VIRUS INACTIVATING AGENT

Abstract

The purpose of the present invention is to provide: a virus inactivating agent that exhibits an effect at an amount that does not cause skin irritation; and an external skin preparation composition containing said virus inactivating agent. The present invention relates to: a virus inactivating agent containing, as an effective component thereof, at least one selected from mint oil, eucalyptus oil, rosemary oil, sage oil, tea tree oil, shell ginger oil, peppermint oil, lemongrass oil, cajeputi oil, niaouli cineole oil, lime oil, lemon oil, lemon verbena oil, St. John's wort oil, ravintsara oil, rosewood oil, Melissa/lemon balm oil, myrrh oil, mandarin oil, vetiver oil, frankincense oil, citronella oil, cardamom oil, Angelica oil, and cationized starch; and an external skin preparation composition containing the same.

Claims

1. A method for inactivating a virus, comprising: applying a virus inactivating agent to viruses, wherein: said virus inactivating agent comprises 0.1% by mass or more of a cationic starch.

2. The method according to claim 1, wherein the cationic starch is a cationic polymer represented by the following formula (I): ##STR00003## wherein X— represents an anion derived from an inorganic acid or an organic acid; a is 0.6 to 0.9 and b is 0.4 to 0.1, provided that a and b satisfy 2+b=1; and an average molecular weight is 30,000 to 1,000,000.

3. The method according to claim 2, wherein an average molecular weight of the cationic starch is 100,000 to 500,000.

4. The method according to claim 1, wherein the cationic starch is starch hydroxypropyltrimonium chloride.

Description

DESCRIPTION OF EMBODIMENTS

[0020] Hereinafter, the present invention will be described further in detail.

[0021] One aspect is that the virus inactivating agent of the present invention comprises, as active ingredient, one or two or more plant extracts, wherein the plant extract derives from a plant, selected from the group consisting of mint (family Lamiaceae, genus Mentha), eucalyptus (family Myrtaceae, genus Eucalyptus), rosemary (family Lamiaceae, genus Rosmarinus), sage (family Lamiaceae, genus Salvia), tea tree (family Myrtaceae, genus Melaleuca), getto (family Zingiberaceae, genus Alpinia), peppermint (family Lamiaceae, genus Mentha), lemongrass (family Poaceae, genus Cymbopogon), cajeput (family Myrtaceae, genus Melaleuca), niaouli cineole (family Myrtaceae, genus Melaleuca), lime (family Rutaceae, genus Citrus), lemon (family Rutaceae, genus Citrus), lemon verbena (family Verbenaceae, genus Aloysia), St. John's wort (family Guttiferae, genus Hypericum), ravintsara (family Lauraceae, genus Cinnamomum), rosewood (family Fabaceae, genus Dalbergia), melissa/lemonbalm (family Lamiaceae, genus Melissa), myrrh (family Burseraceae, genus Commiphora), mandarin (family Rutaceae, genus Citrus), vetiver (family Poaceae, genus Chrysopogon), frankincense (family Burseraceae, genus Boswellia), citronella (family Poaceae, genus Cymbopogon), cardamon (family Zingiberaceae, genus Elettaria), and angelica (family Apiaceae, genus Angelica).

[0022] As the plant extract in the present invention, an “essential oil” extracted as an aromatic substance contained in the above-mentioned plants is preferable.

[0023] The essential oil in a narrow sense obtained by steam distillation from the above plants or dried materials thereof is preferably used as the “essential oil” in the present invention, but is not limited thereto. For example, oils extracted from the plants by using other methods such as extraction or expression are also included in the “essential oil” of the present invention as long as they contain essential oil components (such as aromatic substances).

