AU2021396738A1

AU2021396738A1 - Skin sanitizing compositions containing manuka oil

Info

Publication number: AU2021396738A1
Application number: AU2021396738A
Authority: AU
Inventors: Stuart H. CAIRNS; Robert GIMOUR; Christine J. HAMES
Original assignee: Manuka Therapeutics Ltd
Current assignee: Manuka Therapeutics Ltd
Priority date: 2020-12-09
Filing date: 2021-12-09
Publication date: 2023-07-06
Also published as: AU2021396738A9; WO2022123313A1

Abstract

A skin sanitizing composition for treatment of a skin condition comprising a mixture of Leptospermum Scoparium oil (manuka oil) and an organic acid such as lactic acid.

Description

SKIN SANITIZING COMPOSITIONS CONTAINING MANUKA OIL

FIELD OF THE INVENTION

[001] The application relates to topical compositions for sanitizing the skin in mammals, including humans. More particularly, non-alcohol-based hand sanitizers that include natural ingredients including optional moisturizers or skin protectants incorporated into the sanitizer.

BACKGROUND

[002] One of the best and easiest ways of preventing bacteria or disease transmission is by routinely washing a person’s hands using soap and water. However, several situations arise where traditional washing is inconvenient or impossible. A number of companies have introduced hand sanitizing products designed to sanitize skin surfaces without the need for water or a means to dry a person’s hands.

[003] Skin sanitizing compositions have been produced that may be applied to a person's skin to rapidly kill and eliminate the presence of common bacterial. Such sanitizers can commonly be applied without the need for the addition of water to function and generally dry within the matter of seconds to eliminate 99% or more of common household bacterial that may be present on the skin. Sanitizer formulations are generally available in the form of a liquid, gel, or foaming composition. Such formulations typically include alcohol as the primary disinfecting agent.

SUMMARY

[004] The present disclosure generally relates to antimicrobial skin sanitizing compositions including natural, alcohol-free formulations that are effective in killing microorganisms present on a user’s skin. More particularly, the skin sanitizers include a combination of

Leptospermum Scoparium oil (manuka oil) and an organic acid (e.g., lactic acid) that provide an effective, rapid acting antimicrobial hand sanitizer to substantially eliminate the presence of bacteria on a user’s skin. In some embodiments, the disclosed hand sanitizing formulations may be substantially free of alcohol and/or include only natural ingredients. The disclosed hand sanitizers may also have a viscosity that prevents running when applied to a patient’s skin. Additionally, or alternatively, the disclosed skin sanitizing formulation may be used as a surgical preparation for a patient’s skin such as in cosmetic surgery. The surgical preparation formulations may be used in place of iodine or chlorhexidine products.

[005] In one embodiment in accordance with this disclosure, a skin sanitizing composition includes Leptospermum Scoparium oil (manuka oil) and an organic acid such as lactic acid. In some embodiments, the combination of manuka oil and organic acid (e.g. lactic acid) may provide a synergistic effect of rapidly eliminating the presence of more than about 99 % of common bacteria from a user’s skin. In some additional embodiments, the disclosed compositions may inhibit the grown of new bacteria on the user’s skin for an extended period of time.

[006] In some embodiments, the disclosed skin sanitizing composition may also include Nigella Sativa seed oil (black seed oil) or other oils described herein. The inclusion of black black seed oil may help provide excellent and sustained antimicrobial activity as compared to other alcohol-based compositions. In some such embodiments, the black seed oil, if present, may be included in an amount of about 0.1 wt.% to about 4 wt.% of the composition.

[007] The above summary is not intended to describe each disclosed embodiment, or every implementation of the embodiments disclosed herein. The description that follows more particularly exemplifies illustrative examples. In several places throughout the application, guidance is provided through lists of examples, which can be used in various combinations. In each instance, the recited list serves only as a representative group and should not be interpreted as an exclusive list. DEFINITIONS

[008] As used herein, “a,” “an,” “the,” “at least one,” and “one or more” are used interchangeably. Thus, for example, a composition that comprises “a” surfactant can be interpreted to mean that the composition includes “one or more” surfactants.

[009] As used herein, the term “consists substantially of’ means that at least 95 percent by weight (wt.%) the respective material is made of the recited component. For example, a sanitizing composition that consists substantially of vegan materials means that at least 95 wt.% of the composition is made of vegan materials.

