Virus inactivation agents

Abstract

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 the virus inactivating agent.SOLUTION: A virus inactivating agent includes at least 0.1 mass% of a cationized starch represented by the formula (I), and an external skin preparation composition containing the virus inactivating agent.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a virus inactivating agent containing as an active ingredient one or more selected from specific essential oils, namely mint oil, eucalyptus oil, rosemary oil, sage oil, tea tree oil, shell ginger oil, peppermint oil, lemongrass oil, cajeput oil, niaouli-cineole oil, lime oil, lemon oil, lemon verbena oil, St. John's wort oil, lavandula angustifolia oil, rosewood oil, melissa / lemon balm oil, myrrh oil, mandarin oil, vetiver oil, frankincense oil, citronella oil, cardamom oil and angelica oil, and cationic starch, and a skin external preparation composition containing the virus inactivating agent. [Background technology]

[0002] It is known that plant extracts, particularly some essential oils extracted from aromatic substances contained in plant extracts, have an inactivating effect on various viruses including influenza viruses. "Essential oils" are a type of natural fragrance in cosmetics, and in the narrow sense, are oils obtained by steam distillation from plants or their dried products. Known methods for extracting natural fragrances include extraction and pressing, and fragrances obtained by pressing are sometimes called essential oils (Non-Patent Document 1).

[0003] For example, raspberry (Rubus idaeus), strawberry (Fragaria vesca), blackberry (Rubus fruticosus), fig (Ficus carica), pigweed (Chenopodium album), agrimony (Agrimonia eupatoria), eucalyptus (Eucalyptus globulus), peach (Prunus persica), apple (Malus pumila), violet (Viola odorata), Japanese spicebush (Lindera umbellata), guarana (Paullinia cupana), cotton deutzia (Buddleia officinalis), dayflower (Commelina communis), shepherd's purse (Capsella bursapastoris), emmeiso (Rabdosia japonica), wild strawberry (Fragaria v esca), horehound (Marrubium vulgare), marshmallow (Althaea Patent Document 1 describes that one or more plant extracts selected from the group consisting of Prunus officinalis, Plantago asiatica, Lemon verbena (Aloysia triphylla), Yarrow (Achillea millefolium), Iceland moss (Cetraria islandica), Gynostemma pentaphyllum (Hydrangea serrata), and Butterbur (Petasites japonicus) exhibit influenza virus inactivation effects. However, the plant extract used in Patent Document 1 is obtained by an extraction method using water / ethanol (or an organic solvent), and is intended to be added to food and orally administered.

[0004] Patent Document 2 describes that an essential oil component obtained by steam distillation of Houttuynia cordata Thunbo exhibits an inactivating effect against influenza virus, herpes simplex virus type 1 (HSV-1), AIDS virus (HIV), etc., and Patent Document 3 describes that an essential oil extract of patchouli (Pogostemon cablin Benth.) has an influenza virus inactivating effect. However, the active ingredients specified in Patent Document 2 are non-terpene compounds contained in the essential oil component, namely n-decyl aldehyde, n-dodecyl aldehyde, and methyl n-nonyl ketone, while the active ingredient in Patent Document 3 is patchouli alcohol (patchoul) obtained by extracting patchouli with alcohol or n-hexane and then fractionating it.

[0005] Patent Document 4 discloses that fir leaf extract (fir essential oil) is useful as an anti-influenza virus agent, and that the essential oil preferably contains 30% by mass or more of bornyl acetate, and the total amount of camphene, pinene, and limonene added thereto is preferably 90% by mass or more based on the total amount of fir essential oil. Patent Document 5 reports that terpene derivatives such as pinenes, phenols such as eugenol, and sandalwood oil exhibit an inactivating effect against pathogenic membrane-bound viruses such as the measles virus.

[0006] However, when it comes to essential oils, from the standpoint of safety (skin irritation), it is not realistic to contain them in an amount effective for inactivating viruses, and therefore there has been a strong desire to develop a virus inactivating agent that contains safe natural ingredients that are effective in smaller amounts.

