Patent Application
20130028848
This disclosure relates to barrier-forming compositions and methods for preventing communicable diseases.
There has been a longstanding need for devices, compositions, and other treatments that will effectively prevent communicable diseases. Attempts at solving this problem include wearing masks or respirators and avoiding or quarantining of individuals or animals that are known or expected to be sick or carrying germs. Such approaches are common in certain countries where masks are worn by persons encountering contaminated environments such as public transportation or public gathering places.
Other attempts to prevent infection have included large amounts of zinc, vitamins, or herbs that are theorized to work internally to boost the body's immune system.
While numerous solutions exist for killing microorganisms once they have contacted a person or animal, the effectiveness of such solutions is dependent on quick recognition of the germ contact and application of the germ-killing composition prior to the microorganism binding to a mucosa, whereby it would enter the body and infect the individual. For example, washing with an anti-bacterial soap may be effective for killing germs on the hands; however, it is very easy for a person to unwittingly touch a contaminated surface and put their hands near or in their mouth or nose before washing their hands.
Physical devices such as masks are uncomfortable, zinc, vitamin C, and herbal remedies have unproven results, and solutions for killing germs that have already contacted the body are often ineffective for prevention of infection since they are intermittent, transitory options that do not provide sustained protection.
Compositions have been developed for forming blocking barriers topically on human skin or in the oral or internal cavities. However, such compositions are not for preventing infection of communicable diseases.
In an embodiment, a method for blocking, neutralizing, or killing microorganisms that cause infectious disease in a mammal prior to or during the mammal encountering a contaminated environment or item includes: identifying a contaminated environment or item, wherein the contaminated environment or item is known or expected to be contaminated with harmful viral, fungal, or bacterial microorganisms; and administering a therapeutically effective amount of a barrier-forming composition to a mucosa of the mammal prior to or during the mammal encountering the contaminated environment or item. The barrier-forming composition provides a barrier on the mucosa that inhibits the microorganisms from contacting the mucosa.
In an embodiment, a method for blocking, neutralizing, or killing microorganisms that cause infectious disease, includes: identifying a contaminated item or environment, wherein the contaminated, item or environment is known, or expected to be, contaminated with harmful viral, fungal, or bacterial microorganisms; and forming a barrier on an apparatus prior to or during the apparatus encountering the contaminated environment and prior to or during the apparatus encountering a mucosa of a mammal. The barrier-forming composition provides a barrier on the apparatus that traps and kills the microorganisms, thereby preventing the microorganisms from contacting the mucosa or causing infection.
In an embodiment, a method for blocking, killing, or neutralizing microorganisms that cause infectious disease in an immunocompromised mammal, includes: identifying a disrupted area in a mucosa of the mammal; and administering a therapeutically effective amount of a barrier-forming composition to at least the disrupted area of the mucosa of the mammal. The barrier-forming composition provides a barrier on the disrupted area of the mucosa that effectively inhibits microorganisms from contacting a disrupted area of the mucosa.
In an embodiment, a method for blocking, neutralizing, or killing microorganisms introduced into a mammal's oral, nasal, or pharyngeal cavity through the mammals hand-to-mouth or hand-to-nose contact includes: identifying a contact with a contaminated item by a hand of the mammal, wherein the contaminated item or environment is known, or expected to be, contaminated with harmful viral, fungal, or bacterial microorganisms; and administering a therapeutically effective amount of a barrier-forming composition to an oral, nasal, or pharyngeal mucosa of a mammal prior to the mammal's hand-to-mouth or hand-to-nose contact. The barrier-forming composition provides a barrier on the mucosa that inhibits the microorganisms from contacting the mucosa, and neutralizes or kills the microorganisms.
In an embodiment, a method for blocking, neutralizing, or killing allergens or airborne irritants of an oral or pharyngeal mucosa in a mammal prior to or during the mammal encountering a contaminated environment, includes the following: identifying a contaminated environment, based on the contaminated environment or item being known or expected to be contaminated with allergens or airborne irritants to the mucosa; administering a therapeutically effective amount of a barrier-forming composition to an oral or pharyngeal mucosa of the mammal prior to or during the mammal encountering the contaminated environment. The barrier-forming composition provides a barrier on the mucosa that inhibits the microorganisms from contacting the mucosa.
The articles “a” and “the,” as used herein, mean “one or more” unless the context clearly indicates to the contrary.
The terms “item” and “apparatus” are used synonymously herein.
The term “therapeutic,” as used herein, is meant to also apply to preventative treatment.
The term “or,” as used herein, is not an exclusive or, unless the context clearly indicates to the contrary.
The mucosa lining the mouth, gut, and body cavities of mammals represents the first barrier to the entry of pathogenic microorganisms to mammalian bodies where they can cause both local and systemic infections. The epithelium mucosal lining forms a barrier that reduces the entry of commensals organisms (Monica Boirivanta and Warren Strober, “The Mechanism of Action of Probiotics” Current Opinion in Gastroenterology 2007, 23:679-692).
In this application, a method and composition is disclosed that blocks or neutralizes microorganisms that cause infectious disease from contacting or infecting mucosa, which in turn prevents microorganisms from disseminating into body and causing infection. The method and composition incorporates an antimicrobial agent that can inhibit microorganisms (bacteria, fungi, and viruses) known to cause infections. The method protects human mucosa by forming a barrier over it and an antimicrobial agent is included that can kill or inhibit microorganisms (bacteria, fungi and viruses). This dual action composition and method (barrier plus antimicrobial) is applicable to human or other mammal mucosa or, for example, surfaces in the oral cavity, nasal cavity, vaginal cavity, throat, and other orifices, including, but not limited to, the ears. It can also be applied to medical devices, such as trachea devices. This unique and unexpected solution addresses a long-felt but unresolved need for preventing communicable diseases caused by microorganisms.
A barrier-forming composition that is safe (i.e. does not cause damage to the mucosa) and forms a barrier that inhibits the passage of pathogenic microbes through the mucosal tissues is desirable. Another desirable property is an ability to inhibit microbial growth through static or cidal activity for an extended period of time. Without being bound by theory, the mechanism of action of the barrier-forming composition disclosed herein is based on a synergistic dual-action mechanism, in which germs are trapped in the formed barrier, and subsequently killed by the antimicrobial active ingredient. In an embodiment the barrier-forming composition is not hydrophilic, which, without being bound by theory, is theorized to enhance it sustained effectiveness.
As shown in the Examples below, the properties of the barrier-forming composition and its effectiveness to prevent a wide variety of communicable diseases were assessed using at least ten different approaches based on: (1) an in vitro anti-microbial susceptibility testing; (2) an in vitro time kill assay; (3) an in vitro biofilm model; (4) an in vitro filter insert-based model, (5) an in vivo-like engineered human oral mucosa (EHOM) model; (6) electron microscopy evaluation; (7) hydrophobicity assay; (8) physico-chemical compatibility assays; (9) cell culture-based model using monolayer of human cell lines; and (10) human clinical trials.
The method and composition described herein may be particularly useful when a human, or more generally, a mammal, has a disrupted mucosa. A disruption may be caused be a wound or scratch. The mucosa of the oral cavity and gastrointestinal (GI) tract serve as an important mechanical barrier that helps to prevent a local or systemic invasion of various microbes and the absorption of microbial products that are normally present in the oral cavity and the lumen of the gut. “Gastrointestinal mucosal injury in experimental models of shock, trauma, and sepsis,” Crit. Care Med. 1991; 19:627-41.). Derangement in the barrier function of the mucosa plays a central role in the pathophysiology of systemic infection. In other words, disruption of this mucosa will lead to infections.
Elimination or reduction of the risk of a breach in the first line of defense is important, and the maintenance of mucosal integrity is important. (Anders Heimdahl, “Prevention and Management of Oral Infections in Cancer Patients” Supportive Care in Cancer, Vol. 7, No. 4, 224-228 (1999).) Thus, having an intact mucosa is an important host defense against systemic infection, particularly in immunocompromised patients (e.g. cancer patients). (Shahab A. Khan, John R. Wingard, “Infection and Mucosal Injury,” Cancer Treatment Journal of the National Cancer Institute, Monographs No. 29 (2001). A barrier-forming composition that blocks and kills harmful microorganisms and that does not interfere with healing of a disrupted mucosa is a unique and unexpected solution to the susceptibility of the problems of those with disrupted mucosa, particularly those that also have immunodeficiency.
In an embodiment, a barrier-forming composition may be administered in a method for preventing or inhibiting an infectious disease in a mammal. By prevention, it is not meant that no infection from microorganisms is possible, but that the risk of infection from microorganisms encountered subsequent to application of the barrier-forming composition is reduced. For the full preventive effect, the barrier-forming composition should be applied prior to the mammal encountering a contaminated environment or item. This is not to say that some benefit could not be obtained from administering the barrier-forming composition during the encounter with a contaminated environment or item. The use of the term “mammal” herein, means a human or animal commonly defined as a mammal.
