fragrance can be added to the container together with the dry powder, in addition to any scent comprised in the powder or there instead.

[0039] Still further, the present disclosure provides a method for preventing or reducing infection by a viral pathogen, particularly respiratory viral infection, comprising intranasally administering to a subject in need an effective amount of a composition as disclosed and claimed herein. Administration can be by the subject himself, or by an assisting person or by a member of medical staff. Specifically, the composition is self-administered. Administration can be repeated administration of from one time to six times daily, over a period of from 1 to 30 or more days. The method of treatment or prevention can be effective in preventing or reducing acuteness of cytokine storm in a patient, induced by said viral pathogen. The method for preventing or reducing infection by a viral pathogen, can further comprise using protective facial mask and/or adhering to social distancing.

[0040] In another aspect, the present disclosure provides a method for preventing or treating mild or severe allergic reaction and/or at least one symptom associated therewith, the method comprising intranasally administering to a subject in need an effective amount of a dry powder polymeric composition as disclosed herein. In some embodiments, the allergic reaction is allergic rhinitis (AR). The at least one symptom associated with the allergic reaction can be nasal congestion, watery eyes, and others. [0041] Still further, the present disclosure provides a method for preventing or treating rhinosinusitis and/or at least one symptom associated therewith, the method comprising intranasally administering to a subject in need an effective amount of a dry powder polymeric composition as disclosed herein.

[0042] In all of the disclosed methods of treatment or prevention of viral infection, bacterial infection, or allergic reaction, the said composition of the present disclosure can be is contained in an airtight container or inhaler suitable for intranasal administration of a powder, wherein said container is of a volume of from about 10 ml to about 500 ml, wherein said is suitable for multiple administrations and wherein said container provides said composition at a metered dose, administration can be a single administration or repeated administration of from one time to six times daily, over a period of from 1 to 30 or more days, and can be self-administration by the subject in need or by another person or member of medical staff. The said effective amount of the composition is from about 0.01 mg to 20 mg per single administration.

BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to better understand the subject matter that is disclosed herein and to exemplify how it can be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

Figure 1 shows the particle distribution curves of raw HPMC and microspheres of the present invention prepared in Example la.

Figure 2 shows Scanning Electron Microscope image of the microspheres of the present invention prepared in Example la

Figure 3 shows protection of cells against viral infection by a composition according to present disclosure.

Figure 4 shows protection of cell viability following exposure to H1N1 virus by a composition according to the present disclosure.

Figure 5 shows rate confirmed SARS-CoV-2-infected persons in different populations, as described in Example 4.

Figure 6 shows gel formation in the nasal cavity. 6A: colored Taffix powder immediately after application to intranasal tissue; 6B: Taffix gel formation within nasal cavity; 6C: colored Taffix gel appearance after 5-hour stability test in an oven at 34°C; 6D: colored Taffix gel appearance after 6-hour stability test in an oven at 34°C. Figure 7 shows blocking penetration of allergen by Taffix gel. 7A: Concentration of DerFl (ng/ml) in samples was quantified using the Der fl ELISA 2.0. Average values of duplicates are presented. 10 mΐ of Der fl solution at 80 or 10 pg/ml was added to gels and nets and incubated for 1 or 5 hours. For both concentrations in the five-hour samples Taffix allergy gel results in a significant reduction in Der fl passing the barrier. Technical issues may have resulted in the penetration in the 1-hour sample; 7B: % blocking of DerFl by Taffix gel. 10 mΐ of Der fl solution at 80 or 10 pg/ml was added to gels and nets and incubated for 1 or 5 hours. For each concentration in the five-hour samples Taffix allergy gel blocks more than 85% of Der fl passing the barrier. Intense washing may have resulted in the lower blocking in the one-hour samples.

Figure 8 shows blocking penetration of Ambrosia Artemisiifolia allergen Amb al by Taffix-Allergen gel. 8A: Concentration of Amb al (ng/ml) in samples was quantified using the Amb al ELISA 2.0. Average values of duplicates are presented. 10 pi of Amb al solution at 320 or 80 pg/ml was added to gels and nets and incubated for 1 or 5 hours. For each concentration and incubation time Taffix allergy gel results in a significant reduction in Amb al passing the barrier; 8B: % blocking of Amb al by Taffix gel. 10 mΐ of Amb al solution at 320 or 80 pg/ml was added to gels and nets and incubated for 1 or 5 hours. For each concentration and incubation time Taffix allergy gel blocks more than 80% of Amb al passing the barrier.

DESCRIPTION OF EMBODIMENTS

[0044] Disclosed herein are novel compositions in the form of dry powder, for intranasal administration of a physiologically acceptable muco-adhesive and/or bioadhesive polymer. Generally, a dry powder composition according to the present disclosure comprises at least one type of solid particles (also referred to herein as first type particles). These are essentially spherical solid particles, comprising at least one muco-adhesive and/or bio-adhesive polymer in combination with a pH modifying agent and optionally a biocidal/bactericidal agent, wherein the particles size distribution is such that the size of at least about 90% of said first type particles is about 10-300, 15- 300, 20-300 or 25-300 microns, wherein the size of at least 50% of the particles about 30-100, 35-100 or 40-100 microns and less than about 10%, such as less than 9.5%, 9%, 8.5%, 8%, 7.5%. 7.0, 6.5% or 6% or less of said first type particles are of size of about 5-30 microns, such as less than 30, 25, 20, 15, 10 or 5 microns. [0045] Optionally, the disclosed compositions comprise a second type of solid particles, specifically irregularly shaped solid particles comprising an essentially inert physiologically acceptable component, which serves as carrier or diluent. Where present, the mean size of the second type particles is greater than that of the first size particles.

