An antiperspirant composition

Abstract

Process for the preparation of the antiperspirant compositions and products comprising the antiperspirant compositions. Non-therapeutic use of the antiperspirant compositions.

Description

[0001] An Antiperspirant Composition

[0002] Field of the Invention

[0003] Antiperspirant compositions. Process for the preparation of the antiperspirant compositions and products comprising the antiperspirant compositions. Non-therapeutic use of the antiperspirant compositions.

[0004] Background of the Invention

[0005] It is desirable to provide compositions for antiperspirant products that comprise components that result in skin care benefits such as softening and soothing the skin. For example, antiperspirant compositions comprise an antiperspirant active component that comprises astringent antiperspirant metal salts. Astringent antiperspirant metal salts such as aluminum tend to cause de-moisturization and impairment of skin elasticity when applied to the skin, as described in WO 2019 / 038101 A1. Consequently, it is desirable that such antiperspirant compositions include components that provide skin care benefits to compensate for the astringency observed, these components may be a carrier oil that may also behave as an emollient.

[0006] The presence of carrier oils that are emollients in antiperspirant compositions do not appear to influence the melanin production in the area of the skin that comes into contact with the antiperspirant composition.

[0007] Emollients such as triglyceride oils, e.g.: sunflower seed oil including sunflower seed oil having a high unsaturated fatty acid content, are described as having an emollient benefit when used in personal care compositions (Akosun, AAK). However, although triglyceride oils are desirable to use due to their natural origin and consequent expected better skin compatibility [Chemistry and Technology of the Cosmetics and Toiletries Industry, second edition, Blackie Academic & Professional, 1992, p 23], preliminary formulation tests indicate that the addition of sunflower seed oil to an antiperspirant composition results in an equivalent amount of melanin production by the skin to the level that is observed if no antiperspirant composition is contacted with the skin.

[0008] Isopropyl isostearate (Crodamol, Croda) is also described as an emollient for use in personal care products; however, isopropyl isostearate is not known to influence melanin production by the skin. EP 2 949 312 A1 describes a list of ester oils including isopropyl isostearate as carriers; however, EP 2 949 312 A1 states that isopropyl myristate, an ester oil stated to have similar properties to isopropyl isostearate, when used as the sole carrier liquid, causes staining.

[0009] It is desirable to provide antiperspirant compositions that comprise an antiperspirant active component and that provide skin care benefits such as skin hydration, in addition to the reduction of melanin production by the skin at the location where the antiperspirant composition has been topically applied.

[0010] The present invention provides antiperspirant compositions comprising isopropyl isostearate that reduce and / or prevent perspiration and / or malodor, and reduces melanin production by the skin. Furthermore, a further reduction of melanin production by the skin is observed when the antiperspirant composition comprises both triglyceride oils and isopropyl isostearate. Furthermore, the present invention provides an anhydrous antiperspirant aerosol composition comprising an antiperspirant active component in combination with one or more triglyceride oils and isopropyl isostearate that reduces and / or prevents perspiration and provides skin care benefits such as skin hydration, in addition to reducing melanin production by the skin and reducing and / or preventing perspiration.

[0011] Furthermore, the present invention provides an anhydrous antiperspirant aerosol composition comprising an antiperspirant active component in combination with one or more triglyceride oils and isopropyl isostearate that reduces and / or prevents perspiration and reduces the staining on clothing observed when triglyceride oils are added to antiperspirant compositions. Furthermore, the present invention provides an anhydrous antiperspirant aerosol composition comprising an antiperspirant active component in combination with one or more triglyceride oils and isopropyl isostearate that reduces and / or prevents perspiration and provides skin care benefits such as skin hydration, in addition to reducing the staining on clothing observed when triglyceride oils are added to antiperspirant compositions. Furthermore, a synergistic effect of further reducing staining on clothes is observed when the anhydrous antiperspirant aerosol composition comprising an antiperspirant active component comprises both triglyceride oils and isopropyl isostearate.