[0007] On the other hand, although it is not a natural component, it has been reported that a quaternary ammonium cation containing silicon, such as dimethyloctadecyl[3-(triethoxysilyl)propyl]ammonium chloride (EtAC), is safe for use as an oral cleaning agent such as a denture cleaner, and has the ability to inactivate viruses such as influenza virus and norovirus (Patent Document 6). However, Patent Document 6 suggests that even slight differences in the structure of the quaternary ammonium cation can cause problems in the antiviral effect and stability (paragraphs 0008 and 0009). [Prior art documents] [Non-patent literature]

[0008] [Non-Patent Document 1] "New Cosmetics Science", 2nd edition, edited by Takeo Mitsui, Nanzando, 2001, p. 119 [Patent documents]

[0009] [Patent Document 1] JP 2004-59463 A [Patent Document 2] Japanese Patent Application Publication No. 7-118160 [Patent Document 3] JP 2011-79800 A [Patent Document 4] JP 2011-84503 A [Patent Document 5] Japanese Patent Application Publication No. 5-306217 [Patent Document 6] JP 2011-98976 A Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention was made in consideration of the above-mentioned technical situation and the current situation in which there is an increase in irritants that can adversely affect the skin, including not only bacteria and viruses but also air pollutants such as pollen and PM2.5, and an object of the present invention is to provide a virus inactivating agent that is effective in an amount that does not cause skin irritation, and a skin topical preparation composition containing the virus inactivating agent. [Means for solving the problem]

[0011] As a result of intensive research aimed at solving the above problems, the inventors have discovered that by incorporating one or more essential oils extracted from specific plants and / or cationic starch as active ingredients, excellent virus inactivation effects can be achieved safely without causing skin irritation, and have thus completed the present invention.

[0012] That is, the present invention includes the following. [1] A virus inactivating agent characterized by containing as an active ingredient one or more selected from peppermint oil, eucalyptus oil, rosemary oil, sage oil, tea tree oil, shell ginger oil, peppermint oil, lemongrass oil, cajeput oil, niaouli-cineole oil, lime oil, lemon oil, lemon verbena oil, St. John's wort oil, lavandula angustifolia oil, rosewood oil, melissa / lemon balm oil, myrrh oil, mandarin oil, vetiver oil, frankincense oil, citronella oil, cardamom oil, angelica oil, and cationic starch. [2] The virus inactivating agent according to [1] above, characterized in that it contains, as an active ingredient, one or more oils selected from the group consisting of peppermint oil, eucalyptus oil, rosemary oil, and sage oil. [3] The virus inactivating agent according to [2] above, characterized in that it contains, as active ingredients, three oils selected from the group consisting of peppermint oil, eucalyptus oil, rosemary oil, and sage oil. [4] The virus inactivating agent according to [2] above, characterized in that it contains peppermint oil, eucalyptus oil, rosemary oil, and sage oil as active ingredients. [5] The virus inactivating agent according to any one of [1] to [4] above, having a total limonene content of 0.006% by mass or more. [6] The virus inactivating agent according to the above item [1], characterized in that it contains cationic starch as an active ingredient. [7] The cationic starch has the following formula (I): [ka] [In formula (I), X- represents an anion derived from an inorganic acid or an organic acid; a and b are, when a+b=1, a is 0.6 to 0.9, and b is 0.4 to 0.1; The average molecular weight is 30,000 to 1,000,000. The virus inactivating agent according to the above-mentioned [1] or [6], which is a cationic polymer represented by the following formula: [8] The virus inactivating agent according to any one of the above [1], [6] and [7], wherein the average molecular weight of the cationic starch is 100,000 to 500,000. [9] The virus inactivating agent according to any one of [1] and [6] to [8] above, wherein the cationic starch is hydroxypropyltrimonium starch chloride.

[10] The virus inactivating agent according to any one of [1] and [6] to [9] above, wherein the amount of cationic starch blended is 0.1 mass% or more calculated as the pure content of hydroxypropyltrimonium starch chloride.

[11] The virus inactivating agent according to any one of [1] to

[10] above, wherein the virus is an enveloped single-stranded RNA virus.

[12] The virus inactivating agent according to

[11] above, wherein the enveloped single-stranded RNA virus is a virus belonging to the Orthomyxoviridae family.

[13] The virus inactivating agent according to

[12] above, wherein the virus belonging to the Orthomyxoviridae family is an influenza virus.