[0046] Upon intranasal administration to a subj ect of a composition according to the present invention, the polymeric component of the first type particles is solubilized and forms a muco-adhesive film layer and/or gel layer adhered to and/or deposited on the nasal cavity mucosa. The film and/or gel layer prevent at least in part foreign particulates bodies such as viral pathogens, bacteria and allergens from reaching the nasal epithelium and from penetrating the body of the subject. Moreover, upon solubilization of the first type particles, the pH modifying agent modifies the pH of the environment adjacent to said film or gel to below about 3.5, when an acidifying agent is used, or to above about 8, when an alkalinizing agent is used. Viral pathogens are known to be destroyed at pH of under 3.5 or above 8. Thus, any viral pathogens reaching the nasal cavity are not only blocked from reached the subject’s nasal epithelium and penetrating the body, they are also destroyed in situ , once in contact with the acidic or alkaline environment created in the nasal cavity. As shown in the following Examples, also bacteria are destroyed when coming into contact with the polymeric powder composition of the present disclosure. As further shown in the following Examples, penetration of allergens into the body is also at least partially blocked by the polymeric film/gel formed in the nasal cavity upon administration of the polymeric composition of the present disclosure.

[0047] Compositions for intranasal administration in dry powder form are usually produced by milling techniques. As a result, their particle size distribution is broad, and the particles are usually non-spherical and non-uniform. The presence of particles of a mean size of less than 5 microns (pm) should however be avoided. Such very small particles may reach the lung mucosa by nasal spraying or by inhaling, which is unacceptable for intranasal administration from safety point of view. Therefore, the size distribution in embodiments of the presently disclosed compositions is such that about 40-90% said polymer-containing particles are of a mean particle size of about 40-150 microns, at least 50% of the particles are of a mean particle size of about 15-100 microns and less than about 10% of the particles are of a mean particle size of about 5- 30. The presence of less than 10% of particles having a mean diameter of less than 5 microns, renders their use in nasal spraying beneficial for the intranasal administration. [0048] In all embodiments of all aspects of the present disclosure, the physiologically acceptable polymeric component is mucoadhesive polymer and/or is bioadhesive polymer and/or is a gel-forming polymer, which can be a hydrophilic or amphiphilic gel-forming polymer, for example but not limited to any one of hydroxypropylmethyl cellulose (HPMC), hydroxypropyl cellulose (HPC), sodium earboxymethyl cellulose (CMC), a natural gum such a xanthan gum, guar gum, gum acacia and gum tragacanth, starch, such as maize starch, potato starch, chitosan, algal sulfated polysaccharides, a hydrophilic methacrylic polymer, such a hydroxyethyl methacrylic polymer, or hydrophilic acrylic acid polymers such as Carbopol, polyethylene glycol, Poloxamer, polyvinyl alcohol and any co-polymer, grafted polymer or and any mixture of at least two thereof.

[0049] The said functional additive can be, but is not limited to, a pH modifying agent. The said functional agent can be, but is not limited to, an antibacterial/preserving agent or a mixture of at least two thereof as described above.

[0050] The inert carrier, where present, can be any of the carriers listed above. [0051] In all aspects and embodiments of the present disclosure the present composition can be substantially free of excipients other than the at least one functional additive comprised in said first type particles and the inert carrier comprised in said optional second type particles.

[0052] The composition according to the present disclosure can be contained in suitable containers as described above that are user friendly and designed to enable systemic delivery of small and accurately metered doses of intranasal powder compositions by patients themselves or caregivers who are not healthcare professionals or medically trained. Such self-administration is also referred to herein as personal use.

[0053] Thus, in a further aspect the present disclosure relates to a container comprising a composition according to the present disclosure, that can provide predetermined multiple doses of the composition. The container can be designed for personal use by the subject in need, namely self-administration, or by another person. [0054] The disclosed composition can be prepared by a modified spray drying method, as described for example in WO2019/038756, fully incorporated herein by reference, and as described in the following Examples. Thus, to prepare particles of said first type, all constituents, specifically the polymeric component, the pH adjusting agent and the bactericidal/preserving agent where present, are first mixed with a solvent, and the solution is then subjected to spray-drying to give a free-flowing powder.

[0055] As mentioned, the present disclosure provides a method for preventing or reducing infection by a viral pathogen, particularly respiratory viral infection, comprising intranasally administering to a subject in need an effective amount of a composition as disclosed and claimed herein. The method of treatment or prevention viral infections can be effective in preventing and/or reducing acuteness of cytokine storm in a patient, induced by said viral pathogen. The viral pathogen can be any of the viruses listed above and herein. In specific embodiments, the viral pathogen is SARS-CoV-2.