[010] As used herein, the term “consists essentially of’ means that the respective material is formulated of the recited components, but also may include other contaminates that do not materially affect the physical or chemical properties of the material. In some embodiments, a composition that “consists essentially of’ a list of materials may include less than 0.5 wt.% other components.

[011] As used herein, the term “comprises” and variations thereof do not have a limiting meaning where these terms appear in the description and claims.

[012] As used herein, the term “essential oil,” “plant oil,” or “seed oil,” refers to a natural, plant-based oil. Unless indicated otherwise, such oils may be derived from a cold press process or a steam distillation. The method of producing such oils (e.g., steam distillation versus cold press) may alter the compositional makeup and physical and medicinal properties of the oil.

[013] As used herein, the terms “mixture” or “mixing” refers to a physical mixture or physically mixing (e.g., blending) two or more components together. Unless otherwise indicated, a mixture includes emulsions, heterogeneous mixtures, and homogeneous mixtures. [014] As used herein, the term “natural” refers to an excipient derived from a renewable source such as plants, insects, or animal-based sources, as opposed to synthetic or petroleumbased sources. For example, the phrase “natural oil” may include oils derived from plants, insects (e.g., bees), or animals. An excipient may still be considered “natural” even though the excipient may have undergone a chemical or physical extraction process. For example, essential oils are typically extracted from plants through a distillation process. Essential oils are still considered natural even though processing has occurred to isolate and purify the oil.

[015] As used herein, the terms “preferred” and “preferably” refer to embodiments that may afford certain benefits, under certain circumstances. However, other embodiments may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful and is not intended to exclude other embodiments from the scope of the disclosure.

[016] As used herein, the term “skin sanitizing composition” or “topical composition” refers to compositions designed to be applied to the skin of a patient and is not indented for internal consumption or use. Such compositions may include transdermal excipients (e.g., those that penetrate or pass through the layers of the epidermis) and may, in some embodiments, be applied to portions of the skin that include an open wound (e.g., laceration, abrasion, surgical incision, and the like). Skin sanitizing compositions may include, but are not limited to liquids, gels, liquid foams, lotions, ointments, solutions, sprays, or the like. The skin sanitizing compositions may be applied directly to the skin of a patient (e.g., direct application of a liquid) or indirectly to the skin of a patient (e.g., application via a sponge or dressing including the disclosed compositions thereon). In preferred embodiments, the disclosed skin sanitizing compositions are applied to undamaged skin.

[017] Also herein, the recitations of numerical ranges by endpoints include all numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.). Furthermore, disclosure of a range includes disclosure of all sub-ranges included within the broader range (e.g., 1 to 5 discloses 1 to 4, 1.5 to 4.5, 4 to 5, etc.).

DETAILED DESCRIPTION

[018] The embodiments described in this disclosure provide a skin sanitizing composition for the rapid disinfection of a person’s skin or other surfaces. Traditionally, skin sanitizing compositions rely on alcohol as the active disinfectant. Alcohol is effective in rapidly destroying common household bacterial and rapidly dries from a person’s skin making such compositions appealing in several situations. Such alcohol-based sanitizers typically require the use of anywhere from 60% to 95% alcohol, such as ethanol, in order to be effective. Unfortunately, alcohols at these levels can be very drying to the skin and cause irritation and pain if any damage or open wounds are present on the user’s skin.

[019] The present disclosure provides an alternative skin sanitizer formulation compared to such alcohol-based, iodine, or chlorhexidine formulations that uses manuka oil and organic acid as the primary disinfectant agents. The disclosed skin sanitizing compositions may be substantially free of alcohol (e.g., contains less than 5 wt.% alcohol, less than 1 wt.% alcohol, or less than 0.1 wt.% alcohol) while still being effective at eliminating 99% or more of common household bacteria from a use’s skin in less than five minutes after application. In some embodiments, the disclosed skin sanitizing compositions may provide better skin feel with natural based materials.