[14] A skin external preparation composition comprising the virus inactivating agent according to any one of [1] to

[13] above.

[15] The skin topical composition according to

[14] above, further comprising alcohol.

[16] The skin topical composition according to

[15] above, wherein the amount of alcohol contained is 50% by mass or less. Effect of the Invention

[0013] In one embodiment of the virus inactivating agent of the present invention, preferably by combining multiple essential oils with low limonene content to make the total amount of limonene equal to or greater than a predetermined amount, the virus inactivating agent of the present invention exhibits excellent virus inactivating effect without causing skin irritation. In addition, the virus inactivating agent of the present invention exhibits excellent virus inactivating effect by blending a naturally derived component, cationic starch. Therefore, the skin external preparation composition containing the virus inactivating agent of the present invention has the advantage of having a virus inactivating effect safely and easily. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The present invention will now be described in further detail.

[0015] One embodiment of the virus inactivating agent of the present invention comprises one or more kinds of plant extracts as an active ingredient, and the plant extracts are selected from the group consisting of mint (genus Mentha, Lamiaceae), eucalyptus (genus Eucalyptus, Myrtaceae), rosemary (genus Rosemary, Lamiaceae), sage (genus Salviae, Lamiaceae), tea tree (genus Melange, Myrtaceae), shell ginger (genus Alpinia, Zingiberaceae), peppermint (genus Mentha, Lamiaceae), lemongrass (genus Cymbidium, Poaceae), cajeput (genus Melange, Myrtaceae), niaouli cineole (genus Melaleuca, Myrtaceae), lime (genus Citrus, Rutaceae), lemon (genus Citrus, Rutaceae), and vervain. The composition is characterized in that it is derived from a plant selected from the group consisting of lemon verbena (genus Celastrus, family Hypolimnaea), St. John's wort (genus Hypericum, family Hypericaceae), lavandula angustifolia (genus Cinnamomum, family Lauraceae), rosewood (genus Dalasia, family Fabaceae), melissa / lemon balm (genus Mentha, family Lamiaceae), myrrh (genus Commiphora, family Burseraceae), mandarin (genus Citrus, family Rutaceae), vetiver (genus Atractylodes spp., family Poaceae), frankincense (genus Boswellia, family Burseraceae), citronella (genus Cymbidium, family Poaceae), cardamom (genus Euonymus, family Zingiberaceae), and angelica (genus Angelica, family Apiaceae).

[0016] The plant extract in the present invention is preferably an "essential oil" extracted as an aromatic substance contained in the above-mentioned plant. The "essential oil" in the present invention is preferably an essential oil in the narrow sense obtained by steam distillation from the above-mentioned plants or their dried products, but is not limited thereto. For example, oils extracted from plants by other methods such as extraction and pressing are also included in the "essential oil" in the present invention as long as they contain essential oil components (fragrant substances, etc.).

[0017] Other methods for extracting essential oils from plants include, for example, solvent extraction (alcohol extraction, organic solvent extraction, etc.), fat and oil adsorption extraction (hot or cold infusion), and supercritical fluid extraction. Solvent extraction is often used when steam distillation cannot be applied due to the low essential oil content of the plant. Examples of solvents used for extraction include, but are not limited to, alcohols such as ethanol, methanol, propanol, isopropanol, and butanol, and organic solvents ranging from relatively high polarity such as acetone to low polarity such as hexane. For details of these essential oil extraction methods, reference can be made to literature such as "Patent Office Public Relations: Collection of Well-Known and Commonly Used Technologies (Fragrances) Part I: General Fragrances" (published by the Japan Patent Office on January 29, 1999, pp. 4-21 (2·1·1 Vegetable Fragrances)).

[0018] The "essential oil" in the present invention may be an oil obtained by the above-mentioned method, which is further purified and concentrated using various purification techniques, such as hydrophobic or adsorption chromatography using carriers such as porous beads, silica gel, or alumina.