[0056] As can be seen in Example 8 below, a survey conducted during SARS-CoV- 2 pandemic in Israel in a human population highly susceptible to COVID-19, showed that intranasal application of a composition according to the present invention comprising HPMC as the polymeric constituent and citric acid and/or sodium citrate as pH lowering agent (e g. a composition of Example lb below, preferably in addition to standard measures of wearing facial mask and social distancing), has practically prevented infection of users compared to infection of non-users of the composition in the same group of people, and has proven successful. Risk of infection was reduced by 4-fold compared to non-users in the same population (adhering to standard protection measures), and 10-fold lower than general population in same city, presenting a potential significant contribution in the fight against the current pandemic. Application of a composition according to the invention in addition to mask wearing and social distancing, provides significant additional protection to users for several hours. Furthermore, the present results suggest that a composition according to the present invention provided protection to people who used it as instructed, not only in community gathering/s but also at home, when not wearing a mask, even when an infected family member lived in the same household. Similar to SARS-CoV-2, the presently disclosed compositions and methods can provide protection against infection by other viruses, virions or viral fragments that may penetrate airways or body via the intranasal cavity.

[0057] In a further aspect, the presently disclosed polymeric powder compositions for intranasal administration are used in methods for the treatment and prevention of various airways associated allergic reactions and their symptoms, specifically allergic rhinitis (AR), the methods comprising intranasally administering to a subject in need an effective amount of a composition as disclosed and claimed herein. These compositions fit with a new trend of OTC management of AR [Ivancevieh, J.C., et al. CUTT. Treat Options Allergy 6, 410-422 (2019)]. Once administered to the nasal cavity, the compositions form a gel on nasal mucosa, the gel blocking penetration of allergens, as shown in the following examples, specifically Example 10. Allergens are in particular-borne allergens. Non-limiting examples of common airborne allergens are pollen, fungal spores, house dust, house dust mites, animal allergens, insect allergens, industrial allergens, food and drug allergens. Specific examples are Dermatophagoides pteronyssinus (house dust mite) and Ambrosia artemisiifolia. The allergic reaction to be treated/prevented can be mild reaction or severe reaction. Examples of symptoms associated with mild allergic reaction nasal congestion, typical of AR, as well as scratchy throat, watery or itchy eyes, and hives, itching and rash. Specific compositions for treatment/prevention of allergy and its symptoms can comprise as the said scent eucalyptus oil, which is recognized per se for its anti-allergic activity.

[0058] The presently disclosed compositions possess antimicrobial activity, as shown in the following Examples, specifically Example 11. As such, the compositions can be used in method for treating various bacterial infections in nasal cavity and surroundings, the methods comprising intranasally administering to a subject in need an effective amount of a composition as disclosed and claimed herein. Bacteria body size can be of a mean size of from about 0.5 to about 5.0 microns. Pathogenic bacteria can be Gram-positive or Gram -negative bacteria. Non-limiting examples of Gram- positive bacteria are S. pyogenes and S. aureus. Non-limiting examples of Gramnegative bacteria are E. eoli, Salmonella, Shigella, Pseudomonas, Helicobacter, Clostridia and many others.

[0059] In a yet further aspect, the presently disclosed polymeric powder compositions for intranasal administration are used in methods for the treatment of mild or acute rhinosinusitis, the methods comprising intranasally administering to a subject in need an effective amount of a composition as disclosed and claimed herein. As mentioned above, rhinosinusitis may be caused by viral pathogen, by bacterial pathogens, and at times is associated with allergy. Current drug therapies for rhinosinusitis are antibiotics, OTC topical steroids, corticosteroids, combinations of antibiotics and corticsteroids, orally administered steroids, optionally with added antihistamines, mucolytics and decongesestant. Nasal douches such as saline irrigation can be applied. The present polymeric composition are capable of treating and/or preventing rhinosinusitis and worsening thereof, affecting most of the factors underlying this condition - blocking and destroying viral and bacterial pathogens, and preventing or at least reducing penetration of pathogens.

[0060] In all aspects and embodiments of methods of treatment according to the present invention, for all the mentioned specific indications, administration of the polymeric composition can be self-administration by the subject, by an assisting person or by a member of medical staff. Specific indication include but are not limited to viral infection, specifically respiratory viral infection; allergic reaction, whether mild or severe, including but not limited to allergic rhinitis; rhinosinusitis associated with viral or bacterial infection and/or allergic reaction; and bacterial infection. Administration can be repeated administration of from one time to six times daily, over a period of from 1 to 30 or more days, for example 1, 2, 3, 1-5, 1-10, 1-15, 1-20, 1-25 1-30 or more days. In the disclosed method of preventing and/or treating viral infections, the disclosed composition can be designed for from one to six daily administrations. The composition is generally administered intranasally using airtight container or inhaler suitable for intranasal administration of a powder. A suitable container can provide said composition at a metered dose and is suitable for multiple administrations. Specific containers are of a volume of from about 10 ml to about 500 ml, such as about 10, 20, 30, 50, 75, 100, 150, 200, 250, 300, 350, 400, 450 or 500 ml. In all aspects and embodiments of the methods of treatment disclosed herein, the effective dose of the compositions according to the invention that is administered to the subject can be from about 0.01 mg to 20 mg per administration. Dose can be adapted according to the indication, severity of the condition or intensity of pathogen, bacterial or allergen presence and rate of spreading, as well as factors, and is generally determined by attending medical staff.