In another embodiment, a barrier-forming composition is administered in a method preventing an infectious disease in mammal with a disrupted mucosa, such as for example an immunocompromised mammal. The disrupted area in a mucosa of the mammal is identified and a therapeutically effective amount of a barrier-forming composition is administered to at least the disrupted area of the mucosa of the mammal. The barrier-forming composition provides a barrier on the disrupted area of the mucosa that effectively inhibits microorganisms from disseminating to a disrupted area of the mucosa.
In another embodiment, the barrier-forming composition is administered on an item or apparatus prior to the apparatus encountering a contaminated environment and prior to the apparatus encountering a mucosa of a mammal. The barrier-forming composition provides a barrier on the apparatus that traps and kills the microorganisms, thereby preventing the microorganisms from passing to the mucosa or causing infection.
In an embodiment of the method of preventing an infectious disease, a step includes identifying a contaminated environment that the mammal or item is expected to encounter. The contaminated environment is an environment such as an indoor or outdoor space or a proximity to another mammal or human that is known or expected to be contaminated with harmful viral, fungal, or bacterial microorganisms. The determination of whether a given environment may be contaminated may be based on the time of year, published information on flourishing diseases in the community, or observing others that appear to be sick or spreading germs by sneezing, etc.
Predicting or identifying whether the contaminated environment or item will be encountered can be a decision based on whether the mammal plans or expects to enter the environment or encounter the item in the near future. This may include estimating a time when the contaminated environment or item will be encountered. The barrier-forming composition may then be administered about twenty-four hours or less prior to the estimated time of encounter with the contaminated environment or item, such as, for example, about sixteen hours or less, about twelve hours or less, about six hours or less, or about two hour or less. The barrier-forming composition sets up quickly and should be operable to prevent or inhibit harmful microorganisms from infecting mucosa, for example, within less than one minute of application, such as within 30 seconds. Thus, it could be applied during the encounter with the contaminated environment or item and have effectiveness.
Harmful microorganisms are those known to cause infectious disease such as, for example, the treatment and prevention of infectious diseases, such as communicable diseases caused by microorganisms, such as Candida species (e.g. C. albicans, C. glabrata, C. krusei, C. tropicalis), Staphylococcus species (including methicillin-resistant S. aureus, MRSA), Streptococcus species (e.g. S. sanguis, S. oxalis, S. mitis, S. salivarius, S. gordonii, S. pneumoniae), Acinetobacter baumannii, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, and other microorganisms such as microorganisms that cause upper respiratory infections, and cold and influenza viruses. In an embodiment, the barrier-forming composition and method of treatment and prevention described herein may be useful, for example, for prevention of sexually transmitted diseases [such as, for example, infections caused by human immunodeficiency virus (HIV), Herpes simplex, or human papilloma virus (HPV)], common cold (e.g. caused by rhinovirus), and infections caused by Epstein-Barr Virus (EBV).
The barrier-forming composition has shown effectiveness against microorganisms with a diameter of, for example, about 30 nm or greater, such as about 100 nm (HIV, spherical), about 100 to about 300 nm (influenza, spherical and elongated forms), about 120 nm to about 260 nm (EBV spherical/disk forms), and about 30 nm (rhinovirus, spherical). Thus, the composition should also be effective against other microorganisms with diameters of about 30 nm, or greater than about 30 nm.
The microorganisms may be air-borne microorganisms. In an embodiment the microorganisms are those that cause communicable diseases. In an embodiment, the microorganisms do not include those that cause allergic reactions or dental problems, such as, for example, cavities (caries), gingivitis, or seasonal allergies. Similarly, in an embodiment, the method of prevention does not solely or additionally prevent dental problems or allergic reactions, such as, for example, cavities (caries), gingivitis, or seasonal allergies. In another embodiment, however, microorganisms, such as fungi that may generally be classified as allergens, other allergens, and airborne irritants to the mucosa, are blocked by the barrier and the method. In the allergen blocking embodiment, the identification of the contaminated environment may, for example, be based on the season of the year, or pollen or other allergen or irritant forecasts. It may also be based, for example, on the mammal's expectation to be in a location known or expected to produce a high number of allergens or airborne irritants, such as, for example, an outdoor environment, including, for example, a forest, a park, or a lake.
In an embodiment, the barrier-forming composition and method of treatment and prevention described herein may be useful, for example, for prevention of infections in environments such as hospitals and infections common in such environments that are contaminated with infectious microorganisms. As mentioned above, the methods and compositions disclosed herein may be especially applicable for immunocompromised patients. In addition, the barrier-forming composition may be useful for prevention of infections by microorganisms that commonly infect wounds.
The contaminated environment may include, for example, a public transportation vehicle, a public gathering place, and a room or vehicle containing a mammal known or expected to be ill, or a close proximity to a mammal known or expected to be ill. More information on environments commonly recognized as contaminated environments, such as an airplane, a nursery, and a health center, is disclosed in Yang, et al., “Concentrations and Size Distributions of Airborne Influenza A Viruses Measured Indoors at a Health Centre, a Day-Care Centre, and on Aeroplanes,” J.R. Soc. Interface (Feb. 7, 2011), which is incorporated herein by reference.
More specifically, in an embodiment, the public transportation vehicle may be, for example, an airplane, a bus, or a taxi. A public gathering place may be, for example, a doctor's office, a hospital, a school, a nursery, a church, a hotel, or a restaurant. The close proximity to a mammal known or expected to be ill may be, for example, within a one foot radius, or in the same motor vehicle with the mammal. A publicly used airplane may be mentioned as a common and particularly noteworthy example of an environment that many would identify as being a contaminated environment.
In an embodiment, the barrier-forming composition and method of treatment and prevention described herein may be useful, for example, for prevention of infections from items that may be contaminated in activity related treatments, such as, for example, ventilator use (which would include medical devices related to the ventilator and contacting the patient). As another example of a contaminated item, treatment and prevention of fungal infections through applications to the body, and or items or surfaces coming into contact with the body, such as shoes, may also be mentioned. In an embodiment the contaminated item may be, for example, a food, a drink, utensils, drink containers and accessories, an item for use by children, a medical apparatus, or a dental apparatus.
In an embodiment of the method of preventing an infectious disease, a step includes administering a therapeutically effective amount of a barrier-forming composition to a mucosa of the mammal prior to the mammal encountering the contaminated environment or item. By a therapeutically effective amount, it is meant enough to coat the targeted mucosa with enough of the barrier-forming composition to form a barrier that will result in a barrier layer forming on the mucosa. For example, about 100 microliters to about 10 ml, such as, for example, about 1 ml to about 8 ml, or about 2 ml to about 5 ml for a mouthwash formulation, or about 0.125 ml to about 2 ml, such as about 0.5 ml to about 1 ml for a spray formulation. The dosage amount may also be expressed in terms of a volume per square cm, such as, for example, from about 0.5 to about 50 μl/cm2, such as, about 5 to about 40 μl/cm2, or about 10 to about 25 μl/cm2 for a mouthwash formulation; or for a spray formulation, for example, about 0.625 to about 10 μl/cm2, such as, about 2.5 to about 5 μl/cm2. Other delivery mediums, such as dissolvable strips, may have dosages derived from these ranges given the adjustments for concentrations and other factors known to those of skill in the art. In addition, the average thickness of the film formed on the mucosa from the barrier-forming composition may range, for example, from about 0.001 to about 0.2 mm, such as about 0.01 mm to about 0.1, or about 0.08 to about 0.15 mm. For example, for a given human or animal, the therapeutically effective amount can be determined based on the age or weight or size of the mammal to be treated, and the dosage may be those listed above. For non-human mammals, in particular, the dosage amount may be adjusted according to the per square cm values given above and the approximate surface area of the mucosal surface or body cavity to be treated.
In an embodiment, the barrier-forming composition administered in a therapeutically effective amount to a mucosa provides a barrier layer on the mucosa that inhibits the microorganisms from penetrating to the mucosa. In an embodiment, the inhibition of the microorganisms also includes killing or deactivating the microorganism's harmful activity. In an embodiment, the barrier-forming composition blocks and/or kills all harmful microorganisms contacting the barrier-forming composition. In another embodiment, the barrier substantially blocks and/or kills enough harmful microorganisms to prevent them from causing an infectious disease. In the latter case, if the harmful microorganism's penetration of the mucosa is slowed and/or diluted it will enhance the body's own ability to prevent the microorganisms from causing disease or widespread infection. In vitro testing demonstrates that embodiments of the barrier-forming composition prevent all bacteria from reaching the mucosal surface for long periods, including about six hours or more, about sixteen hours or more, and about twenty-four hours or more. In vitro testing shows that in viruses exposed to embodiments of the barrier-forming composition, growth may be inhibited for about two or more days (such as influenza), to about nine days, (such as HIV), after which the viral count is still below the MIC for extended periods, such as about two or three days Inhibitory activity against influenza virus was observed for up to 48 hours.