[0024] As other methods for extracting essential oils from plants, for example, solvent extraction (such as alcohol extraction, organic solvent extraction), oil and fat adsorption extraction (hot enfleurage or cold enfleurage), and supercritical fluid extraction are known. When the steam distillation cannot be applied because of a low essential oil content in the plant and the like, the solvent extraction is often used. Examples of the solvent used for extraction include, but are not limited to, alcohols such as ethanol, methanol, propanol, isopropanol, and butanol, and organic solvents including relatively high polarity solvents such as acetone and low polarity solvents such as hexane. Regarding the details of these methods for extracting essential oils, reference can be made to publications such as “Patent Office Report: Collection of Well-Known Prior Arts (flavors and fragrances), Part 1, General fragrance” (Jan. 29, 1999, published by the Japan Patent Office, pp. 4-21 (2.1.1 plant fragrances)).

[0025] The “essential oil” in the present invention may be those in which the oil obtained by the above method is further purified and concentrated by using various purification procedures such as hydrophobic or adsorptive chromatography using a support such as porous beads, silica gel, or alumina.

[0026] As used herein, each “essential oil” obtained from each plant listed in paragraph 0015 refers to mint oil, eucalyptus oil, rosemary oil, sage oil, tea tree oil, getto oil, peppermint oil, lemongrass oil, cajeput oil, niaouli cineole oil, lime oil, lemon oil, lemon verbena oil, St. John's wort oil, ravintsara oil, rosewood oil, melissa/lemon balm oil, myrrh oil, mandarin oil, vetiver oil, frankincense oil, citronella oil, cardamon oil, and angelica oil.

[0027] The virus inactivating agent of the present invention comprises, as active ingredient, one or two or more essential oils selected from the group consisting of mint oil, eucalyptus oil, rosemary oil, sage oil, tea tree oil, getto oil, peppermint oil, lemongrass oil, cajeput oil, niaouli cineole oil, lime oil, lemon oil, lemon verbena oil, St. John's wort oil, ravintsara oil, rosewood oil, melissa/lemon balm oil, myrrh oil, mandarin oil, vetiver oil, frankincense oil, citronella oil, cardamon oil, and angelica oil. It is preferable to comprise preferably two, more preferably three, and further preferably four or more essential oils.

[0028] Among the above-mentioned essential oils, it is preferable to select the essential oil in which the content of limonene is 10 g or less, preferably 8 g or less, and more preferably 6 g or less per 100 g of the essential oil. In particular, it is preferable to use at least one selected from the group consisting of mint oil, eucalyptus oil, rosemary oil, and sage oil. A preferred aspect of the virus inactivating agent of the present invention comprises, as active ingredient, two, preferably three, and more preferably four selected from the group consisting of mint oil, eucalyptus oil, rosemary oil, and sage oil.

[0029] The virus inactivating agent of the present invention preferably contain essential oils in combination so that the content of limonene contained in the essential oils is 0.006% by mass or more based on the total amount of the virus inactivating agent. If the content of limonene is less than 0.006% by mass, a sufficient virus inactivation effect cannot be obtained.

[0030] Limonene is a monocyclic monoterpene hydrocarbon mainly contained in fruit peels of citrus fruits. Limonene is a main component of the essential oils obtained from citrus fruits such as oranges and lemons, and it is known that the limonene contained in orange peel oil and lemon oil is D-form and the limonene contained in mint oil and the like is L-form. The limonene used in the present invention may be D-form, L-form, or a mixture of D-form and L-form (racemate, etc.) and is not particularly limited. More specifically, the virus inactivating agent of the present invention includes an aspect of containing 0.006% by mass or more of D-limonene, an aspect of containing 0.006% by mass or more of L-limonene, and an aspect of containing D-limonene and L-limonene in a total amount of 0.006% by mass or more.

[0031] The upper limit of the content of limonene is not particularly limited, but is typically 0.05% by mass or less, preferably 0.04% by mass or less, 0.03% by mass or less, or 0.02% by mass or less. Too high a content of limonene may cause skin irritation.

[0032] The amount of limonene based on the total amount of essential oil to be included is less than 5 g, preferably less than 4.5 g per 100 g of the essential oil.

[0033] Another aspect of the virus inactivating agent of the present invention comprises cationic starch as an active ingredient.