[0061] In the following description, various aspects of the present application will be described. For purposes of explanation, specific configurations and details are set forth to provide a thorough understanding of the present application. However, it will also be apparent to one skilled in the art that the present application may be practiced without the specific details presented herein. Furthermore, well-known features may be omitted or simplified in order not to obscure the present application. [0062] The terminology used herein is for describing particular embodiments only and is not intended to be limiting of the invention. The term "comprising" and "comprises", used in the claims, should not be interpreted as being restricted to the components and steps listed thereafter; they do not exclude other components or steps. They need to be interpreted as specifying the presence of the stated features, integers, steps and/or components as referred to, but does not preclude the presence and/or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression "a composition comprising A and B" should not be limited to compositions consisting only of components A and B. Also, the scope of the expression "a method comprising the steps X and Z" should not be limited to methods consisting exclusively of those steps.

Definitions

[0063] The terms " bio-adhesive polymer ", " muco-adhesive polymer " and " gelforming polymer " and the like used herein interchangeably, refer to a polymer which following intranasal administration to a subject and dissolution, is capable of forming a polymeric film and/or polymeric gel adheres to and/or is deposited on nasal cavity mucosa for at least 1-6 hours, and can also refer to a mixture of at least two such polymers.

[0064] The terms " composition " and ' 'formulation " may be used herein interchangeably and are to be taken to mean a formulation comprising a physiologically acceptable bio-adhesive or muco-adhesive polymer as defined above, for use in therapeutic and preventive methods of treatment.

[0065] The terms "inert" or " inactive " or " inactive ingredient " or " inert ingredient" , as used interchangeably herein refer to components of the composition, or used in the preparation thereof, that do not instantly react with the active ingredient or adversely affect its properties, or cause any biological effect upon administration to a subject when administered at reasonable amounts to a subject. The general examples of these components are described in "The Handbook of Pharmaceutical Excipients", 4 ^th Edition, by Rowe, Sheskey and Weller, Pharmaceutical press, 2003. Additional exemplary list is Inactive Ingredients Guide of the Food and Drug Administration, USA.

[0066] " Carrier " and " diluent " are used herein interchangeably and refer to an inert ingredient added to the composition. [0067] “ Scent ”, “ scenting agent” and ‘‘ fragrance ” as used interchangeably herein refer to any chemical agent that provides fragrance to the nasal cavity or improves the olfactory properties of the composition upon administration and dissolution in the nasal cavity, and is pharmaceutically/physiologically suitable for nasal administration.

[0068] A " patient " or " subject " that may be administered with the composition according to the presently disclosed subject matter is generally a human in need for prevention and/or treatment of infections or disorders induced by foreign particulate bodies, for example viral pathogens or allergens.

[0069] "pH adjusting agent", "pH modifying agent" "buffering agent" and " buffer " as used herein interchangeably are to be taken to mean any chemical agent that affects the pH of its immediate environment/vicinity.

[0070] The terms "antibacterial/bactericidal agents " and "biocidal/bactericidal agent " are used herein interchangeably. Such agents can also be "preserving agents" . [0071] The term a composition or substance " substantially free of excipients " is to be taken to mean that it does contain more than 5% by weight of such excipient/s. [0072] The terms "treat" , or forms thereof, and the term “ alleviate ”, and the like are to be taken to mean at least partially ameliorate or cure or totally eliminate the patient's condition as defined herein. The term " prevent " as used herein or forms thereof are to be taken to mean preventing or arresting any penetration via the nasal cavity into to the airways or body of a treated subject of harmful foreign particulate bodies such as viruses and allergens.

[0073] The term " suitable " as used herein is to be taken to mean having the properties that enable providing the defined result.

[0074] The terms " physiologically acceptable " and " physiologically compatible " as used herein and variations thereof are to be taken to mean a substance that does not interfere and does not have any adverse effect on the body of a treated subject and its functioning. This term may be interchangeably used with " pharmaceutically acceptable " and " pharmaceutically compatible" .

[0075] The terms “size” and “ mean size ” may be used herein interchangingly, and generally refer to a mean size or mean size range of a recited population or sub population of particles comprised in the disclosed powder composition.

[0076] “About” as used herein generally refers to approximate values. When referred to a dose of drug, or size of particles and the like, “about” should be understood as including the range of a value ± 15 %. When referred to other values, the term should be understood as including the range of a value ± 15%, for example ± 15%, ± 12%, ± 10%, ± 8%, ± 5%, ± 2% or ± 1%. Other similar terms, such as " substantially ", " generally ", "up to" and the like are to be construed as modifying a term or value such that it is not an absolute. Such terms will be defined by the circumstances and the terms that they modify as those terms are understood by those of skilled in the art. This includes, at very least, the degree of expected experimental error, technical error and instrumental error for a given experiment, technique or an instrument used to measure a value.

[0077] As used herein, the term " and/or " includes any combinations of one or more of the associated listed items. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and relevant art and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein. Well-known functions or constructions may not be described in detail for brevity and/or clarity.

[0078] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and relevant art and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein. Well-known functions or constructions may not be described in detail for brevity and/or clarity.

[0079] As used in the specification and claims, the forms "a", "an" and "the" include singular as well as plural references unless the context clearly dictates.

[0080] Throughout this specification and the Examples and claims which follow, unless the context requires otherwise, the word “comprise”, and variations such as “comprises” and “comprising”, will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

[0081] The presently disclosed subject matter is further illustrated by the following examples, which are illustrative only and are not to be construed as limiting the scope of the invention. Variations and equivalents of these examples will be apparent to those skilled in the art in light of the present disclosure, the drawings and the claims herein. [0082] It is appreciated that certain features of the presently disclosed subject matter which are, for clarity, described in the context of separate embodiments, can also be provided in combination in a single embodiment. Conversely, various features of the presently disclosed subject matter, which are, for brevity, described in the context of a single embodiment, can also be provided separately or in any suitable sub-combination. [0083] Although the presently disclosed subject matter has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.