[0012] The present invention provides an anhydrous antiperspirant aerosol composition comprising an antiperspirant active component in combination with one or more triglyceride oils and isopropyl isostearate that reduces and / or prevents perspiration, reduces melanin production by the skin and reduces the staining on clothing observed when triglyceride oils are added to antiperspirant compositions. Summary of the Invention

[0013] In a first aspect the invention is related to a base composition for an anhydrous antiperspirant aerosol composition wherein the base composition comprises from 5 wt% to 50 wt% antiperspirant active composition, from 0.1 wt% to 1.5 wt% suspending agent, from 35 wt% to 95 wt% carrier oil, wherein the carrier oil comprises isopropyl isostearate and one or more triglyceride oils, wherein the isopropyl isostearate is present in an amount of from 0.5 wt% to 15 wt% of the base composition and the of one or more triglyceride oils is present in an amount of from 0 wt% to 15 wt% of the base composition.

[0014] In a second aspect the invention relates to a process for the preparation of a base composition for an anhydrous antiperspirant aerosol composition. In a third aspect the invention relates to a process for the preparation of an anhydrous antiperspirant aerosol composition comprising the base composition and a process for the preparation of an anhydrous antiperspirant aerosol product comprising the anhydrous antiperspirant aerosol composition comprising the base composition.

[0015] In a fourth aspect the invention is related to an anhydrous antiperspirant aerosol composition comprising a base composition comprising from 5 wt% to 50 wt% antiperspirant active composition, from 0.1 wt% to 1.5 wt% suspending agent, from 35 wt% to 95 wt% carrier oil, wherein the carrier oil comprises isopropyl isostearate and one or more triglyceride oils, wherein the isopropyl isostearate is present in an amount of from 0.5 wt% to 15 wt% of the base composition and the of one or more triglyceride oils is present in an amount of from 0 wt% to 15 wt% of the base composition.

[0016] In a fifth aspect the invention relates to the non-therapeutic use of the base composition, the anhydrous antiperspirant aerosol composition or the anhydrous antiperspirant aerosol product for reducing or preventing perspiration and providing skin care benefits such as skin hydration and reduction of melanin production by the skin. Furthermore, the invention is related to the non- therapeutic use of the base composition, the anhydrous antiperspirant aerosol composition or the anhydrous antiperspirant aerosol product for preventing or reducing perspiration and reducing or preventing de-moisturisation of the skin and reduction of melanin production by the skin. The word "comprising" is intended to mean "including" but not necessarily "consisting of" or "composed of." In other words, the listed steps or options need not be exhaustive. It is noted that the examples given in the description below are intended to clarify the invention and are not intended to limit the invention to those examples per se.

[0017] Similarly, all percentages are weight / weight percentages unless otherwise indicated. Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material or conditions of reaction, physical properties of materials and / or use are to be understood as modified by the word "about".

[0018] Numerical ranges expressed in the format "from x to y" are understood to include x and y. When for a specific feature multiple preferred ranges are described in the format "from x to y", it is understood that all ranges combining the different endpoints are also contemplated. Numeric ranges expressed in the form 'between x and y' are understood to include x and y.

[0019] Detailed Description of the Invention

[0020] Anhydrous antiperspirant aerosol products comprise an anhydrous antiperspirant aerosol composition comprising a base composition and a liquified propellant gas. The base composition comprises all components of the anhydrous antiperspirant aerosol composition except the liquified propellant gas.

[0021] The term "anhydrous" should be understood to mean "essentially anhydrous", comprising less than 1 percent by weight of water, excluding any water that is chemically bound to solids within the composition, such as the antiperspirant active.

[0022] The base composition of the anhydrous antiperspirant aerosol composition is anhydrous in order for its use for an anhydrous antiperspirant aerosol composition.

[0023] In a first aspect the invention is related to a base composition for an anhydrous antiperspirant aerosol composition wherein the base composition comprises from 5 wt% to 50 wt% antiperspirant active composition, from 0.1 wt% to 1.5 wt% suspending agent, from 35 wt% to 95 wt% carrier oil, wherein the carrier oil comprises isopropyl isostearate and one or more triglyceride oils, wherein the isopropyl isostearate is present in an amount of from 0.5 wt% to 15 wt% of the base composition and the of one or more triglyceride oils is present in an amount of from 0 wt% to 15 wt% of the base composition. An essential component of base compositions of the invention is oil, also known as a carrier oil or fluid carrier. Herein, the term "oil" and signifies a water-insoluble organic material that is liquid at 20°C. Any material having a solubility of less than 0.1 g / 100g at 20°C is considered to be insoluble. Oils may be volatile or non-volatile and can be divided and silicone oils and non-silicone oils, for example: ester oils, triglyceride oils, volatile and non-volatile silicon or non-silicone oils.