[020] In some embodiments, the disclosed skin sanitizing compositions include a unique mixture of Leptospermum Scoparium oil (manuka oil) and organic acid (e.g., lactic acid), and a carrier composition. As discussed further below, the inclusion of both manuka oil and organic acid may provide synergistic effects that provide a natural skin sanitizer formulation with beneficial skin feel characteristics compared to the use of either ingredient individually. The combination may also provide additional advantages as discussed further below. [021] In accordance with various embodiments, the skin sanitizing compositions disclosed include Leptospermum Scoparium oil (manuka oil). Manuka oil may be extracted from the leaves of a Leptospermum Scoparium plant using a steam distillation process. Leptospermum is the botanical name given to New Zealand’s Manuka tree. There are two species of Leptospermum in New Zealand, distinguishable by white or red pedals they produce. Leptospermum Scoparium or L. Scoparium refers to the white Manuka tree. While the Manuka tree is sometimes referred to as the New Zealand Tea Tree, oil extracted from the Manuka tree should not be confused with “tea tree oil.” In contrast to manuka oil, conventional tea tree oil is derived from the plant Melaleuca alternifolia, commonly found in Australia. Both the Melaleuca alternifolia and Leptospermum Scoparium belong to the myrtle family Myrtaceae commonly known as tea trees however, the oils extracted from each have comparatively different properties and chemical compositions.

[022] Manuka oil includes three major groups of compounds including monoterpenes, sesquiterpenes, and (3-triketones. Monoterpenes can include, for example, a- and (3-pinene. Sesquiterpenes can include, for example, a- and (3- eudesmol and (3- caryophyllene. (3- triketones include, for example, flavesone, iso-leptospermone, and leptospermone. Without being bound to a specific theory, the (3-triketones are believed to contribute to the exceptional antimicrobial properties of manuka oil and provide the synergistic effect when combined with organic acids such as lactic acid.

[023] The amount (3-triketones contained within manuka oil extract from the Manuka tree can depend on the region within New Zealand in which the Manuka tree is harvested. For example, Manuka trees harvested from the East Cape region of New Zealand contain the highest levels of (3-triketones compared to any other region, presumably due to the unique growing conditions of the region. The levels of (3-triketones within the manuka oil extracted from Manuka trees grown the East Cape region of New Zealand can be greater than 20 weight percent (wt.%), and in some examples greater than 30 wt.%, as compared to Manuka trees harvested from other regions of New Zealand which are typically far less than 20 wt.% and most commonly less than 5 wt.%. In some embodiments, the manuka oil used in the disclosed skin sanitizing compositions may be derived from Manuka tress sourced from the East Cape region of New Zealand.

[024] In various embodiments, the skin sanitizing compositions disclosed include manuka oil having a relatively high concentration of β-triketones. In some examples, the manuka oil may include at least 10 wt.% β-triketones, at least 25 wt.% β-triketones, at least 30 wt.% β- triketones, and most preferably at least 40 wt.% β-triketones. In some examples, a double steam distillation process may be used to extract and concentrate the manuka oil to increase the relative concentration of β-triketones within the oil. Sourcing the Manuka oil from Manuka trees harvested from the East Cape region of New Zealand provides a rich concentration of β-triketones within the extracted oil that likewise preservers the other components present in the extracted oil.

[025] Manuka oil is commercially available from Tairawhiti Pharmaceuticals Ltd. of East Cape, New Zealand and New Zealand Manuka Bioactives of Opotiki, New Zealand. New Zealand Manuka Bioactives offers different grades of manuka oil with different levels of β- triketones including, for example, MpTK™ 5+, MpTK™ 10+, MpTK™ 25+, MpTK™ 30+, and MPTK™ 40+, the #+ designation referring to the weight percent of β-triketones. New Zealand Manuka Bioactives characterizes its MPTK™ 25+ and higher grades as being sourced from the Manuka trees harvested from the East Cape region of New Zealand.

[026] As discussed further below, manuka oil has a high antimicrobial activity. In some embodiments, skin sanitizing compositions disclosed that include manuka oil may be useful in the rapid destruction of common household bacteria and/or preventing or inhibiting microbial growth on a user’s skin. Manuka oil exhibits good antimicrobial activity against a variety of microbes (e.g., bacteria, fungi, viruses, and the like) including, but not limited to,

Bacillus subtilis, Candida albicans, Clostridium species, Fusarium circinatum, gram positive bacteria, Herpes simplex -1 and -2 virus, Micrococcus luteus, Mycobacterium phlei, Sarcina lutea, Staphylococcus species, Legionella pneumophila, Listeria monocytogenes, and others.