[0084] All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent and patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as relevant prior art to the presently disclosed subject matter.

DESCRIPTION OF NON-LIMITING EXAMPLES

Materials

Polymer/s

[0085] Hydroxypropylmethyl cellulose (HPMC), hydroxypropyl cellulose (HPC), sodium carboxymethyl cellulose (CMC) from Dow chemicals, a natural gum such a xanthan gum, guar gum, gum acacia and gum tragacanth, starch, such as maize starch, potato starch, chitosan from Merck- Sigma- Aldrich a hydrophilic methacryJic polymer, such a hydroxyethyl methacrylic polymer, or hydrophilic acrylic acid polymers such as Carbopol from Lubrizol, polyethylene glycol, Poloxamer, polyvinyl alcohol from BASF. pH modifying agents [0086] L-pyroglutamic acid (PCA); ascorbic acid, citric acid, phytic acid, succinic acid, acetic acid, citric acid, hydrochloric acid, lactic acid, tartaric acid, malic acid, salts thereof hydrates and anhydrates or monohydrate from Merck-Sigma- Aldrich.

Antibacterial preservative /surfactant agents

[0087] Benzoic acid, chlorocresol, diazolidinyl urea, imidurea, edetic acid and its salts, potassium sorbate, sorbic acid and its salts, benzethonium chloride and Benzalkonium chloride from Merck-Sigma-Aldrich.

Scenting/fragrance agent

[0088] Menthol, eucalypt oil and vanillin were purchased from Merck-Sigma- Aldrich.

Example 1: Preparation of a composition of HPMC with acid To 100 ml of 10% HPMC solution (Benecel E3) 1.85 gram of 0.1M citric acid solution were added providing pH 3.62. This viscous solution was spray dried at inlet temperature 120°C (outlet 80-82 °C); pump 10; aspirator 100%; air flow 30 on scale. The free-flowing powder was obtained.

Example la: Preparation of a composition of HPMC with acid and benzalkonium chloride

To 100 ml of 9% HPMC solution were added 0.7 g citric acid, 0.3 g sodium citrate and 0.01 g of benzalkonium chloride, providing pH 3.7. The resulting viscous solution was spray-dried at inlet temperature 120°C (outlet 80-82 °C); pump 10; aspirator 100%; air flow 30 on scale. A free-flowing powder was obtained.

Example lb: Preparation of a composition of HPMC with acid, benzalkonium chloride and menthol

To 100 ml of 9% HPMC solution were added 0.7 g citric acid, 0.3 g sodium citrate, 0.01 g of benzalkonium chloride and 0.2 g of menthol, providing pH 3.7. The resulting viscous solution was spray-dried at inlet temperature 120°C (outlet 80-82 °C); pump 10; aspirator 100%; air flow 30 on scale. A free-flowing powder was obtained. This composition is also referred to herein as Taffix, or Taffix™, or Taffix powder. Example lc: Preparation of a composition of HPMC with acid, benzalkonium chloride and eucalypt oil To 100 ml of 9% HPMC solution were added 0.7 g citric acid, 0.3 g sodium citrate, 0.01 g of benzalkonium chloride and 0.2 g of eucalypt oil, providing pH 3.7. The resulting viscous solution was spray-dried at inlet temperature 120°C (outlet 80-82 °C); pump 10; aspirator 100%; air flow 30 on scale. A free-flowing powder was obtained. This composition is also referred to herein as T affix- Allergy, or T affix- Allergen.

Example 2: Preparation of composition of HPMC with base

To 100 ml of 10% HPMC solution (Benecel E3) 0.21 gram of 0.1M Sodium hydroxide solution was added providing pH 8.97. This viscous solution was spray dried at inlet temperature 120°C (outlet 80-82°C); pump 10; aspirator 100%; air flow 30 on scale. The free-flowing powder was obtained.

Example 2a: Preparation of a composition of HPMC with base and benzalkonium chloride

To 100 ml of 10% HPMC solution (Benecel E3) were added 0.21 g 0.1M Sodium hydroxide solution and 0.01 g benzalkonium chloride, providing pH 8.97. The viscous solution obtained was spray-dried at inlet temperature 120°C (outlet 80-82°C); pump 10; aspirator 100%; air flow 30 on scale. A free-flowing powder was obtained. Example 2b: Preparation of a composition of HPMC with base, benzalkonium chloride and menthol

To 100 ml of 10% HPMC solution (Benecel E3) were added 0.21 g 0.1M Sodium hydroxide solution, 0.01 g benzalkonium chloride and 0.2 g of menthol providing pH 8.97. The viscous solution obtained was spray-dried at inlet temperature 120°C (outlet 80-82°C); pump 10; aspirator 100%; air flow 30 on scale. A free-flowing powder was obtained.

Example 3: Preparation of a composition of HPMC with salt To 200 ml of 3% HPMC and 1% NaCl solution (Benecel E3) pH 5.5. This viscous solution was spray dried at inlet temperature 120°C (outlet 80-82 °C); pump 15; aspirator 100%; air flow 30 on scale. The free-flowing powder was obtained.