[0024] The base composition preferably comprises from 35 wt% to 90 wt% carrier oil, more preferably from 40 wt% to 85 wt% carrier oil, and most preferably from 45 to 80 wt% carrier oil. In certain preferred embodiments the carrier oil is present at greater than 50 wt% and less than 75 wt% of the base composition.

[0025] The anhydrous aerosol composition comprises from 0.1 wt% to 60 wt% carrier oil, preferably from 5 wt% to 60 wt% carrier oil, more preferably at from 10 wt% to 55 wt% carrier oil, and most preferably at from 15 wt% to 50 wt% carrier oil. In certain preferred embodiments the carrier oil is present at greater than 20 wt% and less than 45 wt% by weight of the anhydrous aerosol composition.

[0026] Isopropyl isostearate is an ester oil and commercially available as e.g.: Crodamol, supplied by Croda. Triglyceride oil may be, for example: coriander seed oil, impatiens balsimina seed oil, parinarium laurinarium kernel fat oil, sabastiana brasilinensis seed oil, dehydrated castor seed oil, borage seed oil, evening primrose oil, aquilegia vulgaris oil, safflower oil, sunflower seed oil, high oleic sunflower seed oil, Helianthus Annuus Seed Oil and mixtures thereof. Other suitable oils are obtainable from hemp, and maize corn oil.

[0027] Triglyceride oil means a composition comprising triglycerides. Triglycerides are derivable from glycerol fatty acid residues. Preferably the triglycerides comprise from C12 to C22 fatty acid residues. C12 to C22 fatty acid residue means a carboxylic acid component of the triglyceride ester comprising an aliphatic carbon chain of from 12 to 22 carbon atoms in length. The fatty acid residues may be linear or branched, they may be saturated or unsaturated. The total number of carbon atoms being selected in conjunction with the extent of olefinic unsaturation and / or branching to enable the triglyceride to be liquid at 20°C. Preferably the one or more triglyceride oils comprise triglycerides comprising from 20 wt% to 90 wt% C12 to C22 fatty acid residues, more preferably from 30 wt% to 80 wt% C12 to C22 fatty acid residues, even more preferably from 35 wt% to 70 wt% C12 to C22 fatty acid residues.

[0028] In a preferred embodiment, the one or more triglyceride oils comprise triglycerides comprising from 20 wt% to 98 wt% C18 unsaturated fatty acid residues, more preferably from 30 wt% to 95 wt% C18 unsaturated fatty acid residues, even more preferably from 35 wt% to 92 wt% C18 unsaturated fatty acid residues. Preferably the C18 unsaturated fatty acid residues are selected from the group consisting of: oleic acid, linoleic acid, conjugated linoleic acids, linolenic acid, petroselenic acid, ricinoleic acid, linolenelaidic acid, trans 7-octadecenoic acid, parinaric acid, pinolenic acid, punicic acid, stearidonic acid and mixtures thereof. Particularly preferably the C18 unsaturated fatty acid residues comprise oleic, linoleic or oleic and linoleic fatty acid residues.

[0029] Preferably the triglyceride oil comprises triglycerides comprising from 20 wt% to 90 wt% oleic fatty acid residue, more preferably from 30 wt% to 95 wt% oleic fatty acid residue, even more preferably from 35 wt% to 90 wt% oleic fatty acid residue.

[0030] Preferably the one or more triglyceride oils is one or more triglyceride oil selected from the group consisting of sunflower seed oil, high oleic sunflower seed oil, Helianthus Annuus Seed Oil and mixtures thereof. Helianthus Annuus Seed Oil is commercially available, e.g.: as Akosun, supplied by AAK.

[0031] In an alternative embodiment of the invention, the carrier oil may be free of triglyceride oils; i.e.: the base composition comprises 0 wt% triglyceride oils.

[0032] The carrier oil may be free of triglyceride oils. In an embodiment of the invention the base composition comprises from 0.1 wt% to 5 wt% of one or more triglyceride oils, preferably from 1 wt% to 4 wt% of one or more triglyceride oils, more preferably from 2 wt% to 3 wt% of one or more triglyceride oils.