In vivo testing indicates that embodiments of the barrier-forming composition are therapeutically effective to reduce microbial count in the oral cavity for about six hours or more.
In an embodiment, in a continued dosage method of prevention or treatment, the barrier-forming composition may be administered in a series of doses, such as, for example, about every 1 to 12 hours, about every 2 to 8 hours, or about every 4 to 6 hours. This method of prevention can be continued, for example, for a day or more, such as for about two days to about a week. This continued dosage method may be preferred when the subject is in prolonged contact with a contaminated environment or item. In vivo testing has shown that about 80% of humans following the continued dosage method show a decrease of about 50% or greater of microbial load in the oral cavity over six days of treatment.
The mucosa, may, for example, may be a mucosal surface in the oral cavity, the nasal cavity, or the pharyngeal cavity, such as, the nasopharynx (epipharynx), the oropharynx (mesopharynx), or the laryngopharynx (hypopharynx). The mucosa may also be in the vaginal cavity, stomach, intestine, throat or other orifices of a mammal, including, but not limited to the ear canal.
In an embodiment, administering the composition includes taking the barrier-forming composition in a mouthwash form so as to contact the oral mucosa of the mammal. After a selected amount of time in the oral cavity, e.g. at least about 10 seconds, for example about 15 seconds to about 5 minutes, or about 1 minute to about 3 minutes. Subsequently the composition is discharged from contact with the oral cavity. In another embodiment, the composition is administered by spraying into an oral or nasal orifice of the mammal. Other administration methods include, for example, rubbing or applying a gelled barrier-forming composition onto the mucosa. The barrier-forming composition may be administered to a mammal through many different delivery systems, including, for example: liquids, gels, lubricants, lotions, creams, pastes, aerosolized particles, strips, sprays, rinses, dressings, such as for wound dressings, infusion or layering of the barrier-forming composition into or onto products, such as on condoms, lozenges, or gums. For example, the barrier-forming composition may be administered in the form of a lozenge with a liquid center comprising the barrier-forming composition, or a dissolvable strip comprising the barrier-forming composition.
In an embodiment, the barrier composition may be used to combat transmission of harmful microorganisms from hand-to-mouth or hand-to-nose contact. In this embodiment, the barrier composition is applied to block neutralize or kill microorganisms introduced into a mammal's oral, nasal, or pharyngeal cavity through the mammals hand-to-mouth or hand-to-nose contact. The method includes identifying a contact with a contaminated item by a hand of the mammal, wherein the contaminated item or environment is known, or expected to be, contaminated with harmful viral, fungal, or bacterial microorganisms. This may include contact with the contaminated items or environment listed above.
After such a contact is identified, the hand or both hands that had the contact with the contaminated item may be considered to be contaminated. At this point the barrier composition is administered in a therapeutically effective amount to an oral, nasal, or pharyngeal mucosa of a mammal prior to the mammal's hand-to-mouth or hand-to-nose contact. The barrier-forming composition then provides a barrier on the mucosa that inhibits the microorganisms from contacting the mucosa, and neutralizes or kills the microorganisms.
In an embodiment that illustrates a proposed mechanism of the barrier-forming composition, shown in
In contrast, in a cell treated with the barrier-forming composition, a protective barrier is on the surface of the host cell. The barrier, which is thick enough to cover the cell and any receptors on the cell, prevents the virus particle from binding to the cell receptors. Thus, infection and lysis is also prevented. The barrier-forming composition retains the barrier for a long duration, such as a duration of about 2 hours or more, a duration of about 6 hours or more, a duration of about 16 hours or more, a duration of about 16 hours to about 24 hours, or a duration of about 24 hours or more, thereby protecting host cells and preventing infection. The antimicrobial activity is also retained for a long duration, such as about 2 hours or more, about 6 hours or more, or up to about 24 hours or more, thereby protecting host cells and preventing infection.
Without being bound by theory, the same mechanism described above and depicted in
In an embodiment the barrier-forming composition includes a combination of: a carbohydrate gum, a humectant; and an antimicrobial agent. In an embodiment, the composition meets the following requirements (where C is the carbohydrate gum; H is the humectant; and A is the antimicrobial agent):
about 0.01%≦C≦about 0.4%;
about 4.5%≦H≦about 65%; and
0.050%<A
or
about 0%≦C≦about 0.4%;
about 55%≦H≦about 65%; and
0.050%<A
All percentages are by weight of the total composition.
In an embodiment, the barrier-forming composition includes glycerin or one or more similar humectant substances. The concentration of the humectant may range from about 2% to about 70% weight percent of the entire composition, such as, for example, about 4.5% to about 65%, about 7% to about 35%, or about 15% to about 45%. Humectants similar to glycerin may be classified generally as polyols. The humectants may be, for example, glycerin, sorbitol, xylitol, propylene glycol, polyethylene glycol, and mixtures thereof. In an embodiment, glycerin may be used at high concentrations such as about 55 to about 65% in the absence of a gum.
In an embodiment, the composition also includes a gum. The gum may be, for example, a polysaccharide, xanthan gum, gum Arabic, or guar gum. Such gums may be generally classified as carbohydrate gums that have an overall negative charge. In another embodiment, the gum may be, for example, xanthan gum, guar gum, gum Arabic, tragacanth, gum karaya, locust bean gum, carob gum, and pectin. These gums may also be generally classified as carbohydrate gums that have an overall negative charge. The gum may be present in a weight percentage of the total composition ranging from about 0.01% to about 0.4%, such as for example, about 0.25% to about 0.35%, about 0.05% to about 0.25%, or about 0.4%.
In an embodiment, an antimicrobial agent is present in the composition. For example, the composition may include one or more anti-viral agents, or antifungals. In addition, the effect of such antimicrobials includes static and/or cidal activity.
The antimicrobial agent may include, but is not limited to cationic antimicrobial agents and pharmaceutically acceptable salts thereof, including, for example, monoquaternary ammonium compounds (QAC, cetrimide, benzalkonium chloride, cetalkonium chloride, cetylpyridinium chloride, myristalkonium chloride, Polycide), biquaternaries and bis-biguanides (Chlorhexidine, Barquat, hibitane), and biguanides, polymeric biguanides, polyhexamethylene biguanides, Vantocil, Cosmocil, diamidines, halogen-releasing agents including chlorine- and iodine-based compounds, silver and antimicrobial compounds of silver, peracetic acid (PAA), silver sulfadiazine, phenols, bisphenols, hydrogen peroxide, hexachloroprene, halophenols, including but not limited to chloroxylenol (4-chloro-3,5-dimethylphenol; p-chloro-m-xylenol).
In addition, the antimicrobial may also be or include: antibacterial agents, both cidal and static, and different classes, for example tetracycline, chloramphenicol, fusidic acid, fluoroquinolone, macrolide antibacterial agents, oxazolidinones, quinolone- and naphthyridone-carboxylic acid, citral, trimethoprim and sulfamethoxazole (singly and combined), aminoglycoside, polymyxin, penicillins and their derivatives. In addition, the antimicrobial may also include, for example: antifungal agents in the following classes: azoles, polyenes, echinocandins, and pyrimidines. Combinations of the any of the foregoing antimicrobial agents are also contemplated. Many of the foregoing are cationic species or their pharmaceutically acceptable salts, and in an embodiment, cationic antimicrobials are utilized in the composition.
The antimicrobial may be present, for example, in an amount ranging from about 0.05% to 0.1% by weight of the total composition, such as, for example, about 0.05% to about 0.6% or about 0.6% to about 0.1%. In an embodiment, the antimicrobial is about 5% or less, or about 3% or less, or about 1% or less, such as when the antimicrobial used does not cause solubility problems at higher concentrations.
In embodiments, the composition may further include other components, such as, for example, copovidone and other lubricating agents, parabens such as methyl paraben or propylparaben, flavoring agents, preservatives, such as sodium benzoate, buffering agents, such as monosodium and disodium phosphate, and carboxymethylcellulose. These components may, for example, be included in amounts ranging from about 0.01% to about 5% by weight of the total composition, such as, for example, about 0.1% to about 2%. Flavoring agents may also be used. Buffering agents (such as monosodium or disodium phosphate) may be used to tailor the composition to the pH of the body cavity treated
Purified water may be used as the diluent component of the composition.
In an embodiment, the composition can also function to create a retained benefit through the inclusion of additional components providing additional beneficial activity, such as, for example, probiotics, antacids, vitamins, drugs, nutraceuticals, silver, natural or synthetic small molecules, anti-oxidants, or immunostimulators, and combinations thereof. In an embodiment, silver may be used as the antimicrobial.