Example 4: Particle size distribution

The obtained composition of Example 3 and starting HPMC material were subjected to particle size analysis using a Malvern Laser Diffraction instrument. As shown in Figure 1, the following particle size distributions were obtained: i. Benecel 3E (Ashland)- HPMC unprocessed: Dio- 11.2 microns; Dso- 58.3 microns; D90- 144 microns and D100- 3470 microns; ii. Example la (Nasus) Dio- 22.8 microns; D50- 62.6 microns; D90- 163 microns and D100- 345 microns

The particle size distribution of spray dried microspheres of the present inventions are much uniform, have better spray ability and solubility. In addition, they meets safety requirements for Nasal powders. [Nasal Spray and Inhalation Solution, Suspension, and Spray Drug Products — Chemistry, Manufacturing, and Controls Documentation; Guidance for Industry; CDER, July 2002],

Example 5: protection of cells against GFP Lentivirus infection

MDCK cells were incubated with polymeric compositions prepared according to the present inventions with pH = 3.5 (according to Example lb, TAFFIX in Figure 4)) and pH = 7.9 (according to Example 2), and the protective effect of gel ( mechanical) and low pH (chemical ) against viral infection was tested using a fluorescent GFP lentivirus.

As shown, cells that were not protected by a composition according to the invention were significantly infected with the virus, while cells protected with a gel according to the invention were considerably less infected, showing the protective effect of the gel against viral penetration.

Example 6: Protection of cell’s viability upon exposure to N1H1 Influenza virus . MDCK cells pre-treated with a composition as prepared in Example lb were exposed to N1H1 Influenza virus for 5 and 30 minutes, and the protective effect of the composition was tested in comparison to cells pretreated with saline solution. Cell viability was measured using a cell proliferation assay kit (XTT based).

The results are shown in Figure 3.

As shown in Figure 3, pretreatment of the viruses with saline for 5 minutes showed reduced cells viability to 27% and pretreatment of viruses with HMPC alone (pH-6.8) reduced cell viability to 37%.

Remarkably, pretreatment with the composition of Example lb (TAFFIX in the Figure) protected 88% of cells after 5 minutes pretreatment, and 90% after 30 minutes pretreatment, attesting to a fundamental role of acidity in disabling aggressive respiratory viruses.

Example 7: Protection of cell viability upon exposure SARS-CoV-2.

The composition according to Example lb was tested was to test establish that it can form a protective barrier against SARS-CoV-2. A gel of the composition was preformed on a 40 pm nylon filter, and then seeded with 10,000 PFUs of virus. An untreated filter, seeded with the same amount of virus, was used as an untreated control. After a 10-minute incubation the bottoms of the filters were washed with culture medium and then tested for live viruses by plaque assay and for viral RNA using qRT- PCR. The composition of Example lb reduced the number of live viruses by more than 99%, and in most experiments no virus was detected at all or the amount of virus present was below the limit of detection of the assay in the undiluted flow through. Using qRT-PCR techniques, treatment with the composition of Example 1 reduced the amount of viral RNA by more than 4 logs.

Example 8: Protection against SARS-CoV-2 infection — survey in humans A polymeric composition according to the invention comprising HPMC as the polymeric component and citric acid and sodium citrate as pH lowering agent, as prepared in Example lb (also referred to herein by Taffix or Taffix™ or Taffix powder) was used in the survey described below.

Materials and methods

Spray containers for intranasal administration of the powder Taffix composition were used, each for personal use by each participant of the survey. The container provides the composition at a metered dose and it suitable for multiple administrations. In the current survey, the volume of the container was 20 ml. and amount of the single administered Taffix powder was 3-5 mg in each nostril. The powder is administered into the nose of the user by insufflation every 5 hours by gentle press of the plastic container (bottle with dropper) and directing the dropper toward one, then other nostril.

Population.

During the high holiday season in Israel a prospective user survey in an ultraorthodox community the city of Bnei Brak (BB), Israel. "Real-life" effect of Taffix in preventing infection following large social gathering in a closed environment was surveyed in BB around the Rosh Hashana (Jewish New Year) holiday, such gathering being a potential "super-spread" event.

Collaboration was with a medium sized synagogue community of some 250 members. Following preliminary presentation of information and notification, members of the community expressed their interest in using Taffix throughout Rosh Hashana prayers and over the following two weeks. Each member could collect a Taffix container (for intranasal administration at metered doses, which is suitable for multiple administrations, as described herein) at the synagogue and received instructions for proper usage of the device. Members also committed to use Taffix whenever encountering a large social interaction and re-apply Taffix every 5 hours when still in a crowded area, for the two weeks following the Holiday. Cooperation of the community members strongly supported and encouraged by the spiritual leadership of the community. Weekly reminders to all participants were sent directly through the community email system and close attention and monitoring was carried out to substantiate the number of new cases in the community. It was explained to participants that use of Taffix offers an extra layer of protection in addition to, not in replacement of mandatory use of masks and adherence to social distancing.

Taffix containers were collected by participants one day before the Holiday. All in all, 113 containers of Taffix were collected by community members.

By day 14 after the Rosh Hashana holiday, members of the community were all contacted and were asked to report whether they have used Taffix, how often and under what circumstances they used it, and whether there were new cases of COVID-19 (SARS-CoV-2 infection) since the Holiday. Information about the total confirmed new COVID-19 cases in the remainder of the community was also collected and confirmed.

Results

243 members of the Synagogue participated in the two days holidays prayers (at least 7 hours spent in the synagogue each day in a closed room).