[0019] In this specification, the "essential oils" obtained from each of the plants listed in paragraph 0015 are referred to as peppermint oil, eucalyptus oil, rosemary oil, sage oil, tea tree oil, alpinia ginseng oil, peppermint oil, lemongrass oil, cajeput oil, niaouli-cineole oil, lime oil, lemon oil, lemon verbena oil, St. John's wort oil, lavandula angustifolia oil, rosewood oil, melissa / lemon balm oil, myrrh oil, mandarin oil, vetiver oil, frankincense oil, citronella oil, cardamom oil, and angelica oil, respectively.

[0020] The virus inactivating agent of the present invention contains one or more essential oils selected from the group consisting of peppermint oil, eucalyptus oil, rosemary oil, sage oil, tea tree oil, shell ginger oil, peppermint oil, lemongrass oil, cajeput oil, niaouli-cineole oil, lime oil, lemon oil, lemon verbena oil, St. John's wort oil, lavandula angustifolia oil, rosewood oil, melissa / lemon balm oil, myrrh oil, mandarin oil, vetiver oil, frankincense oil, citronella oil, cardamom oil, and angelica oil as an active ingredient. It is preferable to contain two kinds, more preferably three kinds, and even more preferably four or more kinds of essential oils.

[0021] Among the above essential oils, it is preferable to select an essential oil having a limonene content of 10g or less, preferably 8g or less, more preferably 6g or less per 100g of essential oil. In particular, it is preferable to use at least one oil selected from the group consisting of peppermint oil, eucalyptus oil, rosemary oil, and sage oil. A preferred embodiment of the virus inactivating agent of the present invention contains two, preferably three, more preferably four oils selected from the group consisting of peppermint oil, eucalyptus oil, rosemary oil, and sage oil as active ingredients.

[0022] In addition, the virus inactivating agent of the present invention is preferably formulated in such a manner that the content of limonene contained in the essential oils to be formulated is 0.006% by mass or more relative to the total amount of the virus inactivating agent. If the amount of limonene blended is less than 0.006% by mass, a sufficient virus inactivating effect cannot be obtained.

[0023] Limonene is a monocyclic monoterpene hydrocarbon mainly contained in the peels of citrus fruits. Limonene is the main component of essential oils obtained from citrus fruits such as oranges and lemons, but it is known that the limonene contained in orange peel oil and lemon oil is the D-isomer, and the limonene contained in peppermint oil and the like is the L-isomer. The limonene used in the present invention may be the D-isomer, the L-isomer, or a mixture of the D-isomer and the L-isomer (racemic or the like), and is not particularly limited. That is, the virus inactivating agent of the present invention includes an embodiment containing 0.006% by mass or more of D-limonene, an embodiment containing 0.006% by mass or more of L-limonene, and an embodiment containing 0.006% by mass or more of D-limonene and L-limonene in total.

[0024] The upper limit of the amount of limonene to be blended is not particularly limited, but is usually 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. If the amount of limonene to be blended is too high, it may cause skin irritation. The amount of limonene relative to the total amount of essential oils to be blended is preferably less than 5 g, more preferably less than 4.5 g, per 100 g of essential oil.

[0025] Another embodiment of the virus inactivating agent of the present invention contains cationic starch as an active ingredient. Cationic starch is a cationic polymer in which cationic groups such as quaternary ammonium are introduced into starch, which has a basic structure in which multiple glucose units are linked via α-1,4-glucosidic bonds.

[0026] The cationic starch used in the present invention is represented by the following formula (I): [ka] Preferred is a cationic polymer represented by the formula:

[0027] The symbols in the above formula (I) have the following meanings. X -represents an anion derived from an inorganic acid or an organic acid. Examples of inorganic acids include hydrochloric acid, sulfuric acid, and nitric acid, and examples of organic acids include carboxylic acids such as acetic acid. The anion X in the above formula (I) - As for the ions, halide ions, especially Cl - is preferred. a and b represent the number of each monomer in the polymer and the ratio of each monomer. When representing the number of each monomer, the average molecular weight (weight average molecular weight: Mw) of the cationized starch represented by formula (I) is preferably 30,000 to 1,000,000, more preferably 100,000 to 500,000, so a and b take values ​​such that the average molecular weight falls within the above range. When representing the ratio of each monomer, for example, assuming that a+b=1, a is 0.6 to 0.9, preferably 0.7 to 0.8, more preferably about 0.75, and b is 0.4 to 0.1, preferably 0.3 to 0.2, more preferably about 0.25.