[0034] The cationic starch is a cationic polymer obtained by introducing a cationic group such as quaternary ammonium salt into a starch having a structure in which a plurality of glucose is linked via α-1,4-glucoside bonds as the basic skeleton.

[0035] Preferred examples of the cationic starch used in the present invention include the cationic polymer represented by the following formula (I):

##STR00002##

[0036] Each symbol in the above formula (I) represents the following meanings.

[0037] X— indicates an anion derived from an inorganic acid or an organic acid. Examples of the inorganic acid include hydrochloric acid, sulfuric acid, and nitric acid, and examples of the organic acid include carboxylic acids such as acetic acid. As for the anion X— in the above formula (I), halide ions, in particular, Cl— are preferred.

[0038] a and b represent each number of monomers and the ratio of each monomer in the polymer. In representing each number of monomers, the average molecular weight of the cationic starch represented by Formula (I) (the weight average molecular weight: Mw) is preferably 30,000 to 1,000,000 and more preferably 100,000 to 500,000, and therefore, a and b take values such that the average molecular weight can be within the above-mentioned range. In representing the ratio of each monomer, for example, a is 0.6 to 0.9, preferably 0.7 to 0.8, and more preferably about 0.75, and b is 0.4 to 0.1, preferably 0.3 to 0.2, and more preferably about 0.25, provided that a+b=1.

[0039] The cationic starch represented by Formula (I) is “starch hydroxypropyltrimonium chloride” in a cosmetic labeling name. Examples of the products commercially available under this labeling name include “Sensomer CI-50” (manufactured by NALCO Performance Products), “DOCCTARCH CP” (manufactured by DOC Japan), “amylomer 25L” (manufactured by Graefe Chemie), “amylomer 50M” (manufactured by Graefe Chemie), “FARMAL MS5940” (manufactured by Corn Products International), and “EXCEL FM-004” (manufactured by NIPPON STARCH CHEMICAL CO., LTD.), and these commercial products can be used. Among these, “Sensomer CI-50” (average molecular weight=200,000; a:b=0.75:0.25) can be preferably used.

[0040] Although the cationic starch is mainly used as a hair conditioning agent as a cationic polymer along with cationic cellulose, polyquaternium, and the like, the fact that cationic starch has the virus inactivation effect is a surprising finding that has been found out for the first time by the present invention.

[0041] In the virus inactivating agent of the present invention, the content of the cationic starch is 0.1% by mass or more, preferably 0.15% by mass or more, and more preferably 0.2% by mass or more in terms of the pure polymer based on the total amount of the virus inactivating agent. If the content is less than 0.1% by mass, a sufficient virus inactivation effect cannot be obtained. The upper limit of the content of the cationic starch is not particularly limited, but typically 5% by mass or less, preferably 3% by mass or less, and more preferably 2% by mass or less.

[0042] In the present invention and the specification of the present application, “virus inactivation” refers to removing or significantly reducing the infectivity or the growth capacity of the virus. The virus that can be inactivated by the virus inactivating agent of the present invention is not particularly limited and various viruses can be inactivating targets regardless of the genome type or the presence or absence of an envelope.

[0043] Examples of the inactivating target include influenza virus types A, B, and C, isavirus, quaranjavirus, thogotovirus, rhinovirus, poliovirus, rotavirus, norovirus, enterovirus, hepatovirus, astrovirus, sapovirus, hepatitis E virus, parainfluenza virus, mumps virus, measles virus, human metapneumovirus, RS virus, Nipah virus, hendra virus, yellow fever virus, dengue virus, Japanese encephalitis virus, West Nile virus, hepatitis B and C viruses, Eastern and Western equine encephalitis viruses, rubella virus, Lassa virus, Junin virus, Machupo virus, Guanarito virus, Sabia virus, Crimean-Congo hemorrhagic fever virus, hantavirus, Sin Nombre virus, rabies virus, Ebola virus, Marburg virus, bat Lyssavirus, human T cell leukemia virus, human immunodeficiency virus, human coronavirus, SARS coronavirus, human parvovirus, polyomavirus, human papilloma virus, adenovirus, herpes virus, varicella zoster virus, EB virus, cytomegalovirus, smallpox virus, monkeypox virus, cowpox virus, molluscipoxvirus, and parapoxvirus; and the inactivating target is preferably enveloped single-stranded RNA viruses, more preferably influenza virus types A, B, and C, Isavirus, Quaranjavirus, and Thogotovirus that belong to family Orthomyxoviridae, and particularly preferably influenza virus.