Some antimicrobials, including cetyl pyridinium chloride, are known to be negatively affected in their antimicrobial properties by additional active components. Thus, in an embodiment, the composition consists essentially of the gum, the humectant, and the antimicrobial. In an embodiment, the composition is exclusive of agents for acting against the teeth and/or gums, including, for example, teeth whitening or desensitizing agents. In an embodiment, the composition is also exclusive of cellooligosaccharides. In an embodiment, the composition is exclusive of one or more of time-release agents, allergy-relief compounds, azelastine, silicon based oils, essential oils, polyvinyl pyrrolidone, and potassium nitrate. For the avoidance of doubt, none of the above should be construed to mean that all embodiments are exclusive of these compounds.
In general, the dual-action mechanism of providing a barrier from microorganisms to the mucosa and an antimicrobial agent provides a long-lasting effect, characterized by both in vitro. Simulated in vivo, and in vivo examples below. In in vivo examples the barrier-forming composition was shown to have antimicrobial effect (cidal or static) for at least 6 hours, while the barrier property was not tested in actual human tests, simulated in vivo tests (on artificial human mucosa EHOMs) indicated the barrier itself had a significantly extended duration past 6 hours, such as greater than about 8 hours, about 6 to about 16 hours, and about 24 hours, or more. In addition, in vitro tests indicate the antimicrobial effect had a significantly extended duration past 6 hours, depending on the microorganism tested, such as greater than about 8 hours, about 6 to about 16 hours, and about 24 hours, or more.
Post antimicrobial effect (PAE) is defined as suppression of microbial growth that persists after limited exposure to an antimicrobial agent. Having a longer PAE is considered advantageous for antimicrobial agents as it allows for persistent inhibition of microbial growth, and may affect dosing regimens as agents with long PAEs may need less frequent administration than those with short PAEs.
In embodiments of the method and composition disclosed herein the PAE of the composition when applied to a mucosa has a PAE that persists for about 6 hours or more, such as about 6 hours to about 16 hours, or about 16 hours to about 24 hours.
In an embodiment, the composition has a Weybridge viscosity of about 16 to about 20 cps, such as, for example, about 17 to about 19 cps.
In an embodiment, at least a portion of the composition is ingested and is safe for human consumption in the therapeutically effective dosage.
It should be noted that not all mucosa in the treated cavity (e.g. oral, nasal, pharyngeal, or other) need to be covered with the barrier-forming composition, in order for the composition and method to be effective. In such a case, the composition and method are still effective to reduce microbial load in the cavity. Without being bound to theory, due to the trapping and killing dual-action mechanism, the barrier-forming composition will trap and kill microbes that otherwise would pass over the composition to reach any uncovered portions of the cavity in which the composition is applied. That said, the applied composition should be effective to cover a substantial percentage of the mucosal surface in the treated cavity, such as, for example, about 50% or more of the cavity, such as about 75% or more, or about 90% or more.
Without being bound by theory, the barrier-forming composition is not hydrophilic which allows the barrier-forming composition to have a greater affinity to adhere to and cover the mucosal surface. Furthermore, in an embodiment, the antimicrobial being embedded in the non-hydrophilic composition will allow for sustained antimicrobial activity in the mucosal environment. In an embodiment the barrier-forming composition is amphiphilic or has amphiphilic components.
One measure of hydrophilicity is the Rf (relative front) value, determined by chromatography in water. In an embodiment, the composition has an Rf value in water of 0 to about 0.25, such as about 0.0001 to about 0.15, or about 0.03 to about 0.1.
In an embodiment, the composition has a pH of about 4 to about 8, such as about 5 to about 7, or about 6 to about 7.5. The pH can be tailored to be compatible with the mucosa to be treated.
As the Examples below show, the barrier-forming composition has been shown to block the passage of a wide variety of representative bacteria and viruses. Because viruses are amongst the smallest infectious microorganisms, and because the barrier-forming composition forms a mechanical barrier blocking viruses from the mucosal cells, it is expected that the barrier-forming composition would be an effective preventative treatment not only for viruses but also for larger microorganisms, including a wide range of bacteria and fungi.
Several experiments were performed to assess the safety of the composition on mammals and the ability of the spray formulation to form a protective barrier on an Engineered Human Oral Mucosa (EHOM) model. The experimental evidence showed that the composition formed a barrier over tissues, which prevents microorganisms from penetrating into the tissues
Normal human gingival cells (epithelial cells and fibroblasts) were obtained from ScienCell Research Laboratories (Carlsbad, Calif., USA). The fibroblasts were cultured in Dulbecco's modified Eagle's medium (DME, Invitrogen Life Technologies, Burlington, ON, Canada) supplemented with fetal bovine serum (FBS, Gibco, Burlington, ON, Canada) to a final concentration of 10%. The epithelial cells were cultured in Dulbecco's modified Eagle's (DME)-Ham's F12 (3:1) (DMEH) with 5 μg/mL of human transferrin, 2 nM 3,3′,5′ of tri-iodo-L-thyronine.
0.4 μg/mL of hydrocortisone, 10 ng/mL of epidermal growth factor, penicillin and streptomycin, and 10% FBS (final concentration). The medium was changed once a day for epithelial cells and three times a week for fibroblasts. When the cultures reached 90% confluency, the cells were detached from the flasks using a 0.05% trypsin-0.1% ethylenediaminetetra acetic acid (EDTA) solution, washed twice, and resuspended in DMEM (for the fibroblasts) or DMEH-supplemented medium (for the epithelial cells).
The EHOM model was produced by using the gingival fibroblasts and epithelial cells of Example 1 that were used to form a complex three-dimensional spatial cellular organization similar to that found in normal human oral mucosa. The lamina propria was produced by mixing Type I collagen (Gibco-Invitrogen, Burlington, ON, Canada) with gingival fibroblasts, followed by culture in 10% FBS-supplemented medium for four days. The lamina propria was then seeded with gingival epithelial cells to obtain the EHOM. The tissue specimens were grown under submerged conditions until the total surface of the lamina propria was covered with epithelial cells. To produce stratified epithelium, the EHOM was raised to an air-liquid interface for four more days to facilitate the organization of the epithelium into its different strata.
The lamina propria is a thin layer of loose connective tissue that lies beneath the epithelium and together with the epithelium constitutes the mucosa.
Examples of the barrier-forming compositions were created by adding the ingredients listed below in a 50-mL centrifuge tube, and vortexing to bring to “free-flow” consistency. The constituents of the compositions and their approximate amounts are given in Table I (the values in Table I are percentages by weight of the total composition):
Based on the results below, the preservatives were found to be superfluous to the barrier formation and antimicrobial activity.
Wound repair assays were performed on the epithelial cells and fibroblasts of Example 1. Briefly, gingival epithelial cells (1×104 cells) and fibroblasts (1×103 cells) were seeded into wells of 6-well plates and grown in Dulbecco's modified Eagle's (DME)-Ham's F12 (3:1) (DMEH) with 5 μg/mL of human transferrin, 2 nM 3,3′,5′ of tri-iodo-L-thyronine, 0.4 μg/mL of hydrocortisone, 10 ng/mL of epidermal growth factor, penicillin and streptomycin, and 10% FBS (final concentration). Upon confluency, wounds were made in the confluent monolayer of each well using a 200 μL pipette tip.
In Examples 11 and 12, the epithelial cell cultures from Example 10 were exposed to diluted barrier-forming compositions of Examples 3 and 4 for about 2 minutes. In Examples 13 and 14, the fibroblast cultures from Example 10 were exposed to diluted barrier-forming compositions of Examples 3 and 4 for about 2 minutes. Prior to exposure, Example 3 was diluted with saline to a 1% concentration and Example 4 was diluted with saline to a 5% concentration. Following exposure, the spray was washed out twice with warm sterile culture medium, then cell cultures were over layered with DME for fibroblasts and DMEH for epithelial cells, and cultured for 6 and 24 hours in a 5% CO2 humid atmosphere at 37° C. Control Example 15, which was an untreated culture from Example 10, was also tested.
Wound repair/cell migration was ascertained using an optical microscope, and digital photographs were taken (Nikon, Coolpix 950). The percentages of wound closure (cell growth/migration) were calculated by comparing relative wound areas before and after exposure to our barrier spray using formula I:
Following contact with the barrier-forming compositions, epithelial cells (
This experiment was repeated five separate times with similar results. The treated Examples 11 and 12 did not show a major side effect on gingival epithelial cells growth/migration nor on cells differentiation (no cells presenting large cytoplasm and large nucleus).
The engineered human oral mucosa (EHOM) model of Example 2 was used to determine whether the composition of Examples 10 and 11 were safe and did not promote tissue damage or cell necrosis. In Example 16 and 17, the epithelium surface (10 cm2) was over layered with a thin layer (300 μl) of the Example 3 barrier-forming composition at a dilution of 5% and the Example 4 composition at a dilution of 1% (both were diluted in serum free culture medium) for time periods of about 2 minutes. The variation in time period was not deemed to have an effect on the results and just reflects the time it took to conduct the procedures. Control Example 18 was a control that was not treated with the barrier-forming composition. The EHOM tissues were then rinsed twice with warm sterile culture medium and incubated in a 5% CO2 humid atmosphere at 37° C. for 24 hours. Following this incubation period, to assess whether the engineered tissue was damaged, each EHOM was macroscopically examined for the presence of holes due to the contact with the barrier spray formulation. Photos were taken of these EHOM to confirm such possibility. Additionally, biopsies were collected from each EHOM and subjected to histological staining using eosin and hematoxylin.