[0028] The cationic starch represented by formula (I) has the cosmetic ingredient name "hydroxypropyltrimonium starch chloride". Examples of products commercially available under this name include "Sensamer CI-50" (manufactured by NALCO Performance Products), "DOCCTARCH CP" (manufactured by DOC Japan), "Amilomer 25L" (manufactured by Graefe Chemie), "Amilomer 50M" (manufactured by Graefe Chemie), "Pharmal MS5940" (manufactured by Corn Products International), and "Excel FM-004" (manufactured by Nippon Starch Co., Ltd.), and these commercially available products can be used. Among these, "Sensamer CI-50" (average molecular weight = 200,000; a:b = 0.75:0.25) can be preferably used.

[0029] Cationic starch is used primarily as a hair conditioning agent as a cationic polymer together with cationic cellulose, polyquaternium, and the like. The fact that cationic starch has a virus inactivating effect is a surprising finding discovered for the first time by the present inventors.

[0030] The amount of cationic starch in the virus inactivating agent of the present invention is 0.1% by mass or more, preferably 0.15% by mass or more, more preferably 0.2% by mass or more, in terms of pure polymer content, based on the total amount of the virus inactivating agent. If the amount is less than 0.1% by mass, a sufficient virus inactivation effect cannot be obtained. The upper limit of the amount of cationic starch is not particularly limited, but is usually 5% by mass or less, preferably 3% by mass or less, more preferably 2% by mass or less.

[0031] In the present invention and this specification, the term "virus inactivation" means removing or significantly reducing the infectivity or proliferation ability of a virus. There are no particular limitations on the viruses that can be inactivated by the virus inactivating agent of the present invention, and various viruses can be inactivated regardless of the type of genome, the presence or absence of an envelope, etc.

[0032] For example, influenza A, B, C viruses, Isavirus, Quaranja virus, Thogoto virus, Rhinovirus, Poliovirus, Rotavirus, Norovirus, Enterovirus, Hepatovirus, Astrovirus, Sapovirus, Hepatitis E virus, Parainfluenza virus, Mumps virus, Measles virus, Human metapneumovirus, Respiratory syncytial virus, Nipah virus, Hendra virus, Yellow fever virus, Dengue virus, Japanese encephalitis virus, West Nile virus, Hepatitis B, C virus, Eastern and Western equine encephalitis virus, Rubella virus, Lassa virus, Junin virus, Machupo virus, Guanarito virus, Sabia virus, Crimean-Congo hemorrhagic fever virus, Hantavirus, Sin Nombre virus, Rabies virus, Examples of viruses to be inactivated include Ebola virus, Marburg virus, bat lyssavirus, human T-cell leukemia virus, human immunodeficiency virus, human coronavirus, SARS coronavirus, human porvovirus, polyomavirus, human papillomavirus, adenovirus, herpes virus, chickenpox, exanthema zoster virus, EB virus, cytomegalovirus, smallpox virus, monkeypox virus, cowpox virus, molassipox virus, and parapox virus. Preferably, the viruses to be inactivated are enveloped single-stranded RNA viruses, more preferably influenza viruses A, B, and C, isavirus, quaranja virus, and thogoto virus, which belong to the Orthomyxoviridae family, and particularly preferably influenza viruses.

[0033] The virus inactivating agent of the present invention is sufficiently effective when formulated with one or more essential oils selected from the group consisting of peppermint oil, eucalyptus oil, rosemary oil, sage oil, tea tree oil, shell ginger oil, peppermint oil, lemongrass oil, cajeput oil, niaouli-cineole oil, lime oil, lemon oil, lemon verbena oil, St. John's wort oil, ravinsara oil, rosewood oil, melissa / lemon balm oil, myrrh oil, mandarin oil, vetiver oil, frankincense oil, citronella oil, cardamom oil, and angelica oil, or cationic starch, each of which is formulated alone; however, a virus inactivating agent may also be formed by combining an essential oil with cationic starch as the active ingredient.