[027] The disclosed skin sanitizing compositions include a suitable amount of manuka oil to produce the desired sanitizing effect. In some embodiments, the disclosed compositions may include about 0.05 wt.% to about 4 wt.% manuka oil, more preferably about 0.05 wt.% to about 0.4 wt.%. As described above, the manuka oil used may consist of a great selected that includes at least 25 wt.% β-triketones. Further the combination of manuka oil and organic acid (e.g., lactic acid) may provide a more effective sanitizing composition compare compositions including either ingredient independently or at comparable concentration levels. The disclosed skin sanitizing compositions include manuka oil as described herein (e.g., manuka oil having relatively high concentration of β-triketones) and one or more organic acids including, but not limited to lactic acid.

[028] In some embodiments, the selected organic acid may include lactic acid. Lactic acid, or lactate, is a naturally occurring chemical byproduct of anaerobic respiration. Lactic acid is produced naturally within the body and is commonly produce in the muscles during exercise. In contrast to other biocide agents, e.g., polychlorinated phenoxy phenols or isothiazolinones, lactic acid in the concentrations disclosed herein does not exhibit harmful side effects to human health or environmental toxicity. Lactic acid also has significant biocide activity against common household bacteria such as Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Enterococcus hirae, and the like. Lactic acid at moderate concentrations has been shown to provide good effectiveness against gram negative bacteria, but has diminished effectiveness against gram positive bacteria. Lactic acid may be produced through the fermentation process of natural and renewable resources. Microbial fermentation offers advantages, including cheap renewable substrates, low production temperatures, and low energy consumption.

[029] The disclosed skin sanitizing compositions include a suitable amount of organic acid (e.g., lactic acid) produce the desired sanitizing effect without. In some embodiments, the disclosed compositions may include a non-irritating amount of lactic acid. Additionally, or alternatively, the disclosed compositions may include about 0.1 wt.% to about 4 wt.% organic acid (e.g., lactic acid). The combination of manuka oil and organic acid (e.g., lactic acid) can allow the concentration of either ingredient or both ingredients to be substantially reduced while still obtaining the same of better sanitizing effectiveness as compared to similar compositions that include either ingredient independently at higher concentrations. Thus, by including both ingredients in the disclosed skin sanitizing formulation, less total active ingredient may be needed to obtain desired results, thereby reducing the overall costs to manufacture the disclose formulations.

[030] In some embodiments, the disclosed skin sanitizing compositions may also include one or more optional additional oil ingredients selected from black seed oil, palmarosa oil, sandalwood oil, thyme oil, lavender oil, patchouli oil, oregano oil, cardamom oil, spearmint oil, bisabolol, and gotukola extract. The disclosed ingredients may have synergistic effects when combined with manuka oil including, for example, providing higher efficacy against bacterial growth, promotion of skin health or wound healing properties, lower MIC, and the like.

[031] In accordance with various embodiments, the skin sanitizing compositions disclosed also include Cymbopogon Martini oil (palmarosa oil). Palmarosa oil may be extracted from the stem and/or grass leaves of a Cymbopogon Martini plant using a steam distillation process. Cymbopogon is the botanical name given to palmarosa grass, also known as Indian geranium, gingergrass, rosha and rosha grass that is native to India and Indochina. In some embodiments, the skin sanitizing compositions disclosed includes palmarosa oil and not black seed oil. In some embodiments, the disclosed compositions may include about 0.05 wt.% to about 4 wt.% manuka oil, more preferably providing about 0.5 wt.% to about 1.0 wt.% effective triketones, about 0.25 wt.% to about 0.5 wt.% palmarosa oil, and about 0.5 wt.% to about 1.5 wt.% lactic acid.

[032] In some embodiments, the skin sanitizing compositions disclosed also include black seed oil. Black seed oil may be extracted from the seeds of a. Nigella Sativa plant, which is a small plant with pale purple, blue, or white flowers that grows in Eastern Europe, Western Asia, and the Middle East. In some embodiments, the black seed oil may be extracted from the seeds using a cold press process.