[0033] In an embodiment of the invention the base composition comprises from 0.5 wt% to 15 wt% isopropyl isostearate, preferably from 1 wt% to 12 wt% isopropyl isostearate, more preferably from 1.5 wt% to 10 wt% isopropyl isostearate. In an embodiment of the invention the base composition comprises from 1.5 wt% to 15 wt% isopropyl isostearate, preferably from 2 wt% to 7 wt% isopropyl isostearate, more preferably from 3 wt% to 6 wt% isopropyl isostearate.

[0034] In an embodiment of the invention the base composition comprises from 1.5 wt% to 10 wt% isopropyl isostearate and from 0.1 wt% to 5 wt% of one or more triglyceride oils. In a preferred embodiment of the invention, the base composition comprises from 2 wt% to 7 wt% isopropyl isostearate and from 1 wt% to 4 wt% of one or more triglyceride oils. In a preferred embodiment of the invention, the base composition comprises from 2 wt% to 6 wt% isopropyl isostearate and from 1 wt% to 4 wt% of one or more triglyceride oils. In a more preferred embodiment of the invention, the base composition comprises from 3 wt% to 6 wt% isopropyl isostearate and from 2 wt% to 3 wt% of one or more triglyceride oils.

[0035] In an embodiment of the invention the base composition comprises from 1.5 wt% to 10 wt% isopropyl isostearate and from 0.1 wt% to 5 wt% Helianthus Annuus Seed Oil. In a preferred embodiment of the invention, the base composition comprises from 2 wt% to 7 wt% isopropyl isostearate and from 1 wt% to 4 wt% Helianthus Annuus Seed Oil. In a preferred embodiment of the invention, the base composition comprises from 2 wt% to 6 wt% isopropyl isostearate and from 1 wt% to 4 wt% Helianthus Annuus Seed Oil. In a more preferred embodiment of the invention, the base composition comprises from 3 wt% to 6 wt% isopropyl isostearate and from 2 wt% to 3 wt% Helianthus Annuus Seed Oil.

[0036] The carrier oil comprises one or more oils, other than triglyceride oils, such as: volatile silicone oils, non-volatile silicone oils, volatile non-silicone oils, non-volatile non-silicone oils and mixtures thereof. The carrier oil comprises one or more oils, other than triglyceride oils, selected from the group consisting of volatile silicone oils, non-volatile silicone oils, volatile non-silicone oils, nonvolatile non-silicone oils and mixtures thereof.

[0037] Volatile silicone oils include, for example, liquid polyorganosiloxanes. Such materials may be cyclic or linear, examples include Dow Corning silicone fluids 344, 345, 244, 245, 246, 556, and the 200 series; Union Carbide Corporation Silicones 7207 and 7158; and General Electric silicone SF1202.

[0038] Non-volatile silicone oils are, for example, non-volatile dimethicones, often comprising phenyl or diphenylene substitution, for example Dow Corning 200 350 cps or Dow Corning 556. Some liquids may be commercially available as a blend of both volatile and non-volatile components, such as DC1501 (DOW). DC1501 is a blend of cyclopentasiloxane and dimethiconol.

[0039] The carrier oil may also comprise volatile non-silicone oils such as a fragrance oil, sometimes alternatively called a perfume oil. The fragrance oil may comprise a single fragrance or component more commonly a plurality of fragrance components. Herein, fragrance oils impart an odour, preferably a pleasant odour, to the composition. Preferably, the fragrance oil imparts a pleasant odour to the surface of the human body the composition is applied to the same.

[0040] The base composition comprises from 0 wt% to 4 wt% fragrance oil, preferably from 0.5 wt% to 3 wt% fragrance oil, more preferably from 0.8 wt% to 2 wt% fragrance oil.

[0041] Non-volatile non-silicone oils may comprise ester oils, ether oils and aliphatic alcohols.

[0042] Ester oils may also be known as aliphatic ester oils and comprise an alkanol having a carbon chain length of from C3 to C20 esterified with an alkanoic acid having a carbon chain length of from C8 to C20 alkanoic acid. The base composition may comprise ester oils selected from the group comprising isopropyl isostearate, isopropyl myristate, isopropyl palmitate, lauryl myristate, ethylhexyl stearate, isocetyl stearate, myristyl myristate and isostearyl isostearate.