In Examples 16 and 17, EHOM exposed to Examples 3 and 4 in the 1 and 5% dilutions, similar to untreated control Example 18, do not show any macroscopic damage such as holes. (See
The same observation was noted in an Example 19, which was the same as Example 16, except it included an EHOM treated with a 1% dilution (data not shown).
Side effects, if any, of the barrier spray composition on EHOM injury was also assessed by measuring the leakage of intracellular LDH into the culture medium.
In Examples 20-23, EHOM tissues were exposed to (A) 1% or (B) 5% dilutions of Examples 3 and 4, respectively, for 10 minutes, followed by growth in culture medium for 24 hours. Examples 24 and 25 were controls that were not treated. 50 μl of a supernatant of each of Examples 20-25 were then transferred to a sterile 96-well flat-bottom plate. Each well was supplemented with 50 μl of reconstituted substrate mix, and the plate was incubated for 30 min at room temperature in the dark. To estimate LDH levels, aliquots of the culture supernatant were collected and subjected to an LDH cytotoxicity assay (Promega, Madison, Wis., USA), as per the manufacturer's protocol. This assay measures the conversion of L-lactate and NAD to pyruvate and NADH by the released LDH. To stop the reaction, 50 μl of stop solution was added to each well. Next 100 μl of the mixture were transferred to a 96-well flat-bottom plate, and the absorbance was read at 490 nm with an X-Mark microplate spectrophotometer (Bio-Rad, Mississauga, ON, Canada).
In the LDH and wound repair experiments, the following test methods were used. Each experiment was performed at least four times, with experimental values expressed as means±SD. The statistical significance of the differences between the control (absence of barrier spray) and the test (presence of spray) values was determined by one-way ANOVA. Posteriori comparisons were done using Tukey's method. Normality and variance assumptions were verified using the Shapiro-Wilk test and the Brown and Forsythe test, respectively. All of the assumptions were fulfilled. P values were declared significant at ≦0.05. Data were analyzed using the SAS statistical package (version 8.2, SAS Institute Inc., Cary, N.C., USA).
Results presented in
EHOMs of Example 2 were treated with Example 4 for about 2 minutes, washed with culture medium then cultured for 24 hours. Tissue was then examined for possible macroscopic tissue damage (presence or not of holes). Tissue damage was also investigated by histological analyses. For this purpose, biopsies were taken from each EHOM. They were fixed with 4% paraformaldehyde solution and then embedded in paraffin. Thin sections (4 μm) were stained with eosin-hematoxilyn. Sections were mounted with a coverslip in 50%-glycerol mounting medium, observed through an optical microscope, and photographed. No damage to the treated EHOMs was ascertained.
In Examples 27 and 28, two approaches were used to determine whether the control Examples formed a barrier that blocked the microbial passage through the mucosal tissues and also had an inherent anti-microbial effect. Growth in pass-through chamber and growth on EHOM surface was assessed by evaluating growth in agar media.
In Example 27, EHOMs of Example 2 were put in contact with 1 and 5% dilutions (diluted in serum free culture medium) of Example 4 for 2 minutes. Tissues were then washed twice with serum free culture medium then over layered with 1×106 candida microbial cells in a volume of 300 μl. Tissues were then put on air-liquid culture plates and incubated for 24 hours in 5% CO2 humid atmosphere at 37° C. Next, the culture medium underneath the EHOM (ventral chamber) was collected and seeded on Sabouraud agar plate to verify whether or not the microorganisms penetrated through the tissue and reached the culture medium below. A culture was also obtained from the EHOM surface and seeded on Sabouraud agar plate. The process is graphically depicted in
In Example 28, EHOMs of Example 2 that were treated with 1 and 5% dilutions of the Example 4 composition for 2 minutes were over layered with candida microbial cells for 24 hours were flipped onto Sabouraud dextrose agar plates and left in place for 5 minutes. The EHOMs were then removed and the plates were incubated for 24 hours at 30° C., after which microbial growth was ascertained macroscopically and photographed. Each experiment was repeated 5 independent times with similar results.
In Examples 29 and 30, Examples 27 and 28 were repeated, except the EHOM were infected with S. mutans. Similar results were obtained that indicated that the barrier-forming compositions formed a barrier preventing the S. mutans microbes from passing through the barrier, but did not have an antimicrobial effect.
In Example 32, a set of EHOM tissues from Example 2 was treated with the barrier-forming composition of Example 4 and then overlaid with C. albicans. In control Example 31 a control set was not treated with the barrier-forming composition prior to overlayering with C. albicans. Immediately after each contact period, biopsies were taken from each EHOM, fixed with paraformaldehyde solution, and embedded in paraffin. Thin sections (4 μm) were stained with eosin-hematoxylin. Sections were observed using an optical microscope to analyze the invasion/penetration of microbial cells into the tissue. Following microscopic observations, representative photos were taken from each condition and presented. The experiment was repeated three times with similar results. Similar results were also obtained with treatment with Example 3 (data not shown).
The EHOM model described above was also used to evaluate the ability of Examples 5-7 to form a barrier that: (a) prevents oral bacteria (S. mutans) and fungi (Candida albicans) from penetrating/invading human oral mucosa, and (b) does not cause damage to host cells (cytotoxicity assay).
Examples 33-40 were formulated according to Table III below.
C. albicans
C. albicans
C. albicans
C. albicans
S. mutans
S. mutans
S. mutans
S. mutans
In Examples 33-40, after pre-treatment and incubation according to the procedures of Examples 27 and 28: (1) the flow-through medium was collected from the lower chamber; and (2) tissues were flipped and placed onto the surface of Sabouraud dextrose agar Petri dishes, and incubated for 24 hours. Collected flow-through media were spread onto agar media plates, and incubated for 24 hours also as described in Examples 27 and 28. Table III also indicates the Figure in which a photo of each Example was taken showing the microbial growth on each flipped Example culture.
In Examples 41-47, the EHOM model was used to assess the toxicity of the composition. Examples 41-47 were formulated as stated in Table IV.
C. albicans
C. albicans
C. albicans
C. albicans
S. mutans
S. mutans
S. mutans
S. mutans
After pre-treatment and incubation according to the procedures of Examples 27 and 28, culture supernatant was collected from the Example 41-48 EHOM tissues and used to measure LDH activity.
As shown in
Data are mean±SD and were computed as stated in Example 25 above. No significant difference between untreated and treated tissues was noted.
Taken together, the data indicates that the example compositions represent an effective and a safe barrier that can prevent microorganisms from penetrating and invading human mucosal tissues.
Preclinical evaluation of the barrier-forming composition showed that the composition was effective against many bacteria and yeasts. The antimicrobial activities of the Example 7 barrier-forming composition were evaluated against a number of clinical isolates obtained from patients, including S. salivarius, P. gingivalis, S. pyogenes, S. pneumonia, Fusobacterium nucleatum, S. mutans, S. aureus, Y enterocolitica, S. oxalis, S. mitis, C. albicans, C. krusei, C. tropicalis, and C. glabrata. Activity of the Example 7 barrier-forming composition was evaluated by determining its minimum inhibitory concentration (MIC) using reference methods described in the Clinical and Laboratory Standards Institute (CLSI) documents M07-A8, M11-A7, and M27-A3.
A standardized inoculum of several types of aerobic or anaerobic bacteria (1×104 cells/ml) was incubated with serially diluted solutions of Example 7 (containing 0.1% CPC, or 1 μg/ml) or 2% chlorhexidine gluconate (CHX, 20 μg/mL) as a comparative example. Cells were allowed to grow in the presence or absence (growth control) of the test agents for 24 hours. The MIC for each agent was defined as the concentration that induced a 100% growth inhibition (compared to no-drug control).
A similar microdilution-based CLSI method (M27-A2) was used to evaluate the activity of Example 7 against albicans and non-albicans Candida species.
S. salivarius
P. gingivalis
S. pyogenes
S. pneumonia
F. nucleatum
S. mutans
S. aureus
Y. enterocolitica
S. oralis
S. mitis
C. albicans
C. krusei
C. tropicalis
C. glabrata
The barrier-forming composition was also found to have potent antimicrobial activity against: MRSA, Acinetobacter baumannii, Streptococcus sanguis, S. gordonii, and Aggregatibacter actinomycetemcomitans.
As can be seen in Table V, the Example 7 composition exhibited potent activity against many aerobic and anaerobic bacteria, as well as the fungi.