[033] Black seed oil extracted from the seeds of a Nigella Sativa plant has a high p-cymene and thymoquinone content. Without being bound to a specific scientific theory, it is believed that the thymoquinone contributes to antimicrobial and anti-inflammatory properties of the black seed oil and provides the synergistic effect with manuka oil. Black seed oil may be used on skin to help prevent or inhibit bacterial growth and thereby promote skin health. The anti-inflammatory properties of black seed oil may also help to soothe the skin and reduce the chance of irritation. In skin sanitizing compositions, the black seed oil may also be useful for treating a large number of skin conditions including for example, acne, eczema, and the like thereby improving skin health.

[034] The combination of the additional oil ingredients described above and manuka oil may in certain compositions produce surprising synergistic effects when mixed together. For example, the mixture of black seed oil and manuka oil may increase the antimicrobial activity of the composition compared to either of the two oils individually. Additionally, the mixture of black seed oil and manuka oil shows a broader spectrum of antimicrobial activity and improved activity for longer periods of time. Without being bound to a specific scientific theory, it is believed that the mixture of the additional oil ingredients and manuka oil may not only inhibit the growth of microbes on the surface of the skin but also impede the chance of resistance mutation within the microbe. This may be due in part to the complexity and diversity of the various components contained within both oil extracts making it difficult for mutations of such microbes to develop resistance. Accordingly, the skin sanitizing compositions disclosed may remain more effective for a longer period of time with a single application.

[035] In some embodiments, the ratio of the additional oil ingredients to black seed oil, if present, may be about 1:1 to about 10:1 by weight. In preferred embodiments, the ratio of manuka oil to the additional oil ingredients may be adjusted to include a higher weight percent of manuka oil compared to the additional oil ingredients (e.g., about 4:1). Additionally or alternatively, the disclosed compositions may include additional oil ingredient, if present, in an amount of about 0.1 wt.% to about 4 wt.% of the composition.

[036] The skin sanitizing compositions disclosed also includes a carrier composition. The carrier composition may be water-based and include natural or vegan materials. For example, with modem sophisticated consumers, there exists a strong desire and preference to use natural, environmentally friendly materials rather than synthetic- or petroleum-based materials. Accordingly, in preferred embodiments, the carrier composition may consist substantially of or may consist essentially of natural or vegan based materials. Likewise, while typical hand sanitizer formulations use alcohol as the active disinfectant, alcohol has a tendency to dry a user’s skin or cause irritation of pain when applied, particularly if minor abrasions or open wounds are present on the user’s skin. Accordingly, the disclosed sanitizing compositions are preferably substantially free of alcohol (e.g., contains less 5% alcohol) or is completely free of alcohol (e.g., contains no measurable or only trace amounts of alcohol) and consist substantially of or consist essentially of natural or vegan based materials.

[037] In various embodiments, the carrier composition may include predominately water. Water-based compositions may be particularly useful in the formation of a liquid, gel, or foam thereby allowing for the majority of the composition to evaporate after application. In general, the disclosed compositions that include water may described as the composition including a selected percentage of the listed ingredients with the remainder of the balance being water.

[038] The carrier composition may also include one or more optional adjuvants including, but not limited to, one or more antioxidants, buffers, cleansers, emollients, foaming agents, fragrances, emulsifiers, exfoliants, humectants, hydrating agents, lubricants, natural oils, preservatives, surfactants, thickeners, or the like.

[039] In some embodiments, the disclosed skin sanitizing compositions may include one or more antioxidants and buffers that may help preserve the active ingredients or other adjuvants in the formulation. The buffers preferably help maintain the pH of the composition to be within a non-irritating amount relative to a patient’s skin. Suitable antioxidants may include ascorbic acid or ascorbyl palmitate (vitamin C or a derivative thereof), tocopherol (vitamin E), or the like. Tocopherol is typically derived from vegetable oils and possesses exceptional skin protection properties. For example, tocopherol may be used to absorb UV rays and prevent UV induced free radical damage to the skin as well as prevent other free radical induced damage. Tocopherol has anti-inflammatory properties and helps moisturize the skin. Ascorbyl palmitate is a fat-soluble derivative of ascorbic acid that acts as a free radical scavenger. Unlike the water soluble form (e.g., ascorbic acid), ascorbyl palmitate is able to enter the lipid cell membrane of the skin. Ascorbyl palmitate also supports immune cell activity and helps with the formation and maintenance of collagen within the skin. Tocopherol, ascorbyl palmitate, or ascorbic acid may be produced from natural and vegan- based sources. In preferred embodiments, the skin sanitizing composition includes tocopherol, ascorbyl palmitate, or both.