113 containers were collected by the synagogue members one day before the holiday. Eighty-three (83) members, men, women and children above the age of 12 years, actually used Taffix, out of which 81 used it regularly as instructed (Per-Protocol, PP participants) before entering a populated area and every 5 hours, two (Intent-to Treat, ITT participants) used it improperly “once or twice” throughout the 14 days period. There were no reports of side effects and most users commented on ease of use and had no problem in adapting the use of Taffix to their daily routine.

One hundred and sixty (160) members of the either did not collect the Taffix at all or collected it and did not use it at all, not even once.

All 81 members who used Taffix regularly according to the instruction for use were not infected at all during the study period of 14 days following Rosh Hashana.

18 members of the community were confirmed as new COVID 19 infected patients in the 14 days following the Holiday, of which 16 did not collect or use Taffix, two collected Taffix and used it incorrectly, that being only once or twice throughout the whole two weeks period ITT). One of them was diagnosed only 2 days after Rosh Hashana.

In two families, one family member who did not use Taffix was confirmed positive while the other family members sharing the same household who did use Taffix (PP) were not infected during the 14 days of follow-up. The Rabbi, who used Taffix regularly was not infected, while a man who was sitting directly next to him during the 7 hours of prayer services and did not use Taffix was one of those infected. To be clear, the Rabbi (Taffix user) did not get infected by the infected (non-Taffix user) congregant, who sat next to him for hours.

Of note in this time period the number of new cases in the city of Bnei Brak increased by 1.6 folds as positivity rates went from 17.6% to 28.4%. In this connection it is noted that the tested population generally adhere to wearing masks and social distancing, hence the difference between the members not using Taffix and the general population of Bnei Brak.

Statistical analysis:

Statistical methods

Results analysis was performed first on the ITT (Intent-to-Treat) population data (members who occasionally used Taffix) and then on the PP (Per-Protocol) population (members who used Taffix regularly according to instructions).

The Fisher's exact test for the comparison of two proportions (from independent samples), expressed as a percentage, was applied to compare the contagion rate between Taffix users and non-users.

Fisher's exact test is used to calculate an exact P-value for a 2x2 frequency table with small number of expected frequencies. All tests are two-tailed, and a p-value of 5% or less is considered statistically significant.

The data was analyzed using the SAS ® version 9.4 (SAS Institute, Cary North Carolina).

Statistical results

In the ITT population, 2.4% of the Taffix users (2/83) and 10% of the Taffix nonusers (16/160) were infected, thus a difference of 7.6%.

In the PP population, 0% of the Taffix users (0/81) and 10% of the Taffix nonusers (16/160) were infected, thus a difference of 10%.

For both the populations, the contagion rate for the Taffix users was significantly lower than for Taffix non-users.

The difference in levels of infected members between the tested non-users population (10%), total Bnei Brak population(28.1%) and total Israeli population (12.1%) during the test period can be attributed to adherence of non-users tested population to general measures of mask wearing and social distancing.

Intranasal administration of a composition in accordance with the present invention resulted in prevention of COVID-19 not only compared to occurrence in local population of Bnei Brak (almost 29%) or national (12.1%), but remarkably also compared to a population adhering to standard preventive measure as the population of the survey - no infection vs. 10% infection.

Example 9 — Physical stability of a polymeric gel (Taffix gel) formed on nasal tissue A polymeric powder composition of Example lb (Taffix) to which an inert, blue- colored agent was added for gel contrast was prepared. The composition was loaded into a Multidose Powder Device for intranasal administration, as described herein. Upon administration and contact with nasal cavity tissue the powder spontaneously converts to a gel. The blue powder was sprayed within pig nasal cavity. The gel formation time, initial and final pH levels and gel appearance within 6 hours are reported below.

Materials and equipment

Powder composition of Example lb mixed with Instacoat Color Blue loaded into Multidose Powder Device.

Sliced pig nose - supplied by Lahav, stored at 5°C±3°C. pH sticks: range 3-6

Saline solution: 0.9% NaCl in water(w/w)

Glass dishes and covers Oven binder 34°C Results

Gel Formation Rate

About 92 mg of Taffix powder were released from the multidose device after 8 presses, 4 presses in each pig nostril (Figure 6A).

Gel gloss formation was observed immediately after Taffix application, and gel formation was completed within 1 min 12 seconds (Figure 6B).

This shows that that protective gel is formed within the nasal cavity immediately following Taffix powder nasal application.

Gel Stability on Nasal Surface

The treated pig nose slices were placed in an oven at 34°C. Visual examination was made every hour (at 1, 2, 3, 4, 5 and 6 hrs.). The gel gloss appearance was observed after 5 hours in the oven (Figure 6C). After 6 hours in the oven glossy shine faded. The blue-colored thin film-like substance was clearly observed also after 6 hrs. (Figure 6D)

Acidity of Gel on Nasal Surface

The initial pH of the gel was 3.6. The pH of the gel after 6 hours in the oven (last measurement) was 4.4.

This shows that Taffix provides protective acidic environment for at least 6 hours after nasal application.

Example 10 — Protection against allergens A composition of Example lb (referred to above and below by Taffix) is used in the tests described below. This specific composition comprised eucalyptus oil as fragrance instead of menthol, and at times is referred to herein as Taffix-Allergen.

Objectives:

The objective of the study is to evaluate the blocking effect of Taffix on different allergens.