The MIC of the Example 7 barrier-forming composition against S. oralis and S. mitis was noticeably elevated (500 μg/mL) compared to other organisms. It is interesting to note that S. oralis and S. mitis are normal commensals of the oral cavity. Activity of the commonly used antimicrobial chlorhexidine (2% solution) was also determined by the same method. Table V shows the MIC of the Example 7 barrier-forming composition and chlorhexidine (2% solution) as a comparative example against various microorganisms.
Taken together, these results demonstrate that Example 7 possesses potent activity against pathogenic bacteria and fungi commonly isolated from the oral cavity. This activity was more potent than that observed for chlorhexidine.
A similar activity profile was observed for the barrier-forming compositions of Examples 10 and 11.
As a further comparison, published data shows that the tested barrier-forming composition has a better or at least equivalent MIC compared to CPC alone (i.e. not in a composition according to the barrier formulation disclosed herein). See Frank-Albert Pitten and Axel Kramer, “Efficacy of Cetylpyridinium Chloride Used as Oropharyngeal Antiseptic,” Arzneim.-Forsch./Drug Res. 51 (II), pp 588-595 (2001), which is incorporated herein by reference. The data varies based on the microorganism tested, but, for example, CPC (alone) against S. mutans has an MIC of 5.0-6.25 μg/mL, which is much less effective than the 1.95 μg/mL reported in Example 53. This was an unexpected result since CPC has the risk of losing its activity when mixed with other excipient chemicals in a formulation. See Department of Health and Human Services (Food and Drug Administration) (1994) Oral Health Care Drug Products for Over-the-Counter Human Use; Tentative Final Monograph for Oral Antiseptic Drug Products. Proposed Rules (21 CFR Part 356, Docket No. 81N-033A, RIN 0905-AA06). Federal Register 59:6084-124.
The PAE of Example 8 against several microorganisms was evaluated in Examples 63-68. Control Example 69 was also provided. Several microorganisms were exposed to Example 8 (at a concentration equal to the MIC) for 1 min followed by three washes to remove residual formulation. The treated cells were then spread on agar medium plates, which were incubated at 37° C., and the time taken for the cells to regrow was determined. PAE was expressed as the time (in hours) for which growth inhibition (%) was maintained by the Examples 63-68, compared to the untreated control Example 69.
As shown in
Testing of PAE for the Example 7 barrier-forming composition against S. mutans compared to a similar comparative Example with lower CPC content showed that the PAE of Example 7 was 24 hours, while that of Comparative Example 70 was 6 hours. Thus demonstrating the Example 7 exhibits greater prolonged antimicrobial activity than comparative Example 70, and that additional amounts of CPC have more than a simple additive effect on anti-microbial activity.
Scanning electron microscopy was also used to show that treatment of S. sanguis, (Example 71), S. oxalis, (Example 72), and C. albicans (Example 73) with the composition of Example 3 resulted in destruction of cellular integrity.
In Examples 71-73, cells were grown in the presence of Example 3 for 24 hours. Next, the cells were washed to remove residual formulation, dehydrated by passing through a series of alcohol solutions (10% to 100%, v/v) and processed for SEM analysis. Control Examples 74-76 differed from Examples 71-73 in that they were not grown in the presence of Example 3.
The SEM photos showed that unlike untreated control Examples 74-76, which demonstrated healthy intact cells (
Since biofilms are precursors to certain infectious diseases, in Examples 77-79, experiments were performed to determine whether the barrier-forming compositions can prevent formation of biofilms by bacteria and yeasts. Biofilms were formed using an in vitro model. See Chandra et al. “In vitro Growth and Analysis of Candida Biofilms” Nature Protocols 3(12): 1909-1924 (2008).
In Examples 77-79 a standard biofilm model was employed to determine whether the Example 3 barrier-forming composition exhibits activity against bacterial and fungal biofilms. In Examples 77-79, three different microorganisms (C. albicans, S. oralis, and S. salivarius) were adhered on substrate for 90 minutes to allow biofilms to form to adhesion phase. Next, discs containing the adherent bacteria were incubated for 15, 30 or 60 minutes with 50% concentration of Example 3 (1:1 dilution with appropriate medium). Following incubation, biofilms were scraped, spread on culture media, incubated and colony forming units (CFUs) were determined. Media diluted with phosphate buffered saline (PBS, 1:1) were used as a control. Table VI reports data at 0 (Control), 15, 30, and 60 minutes.
C. albicans
S. oralis
S. salivarius
In Example 80 we evaluated the effect of 1 minute exposure of C. albicans early phase biofilms to Example 3, and found that even with an exposure for as short a time as 1 minute, it was able to inhibit biofilm formation (
To determine whether the barrier-forming composition can treat biofilms, we evaluated its activity against fully formed mature biofilms. Biofilms were grown to mature phase, and then exposed to Example 7 for 2 or 4 hours, and the resulting CFUs were determined. A composition that causes at least 2-log reduction in microbial CFUs compared to untreated cells is considered to be effective against microbial biofilms.
As shown in Table VII, exposure to Example 7 resulted in complete eradication of biofilms formed by C. albicans and S. oxalis, and a 3.4-log reduction in CFUs for biofilms formed by S. salivarius compared to the untreated control (log CFU=3.95 vs. 7.36, respectively).
C. albicans
S. oralis
S. salivarius
In summary, the results indicate that Example 15 possesses potent activity against biofilms formed by bacteria and fungi.
The activity of barrier-forming composition against viruses, including respiratory viruses (influenza virus H1N1, strain 2009/H1N1/infA) and the human immunodeficiency virus (HIV) was determined.
The Barrier-Forming Composition Inhibits the Infectivity of Influenza A
To evaluate the effect of the barrier-forming composition on the infectivity of influenza virus, Madin Darby canine kidney (MDCK) cells were grown to ≧90% confluence at 37° C. prior to infection. MDCK cells are used routinely for assays involving influenza viruses.
In Example 85 cell monolayers were exposed to the Example 7 barrier-forming composition. In control Example 86 the cell layers were exposed to optiMEM (+P/S, +Lglu) tissue culture media for different times: (1) T1: 30 min exposure, (2) T2: 1 h exposure, (3) T3: 2 h exposure. Next, the formulation was removed and the cell monolayers were infected with influenza virus (multiplicity of infection (MOI)=0.1). Cells that were untreated or infected immediately after exposure (T0) were used as baseline controls. Infected cells were then centrifuged, resuspended in 500 μl of growth medium, and incubated at 32.5° C. for 48 hours. Immunofluorescence microscopy (using FITC labeled anti-influenza antibody) was also used to evaluate the effect of the Example 7 barrier-forming composition on the ability of influenza virus to infect mammalian cells.
The data showed that exposure of cell monolayers to Example 7 for 30 minutes, 1 hour, or 2 hours remained confluent and healthy (Example 85). In contrast, in the untreated cells and cells treated immediately prior to infection (T0) (control Example 86) demonstrated substantial cytopathic effect. As seen in
Further fluorescence microscopy images corresponding to Examples 85 and 86 are presented in
Cell culture supernatants from the same assay as in Examples 87 and 88 were collected and nucleic acid extracted using QIAamp Viral RNA Kit (QIAGEN, Valencia, Calif.). Random hexamer primers (Invitrogen Carlsbad, Calif.) were used to create a cDNA library for each specimen. Reverse transcription reactions were performed with M-MLV RT (Invitrogen, Carlsbad, Calif.) according to the manufacturer's specifications. Quantitative analysis was performed on a StepOne Plus Taqman Real Time PCR (Applied Biosystems, Branchburg, N.J.) using TaqMan Universal PCR Master Mix (Applied Biosystems, Branchburg, N.J.), 2 μl of cDNA sample, and primers/probes targeting the influenza matrix gene. A reference standard was prepared using a cDNA fragment of the H1N1 matrix gene and human RNAse P amplified by conventional RT-PCR, gel purified (QIAquick, Qiagen, Valencia, Calif.), and quantified using a spectrophotometer (Beckman Coulter, Brea, Calif.).
As shown in
To determine whether the barrier-forming composition has direct antiviral activity against influenza virus, we infected African Green Monkey Kidney (CV-1) cells (grown in 24-well plates to 90% confluence) with influenza virus that was pre-treated with Example 7. CV-1 cells are routinely used a highly susceptible substrate for diagnosis and study of viruses.
In Examples 89-91, a standardized amount of influenza (0.1 MOI) was pretreated for 5 minutes at room temperature with: (1) Example 7 (to form Example 89), (2) control Example 6, a compound without CPC but with preservatives (to form Example 90), and (3) control Example 5 placebo alone (a compound without CPC and preservatives) (to form Example 91). After the 5 minute incubation virus/drug mix was diluted by an additional equal volume with optiMEM (+P/S, +Lglu) to dilute out the treatment compositions.
In Examples 89-91, CV-1 cells were prepared as described in above. The Example 89-91 treated and untreated viruses were then inoculated onto the cells as described above.
Influenza viral load was determined by real time PCR as described above. The data as shown in
These results demonstrate that the Example 7 barrier-forming composition possesses direct antiviral activity against influenza virus that is not inherent in Examples 5 and 6.