[0044] Although the virus inactivating agent of the present invention exerts a sufficient effect by individually containing one or two or more essential oils selected from the group consisting of mint oil, eucalyptus oil, rosemary oil, sage oil, tea tree oil, getto oil, peppermint oil, lemongrass oil, cajeput oil, niaouli cineole oil, lime oil, lemon oil, lemon verbena oil, St. John's wort oil, ravintsara oil, rosewood oil, melissa/lemon balm oil, myrrh oil, mandarin oil, vetiver oil, frankincense oil, citronella oil, cardamon oil, and angelica oil, or cationic starch, the virus inactivating agent may comprise the essential oil and the cationic starch in combination as active ingredient.

[0045] The present invention provides a skin external-preparation composition comprising the above virus inactivating agent. The “skin external-preparation composition” of the present invention may be an external-preparation composition applied to the skin (including the scalp), and examples thereof include a cosmetic (including a base cosmetic and a makeup cosmetic), a cleanser, an external medicine, and an external quasi drug.

[0046] The skin external-preparation composition of the present invention may be in the form consisting of only the above-described virus inactivating agent, or in the form in which various components typically used in skin external-preparation compositions are appropriately contained as needed.

[0047] For example, the skin external-preparation composition of the present invention may comprise a lower alcohol (an alcohol having 6 carbon atoms or less) such as ethanol. It is known that a lower alcohol such as ethanol has inactivation effects on various viruses including influenza virus, and a virus inactivating agent composition with a high content of an alcohol is also known. However, in the skin external-preparation composition of the present invention, it is preferable that the content of an alcohol, if it is contained, be 50% by mass or less, preferably 40% by mass or less or 30% by mass or less, whereby people having sensitive skin can use it without anxiety.

[0048] Examples of other optional components that can be contained in the skin external-preparation composition of the present invention include an oil (such as animal and vegetable oils, mineral oil, ester oil, wax oil, silicone oil, higher alcohol, phospholipid, and fatty acid), a surfactant (anionic, cationic, amphoteric or nonionic surfactants), a vitamin (such as vitamin A group, vitamin B group, folate, nicotinic acid, pantothenic acid, biotin, vitamin C group, vitamin D group, vitamin E group, other ferulic acid, and γ-oryzanol), an ultraviolet absorber (such as p-aminobenzoic acid, anthranil, salicylic acid, coumalin, benzotriazole, tetrazole, imidazoline, pyrimidine, dioxane, furan, pyrone, camphor, nucleic acid, allantoin and their derivatives, amino acid-based compounds, shikonin, baicalin, baicalein, and berberine), an antioxidant (such as stearic acid ester, nordihydroguaiaretic acid, dibutylhydroxytoluene, butylhydroxyanisole, parahydroxyanisole, propyl gallate, sesamol, sesamolin, and gossypol), a thickener (hydroxyethyl cellulose, ethyl cellulose, carboxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, sodium carboxymethyl cellulose, hydroxypropyl cellulose, nitrocellulose, polyvinyl alcohol, polyvinyl methyl ether, polyvinyl pyrrolidone, polyvinylmethacrylate, polyacrylate, carboxyvinyl polymer, gum arabic, tragacanth gum, agar, casein, dextrin, gelatin, pectine, and alginic acid and a salt thereof), a moisturizing agent (such as propylene glycol, 1,3-butylene glycol, polyethylene glycol, glycerin, 1,2-pentanediol, hexylene glycol, chondroitin sulfate and a salt thereof, hyaluronic acid and a salt thereof, and sodium lactate), a water-soluble polymer, a pH adjuster, an antiseptic/antifungal agent, a coloring agent, a cooling agent, a stabilizing agent, a microbial culture metabolic component, a blood flow enhancer, an antiphlogistic agent, an anti-inflammatory agent, an anti-allergic agent, amino acid and a salt thereof, a keratolytic agent, an astringent, a wound healing agent, a deodorant, and various powder components. One of these components may be selected and added, or two or more thereof may be used in combination.