Rationale and assay principles

According to an assay developed by the applicant, the barrier effect of Taffix for allergens is investigated. A hydrogel is formed on one face of a cell strainer made of a nylon net with 40 pm holes. Two different allergens are applied independently onto the gel each at two concentrations, and are collected from the other face of the strainer at two different time points following application to the gel. The collected allergens are quantified using commercially available means, such as ELISA kits.

Experimental setup

1.1. A hydrogel is formed on one face of a cell strainer (Biologix 15-1040) made from a nylon net with 40 pm holes. The following two allergens:

(i) Natural Amb a 1 ( Ambrosia artemisiifolia )

(ii) nDer p 1 ( Dermatophagoides pteronyssinus (house dust mite) are independently applied onto the hydrogel each at two concentrations. Each concentration is incubated on the hydrogel for two periods of time.

1.2. As a positive control, the allergens are applied onto the strainer without the hydrogel.

1.3. Assay is performed in triplicates (biological triplicates).

1.4. Following incubation as above, the allergens are collected from the other face of the strainers, and are measured using commercial ELISA kits. The ELISA assay is performed in triplicates (technical triplicates).

1.5. The test is conducted with 2 test materials:

1. T affix-allergy powder

2. Reference powder

A. 10 pi Der fl solution was added at 80 pg/ml and 10 pg/ml to Taffix Allergen gels and was incubated for 1 hour and 5 hours. All samples were performed in duplicates. After incubation, samples were washed 3 times on the lower side of net with 0.5 ml molecular grade water in order to collect the allergen that had passed through the gel. At the third wash of the one hour samples bubbles were seen. This may indicate that the gel was dissolved. Thereafter all samples were diluted into assay buffer and added to Der fl ELISA 2.0. Samples were diluted so that the expected concentration would be within the assay range. The actual concentrations in the undiluted samples were back-calculated and is presented in Figure 7A. It can be appreciated that for both concentrations at five hours incubation time the concentration is significantly lower in the Taffix Allergy gel sample than the control without gel. In the one hour incubation of the 10 pg/ml samples a significant but lower reduction is detected. The one hour, 80 pg/ml samples had technical differences.

Figure 7B shows the degree of blocking (%) of Der fl by the Taffix Allergy gel for the two allergen concentrations at 1 hour and 5 hours incubation.

The results are summarized in Table 1 below:

Table 1: Summary of % blocking of Der fl penetration by Taffix Allergy gel

B. Taffix-allergen gel was tested for its ability to block natural Amb a 1 (, Ambrosia artemisiifolia ) allergen.

10 mΐ Amb al solution was added at 320 pg/ml and 80 pg/ml to Taffix-Allergen gels and was incubated for 1 hour and 5 hours. All samples were performed in duplicates. After incubation, samples were washed 3 times on the lower side of net with 0.5 ml molecular grade water in order to collect the allergen that had passed through the gel. Thereafter the samples were diluted into assay buffer and added to Amb al ELISA 2.0. Samples were diluted so that the expected concentration would be within the assay range. The actual concentrations in the undiluted samples were back-calculated and is presented in Figure 8A. It can be appreciated that for every concentration and incubation time the concentration is significantly lower in the Taffix- Allergy gel sample than the control without gel. Figure 8B shows the degree of blocking (%) of Amb al by the T affix- Allergy gel for the two allergen concentrations at 1 hour and 5 hours incubation.

The results are summarized in Table 2 below:

Table 2: Summary of % blocking of Amb al penetration by Taffix Allergy gel

Example 11 — Antimicrobial activity of Taffix powder Test Article: Taffix (powder) prepared as in Example lb.

Control article: Nasaleze™ (powder)

Test Microorganisms:

Staphylococcus aureus (ATCC 6538) - Gram positive cocci Pseudomonas aeruginosa (ATCC 9027) - Gram negative rods Test media, buffer and materials:

Tryptic Soy Agar (TSA), Neogen

Tryptic Soy Agar with 3% Tween 80 and 0.3% Lecithin

Buffer solution 1 : sodium chloride buffer solution pH 7.0

Buffer solution 2: Sodium chloride buffer solution pH 7.0 with 3% Tween 80 and 0.3% Lecithin.

Test Procedure:

1. lg product (Taffix) was mixed with 5ml test microorganism suspension containing about 10 ⁶ CFU/ml and 45ml buffer solution 1. Control sample (without product) was prepared the same manner (Inoculum size). The number of microorganisms in 1ml suspension was examined at time "0" and after 3 hours storage at ambient temperature. The test was performed by pour plate method in appropriate dilutions (from 10 ^'2 up to 10 ^'4 ) on TSA medium in duplicates.

Results: Number of test microorganisms, average of two tubes, CFU/ml

2. To ensure the validity of results, the neutralizing agents: 3% Tween 80 and

0.3% Lecithin were added to the Buffer pH 7.0 and TSA before sterilization. Test was repeated as above.

3. To exclude low pH of initial solution as inhibiting microbial growth, the test was repeated with a solution with pH adjusted to neutral level.

4. lg Nasaleze™ powder (used as control article) was suspended in 50ml buffer solution 1 and inoculated with 0.1 ml suspension of test microorganisms containing about 10 ⁷ CFU/ml. Control sample without product was prepared the same manner (Inoculum size). The number of microorganisms in 1 ml suspension was examined at time "0" by pour plate method in appropriate dilutions on TSA medium in duplicates.