[0034] The present invention provides a skin topical preparation composition containing the above-mentioned virus inactivating agent. The "skin topical preparation composition" of the present invention may be any topical preparation composition that is applied to the skin (including the scalp), and may include, for example, cosmetics (including basic cosmetics and makeup cosmetics), cleansing agents, topical medicines, and topical quasi-drugs. The skin topical preparation composition of the present invention may be in a form consisting of only the above-mentioned virus inactivating agent, or may be in a form in which various components generally used in skin topical preparation compositions are appropriately blended as necessary.

[0035] For example, the skin topical preparation composition of the present invention may contain a lower alcohol (alcohol having 6 or less carbon atoms) such as ethanol. Lower alcohols such as ethanol are known to have an inactivating effect on various viruses including influenza viruses, and virus inactivation compositions containing a high amount of alcohol are also known. However, in the skin topical preparation composition of the present invention, when alcohol is added, the amount of alcohol added is preferably 50% by mass or less, preferably 40% by mass or less or 30% by mass or less, so that even those with sensitive skin can use the composition with peace of mind.

[0036] Other optional components that can be incorporated into the skin topical composition of the present invention include, for example, oils (animal and vegetable oils, mineral oils, ester oils, wax oils, silicone oils, higher alcohols, phospholipids, fatty acids, etc.), surfactants (anionic, cationic, amphoteric or nonionic surfactants), vitamins (vitamin A group, vitamin B group, folic acid, nicotinic acid, pantothenic acid, biotin, vitamin C group, vitamin D group, vitamin E group, ferulic acid, γ-oryzanol, etc.), ultraviolet absorbers (p-aminobenzoic acid, anthranil, salicylic acid, coumarin, benzotriazole, tetrazole, imidazoline, pyrimidine, dioxane, furan, pyrone, camphor, nucleic acid, allantoin, and the like). These derivatives, amino acid compounds, shikonin, baicalin, baicalein, berberine, etc.), antioxidants (stearic acid esters, nordihydroguaiaretic acid, dibutylhydroxytoluene, butylhydroxyanisole, parahydroxyanisole, propyl gallate, sesamol, sesamolin, gossypol, etc.), thickeners (hydroxyethyl cellulose, ethyl cellulose, carboxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, sodium carboxymethyl cellulose, hydroxypropyl cellulose, nitrocellulose, polyvinyl alcohol, polyvinyl methyl ether, polyvinylpyrrolidone, polyvinyl methacrylate, polyacrylates , carboxyvinyl polymers, gum arabic, gum tragacanth, agar, casein, dextrin, gelatin, pectin, alginic acid and its salts, etc.), moisturizing agents (propylene glycol, 1,3-butylene glycol, polyethylene glycol, glycerin, 1,2-pentanediol, hexylene glycol, chondroitin sulfate and its salts, hyaluronic acid and its salts, sodium lactate, etc.), water-soluble polymers, pH adjusters, preservatives and antifungal agents, colorants, refreshing agents, stabilizers, microbial culture metabolic components, blood flow promoters, anti-inflammatory agents, anti-inflammatory agents, antiallergic agents, amino acids and their salts, keratolytic agents, astringents, wound healing agents, deodorants and deodorants, various powdered components, etc. These may be blended singly or in combination of two or more.

[0037] The skin topical composition of the present invention may be in any dosage form, such as lotion, cream, ointment, milky lotion, foundation, oil, pack, soap (including medicated soap), body soap, lipstick, perfume, facial cleanser, deodorant (for armpit odor, foot odor, etc.), bath agent, shampoo, conditioner, hair tonic, hair spray, etc.

[0038] The external skin preparation composition of the present invention may be in the form of a solution, cream, paste, gel, foam, solid or powder depending on the dosage form. The skin external preparation composition of the present invention can be prepared using the above-mentioned virus inactivating agent as an essential component according to a conventional method appropriate for the dosage form and shape. EXAMPLES

[0039] The present invention will be described in more detail below with reference to examples, but the present invention is not limited thereto. In the examples, "%" means "% by mass" unless otherwise specified.

[0040] Example 1 Inactivation effect against influenza viruses (part 1) 1) Preparation of specimen (test solution) A virus inactivating agent sample (test solution) was prepared according to the formulation shown in Table 1 below.