[0049] The dosage form of the skin external-preparation composition of the present invention may be any form and for example, may be in the form of a skin lotion, a cream, a salve, an emulsion, a foundation, an oil, a mask, a soap (including a medicated soap), a body soap, a lipstick, a fragrance, a facial wash, a deodorizer (such as underarm odor and foot odor), a bath agent, a shampoo, a conditioner, a hair tonic, and a hair spray.

[0050] The form of the skin external-preparation composition of the present invention may be a solution, a cream, a paste, a gel, a foam, a solid, or a powder, depending on the dosage form thereof.

[0051] The skin external-preparation composition of the present invention can be prepared in accordance with a usual method depending on the dosage form and the form, by comprising the virus inactivating agent mentioned above as an essential component.

EXAMPLES

[0052] Hereinafter, the present invention will be described further in detail with reference to Examples, but the present invention is not limited by these Examples. The “%” in Examples refers to “% by mass” unless otherwise specified.

Example 1

Inactivation Effect on Influenza Virus (No. 1)

[0053] 1) Preparation of Samples (Test Solutions)

[0054] Samples (test solutions) of virus inactivating agents were prepared by the formulations shown in Table 1 below.

TABLE-US-00001 TABLE 1 Sample Sample Sample Sample Sample Sample Sample Sample 1 2 3 4 5 6 7 8 Water Balance Balance Balance Balance Balance Balance Balance Balance Citric acid 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 (food products) Sodium citrate 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 PEG-60 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 hydrogenated castor oil 1,3-BG 5 5 5 5 5 5 5 5 Mint oil — 0.07 0.0233 0.007 0.03 — — — Rosemary oil — 0.032 0.0107 0.0032 — 0.03 — — Eucalyptus oil — 0.03 0.01 0.003 — — 0.03 — Sage oil — 0.02 0.0067 0.002 — — — 0.03 Total 100 100 100 100 100 100 100 100 Amount of — 0.0065 0.0022 0.0007 0.0013 0.0008 0.0016 0.0015 limonene

[0055] 2) Test Method

[0056] Influenza virus type A (H1N1/PR/8/34) strain was used as a test strain.

[0057] To 1.080 mL of each sample (test solution) shown in Table 1, 0.12 mL (1×10.sup.4 pfu/mL) of the viral solution was added, and after reaction for 30 minutes, the solution was serially diluted 10-fold in SCDLP media and inoculated on canine kidney cells (MDCK) which were cultured in 96 well plates in advance. After culture under the conditions of 37° C. and 5% CO.sub.2, the number of plaques formed was measured to determine the residual virus infectious titer.

[0058] 3) Test Results

[0059] The results are shown in Table 2. As shown in Table 2 below, in the combination of four mint-based essential oils (mint oil, rosemary oil, eucalyptus oil, and sage oil) (Sample 2), the logarithmic reduction value of the virus infectious titer was about 4 and it was shown to have a high inactivation effect on the influenza virus. On the contrary, in other samples (3 to 8) in which the amount of limonene was less than 0.006% by mass by reducing the number of essential oils or by reducing the amount of essential oils to be added, no virus inactivation effect was observed in any case.