[040] In some embodiments, the disclosed skin sanitizing agents may include one or more exfoliants such as glyceryl oleate, or the like. The exfoliant may help remove dead skin cells during application to help promote skin health.

[041] In some embodiments, the skin sanitizing compositions may include one or more humectants, hydrating agents, or both. Such adjuvants may help moisturize the skin. Humectants in particular tend to pull water from deeper layers of the skin toward the surface to help hydrate the outer layers. Suitable humectants or hydrating agents may include betaine, glycerin, or the like.

[042] In some embodiments, the skin sanitizing compositions may include one or more surfactants or foaming agents. Such agents may improve the texture of the composition or generate a foam texture upon aeration. Suitable surfactants or foaming agents may include, for example, decyl glucoside, lauryl glucoside, and the like. Anionic surfactants include sodium lauryl sulphate (SLS) or sodium lauryl ether sulphate (SLES); non-ionic surfactants are, e.g., ethoxylated fatty alcohols (Pareth) or alkyl polyglycosides (APG). Another important class of surfactants are the zwitter-ionic betaines (for instance cocamidopropyl betaine, CAPB), which are often used in liquid soaps.

[043] Other useful optional excipients include nutrients and vitamins. In some embodiments, the carrier composition may include one or more vitamins A, C, D, E, or K. Preferred vitamins include vitamin A (e.g., retinol or retinol ester), vitamin C (e.g., ascorbyl palmitate or ascorbic acid), and vitamin E (tocopherol). In some embodiments, the skin sanitizing composition may also include at least vitamin A (e.g., retinol or retinol ester). The inclusion of retinol in the skin sanitizing composition in conjunction with the other materials disclosed above may be useful for promoting healthy skin.

[044] The skin sanitizing composition may be formulated into any suitable type of vehicle including, for example, liquids, creams, foams, gels, ointments, solutions, sprays, or the like. In preferred embodiments, the skin sanitizing composition is formulated into a topical liquid, topical foam, or topical gel. In either instance, the compositions are predominantly composed of a volatile materials (e.g., water) that evaporates upon application. The below examples provide skin sanitizing compositions containing the manuka oil and lactic acid in a carrier composition including other adjuvants. However, other base carrier compositions or different adjuvants that are not described herein may also be used provided they include the disclose manuka oil and organic acid compositions described herein.

[045] As discussed above, in preferred embodiments, the skin sanitizing composition consists substantially or essentially of natural or vegan based materials. However, several pharmaceutically active excipients may not be considered natural or vegan based excipients. In such embodiments, the skin sanitizing composition serving as the vehicle for the pharmaceutically active excipients may nevertheless be characterized as consisting substantially or essentially of natural or vegan based materials.

[046] The effectiveness of the disclosed skin sanitizing compositions may be determined using any suitable standard. Examples of such standard tests may include ASTM E2755 - Healthcare Handrub Test Method, which is designed to evaluate how effectively sanitizers inactivate transient bacteria over surfaces of a person’s hands and fingers using a process that simulates bacterial exposure and hand rub use in clinical settings. ASTM E2755 is specifically designed for hand rubs (sanitizers, rinses, sprays, foams, and wipes) that are used without soap and water. As a general overview, ASTM E2755 is conducted using hands of at least eight study participants who have not used antimicrobial products for at least one week prior to the test. After an initial wash, the participants’ hands are thoroughly contaminated with a test microorganism (e.g, Staphlylococcus aureus or Serratia marcescens) with a starting baseline number of microorganisms determined. Next, the participants hands are again subject to a cleansing wash and inoculation followed by application of the sanitizer composition to dry contaminated hands and the hands are rubbed thoroughly until the product dries. The activity of the product is determined following a single contamination/antiseptic exposure cycle (simulating occasional use) or after multiple (e.g., ten) contamination/antiseptic exposure cycles (simulating clinical use settings). The multiple application test also helps determine if there is a build-up of non-volatile components on the surface of the hands following repeated use. The effectiveness of the hand rub is determined by comparing the number of microorganisms recovered from contaminated hands after the use of the antiseptic product to the number recovered from contaminated hands that were not exposed to a hand rub product. Compositions exhibiting suitable sanitizing activity may exhibit a reduction of at least about 99% of microorganism recovery or at least about 99.9%.