In Examples 92 and 93, the barrier-forming composition's ability to inhibit the infectivity of influenza A (2009/H1N1/infA) was tested. African Green Monkey Kidney (CV-1) cells were grown in 24-well plates to 90% confluence. Next, the barrier-forming composition, Example 7, was applied to the cells (20% Example 7, 80% OptiMeM, working CPC concentration of 0.02%.) in Example 92. Each time point matched with control Example 93 (No barrier-forming composition applied, 100% OptiMeM). The barrier-forming composition was allowed to dwell on the surface for 30 minutes, and then removed from the ceil monolayer. Cells were thoroughly washed twice with sterile optiMEM (+PfS, +Lglu). Influenza was inoculated at MOi=0.1 at 30 minute intervals from TO through T+6 hours. Following infection, cells were then centrifuged @ 2200 rpm×30 minutes and 500 μl of optiMEM (+P/S, +Lglu, 2 μg/ml trypsin (sigma-Aldrich, St Louis, Mo.)) was applied. Infected cells were grown at 32.5° C. for 96 hours at 5% CO2. The influenza viral load was determined by real time PCR.
As shown in
Examples 70-72 determined whether the barrier-forming composition possessed activity against HIV. Host MT mammalian cells were plated into 96-well round bottom plates at a density of 15,000 cells/well in RPMI/10% FBS/PS. The next day (Day 2), virus was pretreated with control Example 5 (to form Example 94), control Example 6 (to form Example 95), or Example 7 (to form Example 96) for 5 minutes and added to cells. After 24 hours of exposure to formulation, the MT (macaque) mammalian cells were washed 3 times with phosphate buffered saline (PBS) and fresh media was replaced. Supernatant (10 μL) was collected post-treatment on Days 1, 2, 5, 6, 7, and 9, and the viral load was determined by reverse transcriptase (RT) activity.
The results showed that Example 7 in Example 96 exhibited anti-HIV activity at all time points monitored post-treatment.
The control Example 5 or control Example 6 without CPC and/or preservative in Examples 94 and 95 exhibited only minimal anti-HIV activity.
In summary, our findings demonstrate that the barrier-forming composition Example 7 containing CPC exhibits long-lasting antiviral activity against HIV.
Representative organisms viral lesions are important infections in different mucosal tissues. In Example 97 an experiment was performed to determine whether the barrier-forming composition exhibits activity against the common oral Epstein-Barr virus (EBV). Western blotting was used to evaluate the ability of the Example 8 barrier-forming composition to degrade lytic viral protein EAD (indicating inhibition of viral replication).
In Examples 97, EBV-infected gastric epithelial cells were exposed to different dilutions (1:16, 1:32 and 1:64) of Example 8, and the presence of EAD protein was detected using specific antibodies. Presence of cellular β-actin was used as an indicator of epithelial cell integrity. As shown in
To determine the duration for which the barrier-forming composition can maintain the antimicrobial activity, bacteria and fungi were exposed to an EHOM of Example 2 that was treated with the barrier-forming composition of Example 7 in a well and an EHOM of Example 2 that was treated with a comparative commercial product in a well for 2 minutes. The bacterial and fungal microbes were overlaid on top of the control untreated EHOM (Example 98) and the treated EHOMs (Example 99 and Comparative Example 100). Next the residual (flow-through) solution was removed from the bottom well (lower chamber of the EHOM model) and spread onto agar medium plates.
In control Example 98 an untreated EHOM was tested. In Example 99 S. mitis bacteria was overlaid on the barrier-forming composition as described above. Example 100 is a comparative example showing the activity of commercially available LISTERINE (containing ethanol (26.9%), menthol, thymol, methyl salicylate, and eucalyptol) against S. mitis bacteria. Table IX shows the results.
In Examples 101-103, the same procedure of Examples 98-100 was performed except Candida albicans fungus was tested on the barrier-forming composition as described above. Table X shows the results. Example 103 is comparative, showing the activity of commercially available LISTERINE.
The data further showed that Example 7 barrier-forming composition maintained activity for up to and including 24 hours. Taken together, these results showed that unlike LISTERINE, the Example 7 barrier-forming composition continued to maintain an intact barrier on EHOM tissues for up to and including 24 hours.
To identify further examples of concentrations of glycerin and xanthan gum that can form a barrier effective in preventing the passage of microorganisms, different concentrations of the gum xanthan gum and humectant glycerin were tested (5%-95% glycerin; 0.005%-0.5% xanthan gum) singly and in combination using an in vitro filter insert-based barrier model.
Filter inserts of 3 μm and 8 μm diameter pore size were used for testing the passage of bacteria (Streptococcus salivarius) and fungi (Candida albicans), respectively. Glycerin or xanthan gum or their combinations (100 μL aliquots) were overlaid on the surface of the filter to form a barrier. The filter had a diameter of 24 mm. Thus, the film had a thickness of approximately 0.01 mm on the filter, mimicking a value in the range of thicknesses of the composition film when applied in a therapeutically effective amount to the mouth. Next, 5×104 cells of either bacteria or fungi were applied on top of the formed barrier in the filter inserts. Next, we placed these filter inserts on the surface of agar medium (Brain Heart Infusion (BHI) medium for bacteria, Sabouraud Dextrose (SD) medium for fungi) in 6-well plates. The plates along with the filter inserts were incubated overnight for 24 hours at 37° C.
The plates were monitored for the presence of bacterial or fungal growth CFUs (colony forming units) in the agar medium as well as in the filter insert. Microbial growth in the filter insert only, but not in the agar medium, demonstrated that an effective barrier was formed on the filter, which prevented passage of microorganisms. Conversely, growth in the agar medium around the filter insert suggested that the tested agents failed to form an effective barrier, allowing the organisms to go through the filter.
The results reported in Table XI showed that glycerin was able to form a barrier at concentrations greater than or equal to 55%, when tested alone. In contrast, xanthan gum alone did not form a barrier at any of the concentrations tested (ranging from 0.005% to 0.4%). However, it was observed that when combined with 0.01% xanthan gum, a barrier was formed at glycerin concentrations 7%, 45%, 55%, and 65%. Furthermore, combination of 0.4% xanthan gum with glycerin concentrations of 7%, 15%, 25%, 35%, 45%, 55%, and 65% also formed a barrier. Therefore, specific combinations of glycerin and xanthan gum were identified that can form a barrier that prevents passage of microorganisms in an in vitro filter insert-based model.
Microbial cells retained by the compositions of Examples 104-153 formed on filter inserts were trapped by the barrier, and were viable, thus demonstrating that the formed barrier does not have an inherent antimicrobial property without an antimicrobial agent. In other words, the microbes retained in the barrier were still active and could pose a threat to infection; for example, if they are freed from the barrier by abrasion or after the barrier loses its integrity.
In addition to the Examples above on EHOM samples, further testing was performed to further demonstrate the barrier-forming composition (a) does not damage the host tissues, and (b) is able to prevent microbial invasion into the human mucosal tissues. These criteria were tested for two representative combinations (glycerine:xanthan gum; 7%:0.01% and 35%:0.4%), selected based on the in vitro results of Examples 104-153, because they successfully formed a barrier. Formulations containing these two combinations were tested using the EHOMs of Example 2 that mimic the mucosal lining.
The EHOMs were treated with the various formulations of Examples 3 and 4 in either 1% (Examples 154 and 155) or 5% (Examples 156 and 157) dilutions in normal saline [0.9%]) for about 2 minutes to form Examples 154-157. Each EHOM was covered with 300 μL of one of the tested formulations and left under the sterile hood for 10 minutes at room temperature (25° C.). At the end of the contact period, tissues were washed twice with culture medium to remove the formulations.
After treatment with Examples 3 and 4, the EHOMs were then examined for possible macroscopic tissue damage (presence of holes). Tissue damage was also investigated by histological analyses. For this purpose, biopsies were taken from each EHOM and fixed with 4% paraformaldehyde solution and then embedded in paraffin. Thin sections (4 μm) were stained with eosin-hematoxilyn and mounted with a coverslip in 50%-glycerine mounting medium, observed through an optical microscope, and photographed. The treated EHOMs and a control untreated EHOM were examined for macroscopic tissue damage and structural changes. There was no visible damage (holes) in the untreated or treated tissues at a magnification of ×500 in five different EHOMs tested.