TABLE-US-00002 TABLE 2 Virus infectious titer Virus Logarithmic reduction value inactivation Sample 1 0.459 Poor Sample 2 3.868 Good Sample 3 1.086 Poor Sample 4 0.818 Poor Sample 5 0.981 Poor Sample 6 0.937 Poor Sample 7 0.905 Poor Sample 8 0.823 Poor

Example 2

[0060] Inactivation Effect on Influenza Virus (No. 2)

[0061] 1) Preparation of Samples (Test Solutions)

[0062] Samples (test solutions) of virus inactivating agents were prepared by the formulation shown in Table 3 below.

TABLE-US-00003 TABLE 3 Sample 9 Sample 10 Sample 11 Sample 12 Water Balance Balance Balance Balance Citric acid (food 0.02 0.02 0.02 0.02 products) Sodium citrate Na 0.08 0.08 0.08 0.08 PEG-60 hydrogenated 0.1 0.1 0.1 0.1 castor oil 1,3-Butylene glycol 5 5 5 5 Cationic starch (*1) — 0.24 0.024 — Cationic cellulose (*2) — — — 0.1 Total 100 100 100 100 (*1) Sensomer IC-50 (*2) Polymer JR-400 (manufactured by Union Carbide Corporation)

[0063] 2) Test Method

[0064] The test method was in accordance with the test method described in the above Example 1.

[0065] 3) Test Results

[0066] The results are shown in Table 4. As shown in Table 4 below, in Sample 10 which contains 0.24% by mass of cationic starch (starch hydroxypropyltrimonium chloride) in terms of the pure polymer, the logarithmic reduction value of the virus infectious titer was 4 or more, and it was shown to have a significantly high influenza virus inactivation effect. On the contrary, no virus inactivation effect was observed in Sample 12 in which a similar amount (0.1% by mass) of a cationic cellulose derivative (hydroxyethylcellulose hydroxypropyltrimonium chloride) was contained in terms of the pure polymer, and in Sample 11 in which the content of the cationic starch was less than its effective amount (0.024% by mass).

TABLE-US-00004 TABLE 4 Virus infectious titer Virus Logarithmic reduction value inactivation Sample 9 0.459 Poor Sample 10 4.345 Good Sample 11 0.550 Poor Sample 12 0.720 Poor

[0067] Hereinafter, other formulation examples of the skin external-preparation composition according to the present invention will be listed.

TABLE-US-00005 (Formulation Example 1) Skin external- preparation (virus block mist) Components included % by mass Ethanol 20.0 Cationic starch(*) 1.0 Citric acid 0.02 Sodium citrate 0.08 Water balance Total 100 (*)Sensomer CI-50

[0068] An antivirus mist was obtained by discharging the skin external-preparation of the above-mentioned Formulation Example 1 by a mist dispenser.

[0069] Moreover, an aerosol product may be produced by using this formulation as a stock solution and by appropriately using a compressed gas (such as nitrogen, LPG, and carbonic acid).

TABLE-US-00006 (Formulation Example 2) Skin external-preparation (gel) Components included % by mass Ethanol 30.0 Mint oil 0.07 Rosemary oil 0.032 Sage oil 0.02 Eucalyptus oil 0.03 (PEG-240/Decyltetradeceth-20/HDI) Copolymer 0.5 Carboxyvinyl polymer 0.45 2-Amino-2-methyl-1,3-propanediol 0.4 (Acrylates/Alkyl Acrylate (C10-30)) Crosspolymer 0.05 Polyquaternium-51 0.1 Water balance Fragrance 0.1 Total 100

TABLE-US-00007 (Formulation Example 3) Skin external-preparation (gel) Components included % by mass Hydroxypropylcellulose 0.5 Cationic starch (*) 1.0 Water balance Total 100 (*) Sensomer CI-50

TABLE-US-00008 (Formulation Example 4) Skin external-preparation (gel) Components included % by mass Ethanol 10.0 Mint oil 0.07 Rosemary oil 0.032 Sage oil 0.02 Eucalyptus oil 0.03 Carboxyvinyl polymer 0.5 Potassium hydrate 0.2 Glycerin 10.0 PEG-60 Hydrogenated Castor Oil 0.1 Water balance Total 100