[0041] [Table 1]

[0042] 2) Test method Influenza virus type A (H1N1 / PR / 8 / 34) strain was used as the test virus strain. Add 0.12 mL (1 x 10) of virus solution to 1.080 mL of each sample (test solution) shown in Table 1. 4pfu / mL) was added and reacted for 30 minutes, then serially diluted 10-fold in SCDLP medium and inoculated into canine kidney cells (MDCK) that had been cultured in advance in a 96-well plate. After culturing at 37°C and 5% CO2, the number of plaques formed was counted and the residual viral infectious titer was determined.

[0043] 3) Test results The results are shown in Table 2. As is clear from Table 2 below, the combination of four mint essential oils (mint oil, rosemary oil, eucalyptus oil, and sage oil) (sample 2) showed a log reduction in viral infectivity titer of about 4, indicating a high inactivating effect against influenza viruses. In contrast, in the other samples (3 to 8) in which the amount of limonene was reduced to less than 0.006 mass% by reducing the types of essential oils or the blended amounts of essential oils, no viral inactivating effect was observed in any case.

[0044] [Table 2]

[0045] Example 2 Inactivation effect against influenza viruses (part 2) 1) Preparation of specimen (test solution) A virus inactivating agent sample (test solution) was prepared according to the formulation shown in Table 3 below.

[0046] [Table 3]

[0047] 2) Test method The test method was similar to that described in Example 1 above.

[0048] 3) Test results The results are shown in Table 4. As is clear from Table 4 below, sample 10, which contained 0.24 mass% cationic starch (hydroxypropyltrimonium starch chloride) in terms of pure polymer content, had a log reduction in viral infectivity titer of 4 or more, and was found to have a very high influenza virus inactivation effect. In contrast, no virus inactivation effect was observed in sample 12, which contained the same amount (0.1 mass%) of cationic cellulose derivative (hydroxyethyl cellulose hydroxypropyltrimonium chloride) in terms of pure polymer content, and sample 11, which contained a smaller amount (0.024 mass%) of cationic starch than the effective amount.

[0049] [Table 4]

[0050] Other formulation examples of the external skin preparation composition according to the present invention are given below. (Formulation example 1) Skin topical agent (virus block mist) Ingredients Mass% Ethanol 20.0 Cationic starch(*) 1.0 Citric acid 0.02 Sodium citrate 0.08 water residue Total 100 (*)Sensamer CI-50

[0051] The skin topical preparation of Formulation Example 1 was discharged from a mist dispenser to obtain an antiviral mist. This formulation may also be used as a concentrate and made into an aerosol product using an appropriate compressed gas (nitrogen, LPG, carbon dioxide, etc.).

[0052] (Formulation Example 2) Skin topical agent (gel) Ingredients Mass% Ethanol 30.0 Peppermint 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 residue Fragrance 0.1 Total 100

[0053] (Formulation Example 3) Skin topical agent (gel) Ingredients Mass% Hydroxypropyl cellulose 0.5 Cationic Starch 1.0 water residue Total 100 (*)Sensamer CI-50

[0054] (Formulation Example 4) Skin topical agent (gel) Ingredients Mass% Ethanol 10.0 Peppermint oil 0.07 Rosemary oil 0.032 Sage oil 0.02 Eucalyptus oil 0.03 Carboxyvinyl polymer 0.5 Potassium hydroxide 0.2 Glycerin 10.0 PEG-60 hydrogenated castor oil 0.1 water residue Total 100

Claims

1. A virus inactivating agent comprising hydroxypropyltrimonium starch chloride.

2. The virus inactivating agent according to claim 1, wherein the virus is an enveloped single-stranded RNA virus.

3. The virus inactivating agent according to claim 2, wherein the enveloped single-stranded RNA virus is a virus belonging to the family Orthomyxoviridae.

4. The virus inactivating agent according to claim 3 , wherein the virus belonging to the Orthomyxoviridae family is an influenza virus.

5. A composition for inactivating viruses, comprising a virus inactivating agent according to any one of claims 1 to 4 in an amount of 0.1 mass% or more relative to the total amount of the composition.

6. The composition according to claim 5, further comprising an alcohol.

7. The composition according to claim 6, wherein the content of alcohol is 50% by mass or less.

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