The Example 156 and 157 EHOMs that were treated with the 5% dilution of Examples 3-7 of the barrier-forming composition were then over-layered with 1×106 cells of either C. albicans or S. mutans in a volume of 100 μl. The EHOMs were then placed on air-liquid culture plates and incubated for 24 hours in 5% CO2 humid atmosphere at 37° C. Following this incubation period, aliquots of the culture supernatant were collected and subjected to a Lactate dehydrogenase (LDH) cytotoxicity assay (Promega, Madison, Wis., USA), as per the manufacturer instructions. 50 μl of each supernatant were transferred to a sterile 96-well flat-bottom plate. Each well was supplemented with 50 μl of reconstituted substrate mix, and the plate was incubated for 30 minutes at room temperature in the dark. To stop the reaction, 50 μl of stop solution was added to each well. Next 100 μl of the mixture was transferred to a 96-well flat-bottom plate, and the absorbance was read at 490 nm with an X-Mark microplate spectrophotometer (Bio-Rad, Mississauga, ON, Canada). LDH was assessed using LDH cytotoxicity assay. Data are means±SD. No significant difference between EHOMs treated with the Example composition and an untreated, uninfected EHOM control was noted.
Wound repair assays were performed. Briefly, oral (gingival) epithelial cells (1×104) and fibroblasts (1×103) were seeded into wells of 6-well plates and grown in appropriate culture medium. Upon confluency, wounds were made in the confluent monolayer of each well using a 200 μL pipette tip. Cultures were then exposed to 1 and 5% by weight dilutions of Examples 3 and 4 for about 2 minutes. Following exposure, the formulations were washed out twice with warm sterile culture medium, and then cell cultures were over layered with DEM for fibroblasts and with DEM for fibroblasts and DMEH for epithelial cells, and cultured for 6 and 24 hours in a 5% CO2 humid atmosphere at 37° C. Wound repair/cell migration was ascertained using optical microscope, and digital photographs were taken (Nikon, Coolpix 950).
The percentage of wound closure (cell growth/migration) was calculated by comparing relative wound areas before and after exposure to the formulations using formula I stated above.
The epithelial cells were small and cuboidal in shape in both treated and untreated cultures. Similar results were observed for scratch wound model using fibroblasts (data not shown). Taken together, this data indicate that example compositions are not toxic and do not negatively impact cell growth/migration and wound healing.
To determine whether glycerine-xanthan gum formulation can form a coating on the human oral mucosa, we spiked the Example 7 formulation with Gentian Violet (GV) as a marker dye. The spiked product (750 μL) was sprayed onto the oral cavity of human volunteers. Post-application, the oral cavity was inspected for staining, and the images were captured using a digital camera. As shown in
To determine the inhibitory activity and duration for which barrier-forming compositions exhibit activity against microbes, time-lapse analysis was performed on cells exposed to the barrier-forming composition, compared to untreated bacteria and fungi.
In Example 162, S. mutans microbial cells were exposed to Example 7 for one minute, washed to remove any residual agent, and allowed to grow in a petri-dish containing fresh growth medium. Growth of organisms at 37° C. was monitored for a 6 hour period, and photomicrographs were taken every 20 minutes over the 6 hour incubation period using a camera connected to the microscope.
In control Example 163 the same procedure was followed with untreated cells.
As shown in
These results further confirmed that the barrier-forming composition possesses prolonged antimicrobial activity.
Short-Term Activity
The duration of activity of Example 7 was determined in healthy individuals by evaluating the effect of a single application on microbial burden of the oral cavity. In Examples 164-166, three healthy individuals (over 18 years of age, healthy mouth) were enrolled with informed consent, and asked to apply a single application of the composition of Example 7 on their cheeks. A single application was defined as three sprays of 0.25 ml each in volume. Next, swabs were collected from these individuals at baseline (pre-treatment), 1 hour, 2 hours, and 6 hours post-treatment. Swabs were cultured on agar media plates specific for aerobic or anaerobic organisms, incubated for 24-28 hours at 37° C., and the number of CFUs were counted. Effect of Example 7 on microbial burden was determined (CFUs), and percentage inhibition was calculated for each post-exposure time point relative to the baseline (0 minutes) CFUs.
The results showed that application of Example 7 led to consistent reduction in microbial load for up to 6 hours (See
The activity of the barrier-forming composition over a 5-day period against oral microbes was evaluated. In Examples 167-169, three healthy individuals were enrolled, and asked to apply a single dosage (three sprays as defined above) of Example 7 three times daily (approximately 9 AM, noon, and 3 PM) for a 5-day period (representing a typical 5-day work-week). Swabs were collected from these individuals at baseline (before application on day 1) and at the end of the day on each day during the 5-day period. Collected swabs were cultured on agar media plates, incubated for 24-28 hours at 37° C. and at 5% CO2 humidity, and the number of CFUs were counted.
The effect of the Example 7 barrier-forming composition on microbial burden was determined (as median CFUs for the three subjects), and percentage inhibition was calculated for each post-exposure time point relative to the baseline (0 min) CFUs.
In a clinical study, twenty-nine healthy individuals were enrolled after informed consent. Baseline information was recorded (age in years, gender, ethnicity, and date of enrolment). Oral examination of the mouth was undertaken, and the inside of the mouth (cheek) was swabbed with a sterile culture swab. Baseline oral swab samples were cultured to determine bacterial load prior to study. In Examples 170-198, each of the twenty-nine participants were given a spray bottle containing the barrier-forming composition of Example 7 and instructed to spray the inside of their mouth six times (total volume sprayed is 0.75 ml), then swish for 30 seconds and swallow. Two groups of participants used the example barrier-forming composition every two hours, three times a day, for five days (a typical work week). Swabs were collected on days 1, 2, 3, and 5 and cultured on media specific for aerobic and anaerobic bacteria. Data were presented as number of microbes: total, aerobic and anaerobic.
Overall, the in vivo testing showed that the barrier-forming composition exhibits antimicrobial activity against oral microbes, as measured by reduction in the levels of these organisms, over both short- and long-term duration.
The data showed that treatment with the barrier-forming composition over a 5-day period resulted in reduction in the oral microbial load, for total microbes, aerobic and anaerobic organisms.
In Example 199 an in vitro filter insert-based model (see
Six compositions were prepared according to Table XII based on the mixing procedures used for Examples 3-8
Next, 100 μL of Examples 199-205 were placed into filter inserts (pore size 0.8 μm diameter, that allows both bacteria and fungi to pass through) and allowed to a form a layer. Next, organisms were overlaid on the layer formed by the test solutions. The filter inserts containing the layer of test solutions and microorganisms were then placed on the surface of agar media plates and incubated for 24 hours at 37° C. After the incubation period, the agar media plates were evaluated for growth on filter insert and in the agar media. Growth on filter insert but no growth in agar media indicated that the test solution formed a barrier, which prevented the microbes from passing through. In contrast, microbial growth in the filter insert as well as the agar media indicated that no such barrier was formed.
The results showed that each of the xanthan gum-based solutions containing the tested humectants (singly or in combination) formed intact barriers on the filter insert that prevented the passage of microorganisms into underlying agar medium.
To determine the solubility of xanthan gum, it was mixed at different concentrations in water and the solubility observed by monitoring the presence or absence of clumps and free flow of the mixture. Table XIII reports the results and concentrations.
We found that when mixed at 0.4%, xanthan gum formed a free-flowing solution (Table XIII). In contrast, mixtures containing 0.45% or 0.5% xanthan gum formed a viscous fluid but contained small clumps. The extent of clumps increased with increasing concentration of xanthan gum (0.6% and 0.7%). At concentrations ≧0.8%, xanthan gum mixture contained extensive clumps, with a jelly-like consistency and no free flow.
In Example 214, the formulation of Example 7 was made, except the neutral agent Citral was used instead of CPC. The antimicrobial activity of formulations containing CPC (0.1%) or Citral (0.5%) against Streptococcus was ascertained. The assay described above in Examples 48-61 was used to perform these studies.
The results showed that the formulation containing citral exhibited antimicrobial activity (MIC=12.5%). However, activity of formulation containing citral was significantly less potent than that containing CPC (MIC=0.098%).
In Example 215 thin layer chromatography analysis was used to compare the hydrophobicity of Example 7 with a hydrophobic composition. The hydrophobic composition was comprised of the components in Table XIV.
10 μL of Example 7 and the hydrophobic composition were deposited on pre-made TLC plates (at a distance of 2 cm from the bottom edge). The spots were air-dried for 5 minutes, and the plates were placed in a TLC chromatography jar containing water as a solvent. The TLC system was allowed to run until the solvent front reached the top edge of the plate. Plates were removed and the solvent and sample fronts were marked. The Relative Front (Rf) values were calculated for the two samples using the formula II:
Rf=Distance travelled by spot/Distance travelled by solvent front II.
The results showed that the Rf value for the hydrophobic composition and Example 7 were 0.33 and 0, respectively, indicating that the hydrophobic composition was highly miscible in water. In contrast, Example 7 did not exhibit any mobility in the aqueous solvent, demonstrating that this formulation is hydrophobic or not hydrophilic.
This application claims the benefit of priority to U.S. provisional application No. 61/477,147, filed on Apr. 19, 2011, entitled “Compositions, Methods of Use, and Methods of Making Barrier Products.” That provisional application is incorporated herein by reference for all purposes.
| Number | Date | Country | |
|---|---|---|---|
| 61477147 | Apr 2011 | US |