[047] Other suitable tests may include ASTM E2276 methodology, which only uses fingerpads for testing but does not include a realistic hand rubbing step or ASTM E1053 which is standard practice to assess virucidal activity of compositions intended for disinfection of inanimate, nonporous environmental surfaces. The ASTM E2276 test may be more suitable for situations where the sanitizing composition is applied to the skin in preparation of surgical procedures (e.g., cosmetic surgery) or the like where hand rubbing does not occur.

EXAMPLES

[048] The following examples are offered to aid in understanding of the above embodiments and are not to be construed as limiting the scope thereof.

[049] EXAMPLE 1 - Sanitizing Liquid [050] A mixture of the following excipients was prepared to produce a skin sanitizing liquid composition.

[051] EXAMPLE 2 - Sanitizing Activity

[052] A preparation of the skin sanitizing composition of Example 1 is prepared and tested under against common bacteria. The results of the test is shown in Table 1.

CFU = Colony Forming Unit

[053] The results showed greater than 6 log reduction against E.coli, P. aeruginosa and E.hirae and 4.82 log reduction against S. aureus after 1 Minute contact time.

[054] EXAMPLE 3 - Virus neutralization

[055] A preparation of the skin sanitizing composition of Example 1 is prepared and tested under Reed & Muench LD50 Method against MHV-1. The results of the test is shown in Table 2.

Table 2.

Presence of virus in each response is recorded as Absence of virus in each response is recorded as “0”; Cytotoxic response is recorded as “C”; Calculated virus titre = 10^6.5TCID_50/0.1mL(6.50 log₁₀);Cell control - 4 wells with healthy cell monolayer.

[056] The results show virucidal efficacy against MHV-1 by achieving 4.00 log reduction in virus concentration after 1 minute exposure period at room temperature.

[057] EXAMPLE 4 - Minimum inhibitory concentration (MIC)

[058] The MIC test evaluates the lowest concentration of a test substance that prevents growth of the microbe. This is a measure of the antibiotic activity of the test sample. The disclosed skin sanitizing compositions may be tested for MIC using publicly available testing criteria. For example, test samples of the desired active compound can be prepared and serially diluted to give 11 or more different concentrations covering, for example, a 1000-fold range. For example, the test samples may include 50%-0.1% of a stock test sample (e.g., stock samples disclosed in Table 1) that are combined with select bacteria and fungi and incubated over a prescribe period of time. The MIC is useful to determine the lowest concentration of each test sample (mixture of active materials) that inhibits the growth of the microbe as determined by measurement of OD650nm using a Versa Max 96 well plate reader. Measurement of cell concentration can be made at several time points.

[059] Example stock sample solutions of active mixture that show promising initial results and may be viable for MIC testing are listed in Table 3.

[060] The methodology for growing the different micro-organisms available for evaluation in the MIC studies may be provided by the CLSI standards, Methods for Dilution Antimicrobial Susceptibility Tests for Bacteria that Grow Aerobically, Approved Standard, Ninth Edition, M07-A9, Vol. 32 No 2, January 2012; Methods for Antimicrobial Susceptibility Testing for Anaerobic Bacteria. Approved Standard, Ninth Edition, Mll-9, January 2018; and Performance Standards for Antifungal Susceptibility Testing of

Filamentous Fungi. First Edition, M61, November 2017. [061] Microorganisms that may be tested include, but are not limited to, Acinetobacter bawnanni; Candida albicans; Co lynebacteriwn diphtheria; Cutibacterium acnes; Enterococcus faecium; Escherichia coli; Proteus vulgans; Pseudomonas aeruginosa; Staphylococcus aureus; Staphylococcus aureus (MRSA); Stapllylococcus capilis; Stapllylococcus epidermidis; Stapllylococcus pseudinlermedius; Streptococcus pyogenes; Tricllophyton menlagrophytes; and Trichophywn rubrum. The samples in Table 3 above show promise against inhibiting growth of one or more of the above microorganisms.

[062] EXAMPLE 5 - Allergy and skin irritation tests

[063] Skin formulation compositions of the present disclosure are prepared and tested for evidence of allergic reaction and skin irritation on human skin. The formulations non- allergenic and non-irritating.

[064] EXAMPLE 6 - Treatment against viruses that cold sores or shingles

[065] Skin formulation compositions of the present disclosure are prepared and tested against viruses such as S. aureus, MRSA, S. epidermidis, S. pyogenes, C. acnes, Human alpha herpes virus 1, Human alpha herpes zoster virus attributed to aliments such as cold sores or shingles. The formulations demonstrate a therapeutic affect in the treatment of cold sores and shingles.

[066] EXAMPLE 6 - Treatment against skin conditions

[067] Skin formulation compositions of the present disclosure are prepared and tested against various skin ailments including skin aging, collagen production, scarring, UV damage, inflammation, itching, yeast or fungi growth, eczema, and/or psoriasis. The formulations demonstrate a therapeutic affects in the treatment of one or more of the above skin ailments.

[068]

[069] EXAMPLE 7 - Sanitizing Liquid 1L47/65 version] [070] A mixture of the following excipients was prepared to produce a skin sanitizing liquid composition in accordance with the disclosed embodiments and, in one preferable composition, provides triketones from the oils of about 0.66%, Lactic acid of about 0.99% and Palmarosa oil of about 0.34%.

[071] EXAMPLE 8 - Sanitizing Liquid [L50/140B version]

[072] A mixture of the following excipients was prepared to produce a skin sanitizing liquid composition in accordance with the disclosed embodiments and, in one preferable composition, provides triketones from the oils of about 1%, Lactic acid of about 0.99% and Palmarosa oil of about 0.34%.

Claims

What is claimed is:

1. A skin sanitizing composition comprising a mixture of:

Leptospermum Scoparium oil (manuka oil); an organic acid; and a water-based carrier composition.

2. The skin sanitizing composition of claim 1, further comprising Nigella Sativa seed oil (black seed oil).

3. The skin sanitizing composition of claim 1, further comprising Cymbopogon Martini oil (palmarosa oil).

4. The skin sanitizing composition of claim 1, further comprising one or more additional oil ingredients selected from the set consisting of black seed oil, palmarosa oil, sandalwood oil, thyme oil, lavender oil, patchouli oil, oregano oil, cardamom oil, spearmint oil, bisabolol, and gotukola extract.

5. The skin sanitizing composition of any one of the above claims, wherein the composition is substantially alcohol-free.

6. The skin sanitizing composition of any one of the above claims, wherein the skin sanitizing composition is in the form of a liquid, gel, or foam.

7. The skin sanitizing composition of any one of the above claims, wherein the organic acid comprises lactic acid.

8. The skin sanitizing composition of any one of the above claims, wherein the manuka oil comprises at least 5 weight percent (wt.%) β-triketones.

9. The skin sanitizing composition of claim 4, wherein the skin sanitizing composition comprises a ratio of manuka oil to additional oil ingredient of about 1:1 to about 10:1 by weight.

10. The skin sanitizing composition of claim 9, wherein the ratio of manuka oil to additional oil ingredient is about 4:1.

11. The skin sanitizing composition of any one of the above claims, wherein the skin sanitizing composition comprises: about 0.05 weight percent (]wt.%) to about 4 wt.% manuka oil based on a total weight of the skin sanitizing composition, and about 0.1 wt.% to about 4 wt.% lactic acid based on a total weight of the skin sanitizing composition.

12. The skin sanitizing composition of any one of the above claims, wherein the skin sanitizing composition provides at least a 99 % reduction in microbial activity.

13. A method for cleaning skin comprising: applying a skin sanitizing composition to an area of skin, the skin sanitizing composition comprising:

Leptospermum Scoparium oil (manuka oil); an organic acid; and a carrier composition, wherein the manuka oil and organic acid are mixed in the carrier composition.

14. The method of claim 11, wherein the composition is substantially alcohol -free, and wherein the skin sanitizing composition is in the form of a liquid, gel, or foam.

15. A method for manufacturing a skin sanitizing composition used to treat a skin condition comprising mixing Leptospermum Scoparium oil (manuka oil) and lactic acid into an alcohol-free carrier composition.