[0043] Ester oils encompass triglycerides, for the purposes of this invention triglyceride oils that comprise from 20 wt% to 90 wt% C12 to C22 fatty acid residues are excluded from the definition of ester oilsEster oils that are triglycerides comprising C6 to C12 fatty acid residues that are carrier oils may be, for example: Caprylic / Capric Triglycerides.

[0044] Further suitable ester oils having a boiling point of above 150° C (and a melting point of below 20° C) include ester oils including alkyl or aryl benzoates such C12-15 alkyl benzoate, for example Finsolv TN™ or Finsolv Sun™. Preferably the carrier oil comprises Finsolv TN (Innospec).

[0045] Ether oils means alkyl ether oils having a boiling point of above 100° C and especially above 150° C, including polyalkyleneglycol alkyl ethers. Such ethers desirably comprise between 10 and 20 ethylene glycol or propylene glycol units and the alkyl group commonly contains from 4 to 20 carbon atoms. The preferred ether oils include polypropylene glycol alkyl ethers such as PPG- 14-butylether and PPG-15-stearyl ether. Preferably the carrier oil comprises PPG-14-butylether. Aliphatic alcohols are water-immiscible alcohol materials. Aliphatic alcohols may comprise isostearyl alcohol or octyldodecanol (Eutanol G, Sigma Aldrich). Preferably the carrier oil comprises octyldodecanol.

[0046] Antiperspirant active components may be aluminum halohydrate salts defined by the general formula Al2(OH)xCly. y may be from 0.5 to 1.8 and x+y=6. Preferably the antiperspirant active component is an aluminum chlorohydrate salt, for example: alumiunium chlorohydrate (ACH). Methods of preparation of alumiunium chlorohydrate (ACH) are described in WO 2007 / 048480 A1. Exemplary commercially available alumiunium chlorohydrate (ACH) is available as Micro-Dry (ex Elementis).

[0047] Aluminium halohydrate salts may be present in an activated form. Activated aluminium ch loro hydrates are made by methods known in the art EP 1 104282 A1. Exemplary commercially available activated alumiunium chlorohydrate (ACH) is available as ACH 7172 (ex Elementis).

[0048] Antiperspirant active components may be aluminium salts comprising aluminium sesquichlorohydrate (ASCH) of chemical formula AI2OH4.4CI1.6 to AI2OH4.9CI1.1. Most commercial ASCH samples are of chemical formula AI2OH4.7CI1.3 to AI2OH4.9CI1.1 and these are further preferred AASCH [Reach 301 and AASCH 3143 (ex Elementis)].

[0049] Particularly preferred ASCH salts comprise water-soluble calcium salt and amino acid, in particular glycine. Such salts are preferably of enhanced activity, achieved by heating the ASCH with the water-soluble calcium salt and amino acid at sufficient temperature and for sufficient time for the antiperspirancy performance of the ASCH to be improved. Such salts may also be known as activated ASCH (AASCH). Further details on this technology may be found in WO 2014 / 187685 A1 or WO2016 / 066528 A1 by Unilever.

[0050] Preferred aluminium halohydrate salts are selected from the group consisting of alumiunium chlorohydrate, activated alumiunium chlorohydrate, aluminium sesquichlorohydrate, activated aluminium sesquichlorohydrate.

[0051] In an embodiment of the invention the base composition comprises from, from 5 wt% to 50 wt% antiperspirant active component, preferably from 10 wt% to 45 wt% antiperspirant active component, more preferably from 15 wt% to 35 wt% antiperspirant active component. In a preferred embodiment of the invention the base composition comprises, from 5 wt% to 50 wt% activated aluminium sesquichlorohydrate, preferably from 10 wt% to 45 wt% activated aluminium sesquichlorohydrate, more preferably from 15 wt% to 30 wt% activated aluminium sesquichlorohydrate. Wherein the aluminium sesquichlorohydrate is activated with a water- soluble calcium salt and glycine according to, for example, WO 2014 / 187685 A1 or WO2016 / 066528 A1.

[0052] WO 2014 / 187685 A1 or WO2016 / 066528 A1 describe the spray dried powder produced from the aqueous solution of an activated antiperspirant salt activated as the particulate antiperspirant active ‘system’. Particulate antiperspirant active ‘system’ is intended to be synonymous with antiperspirant active component for the purposes of this invention.

[0053] In an embodiment of the invention the base composition comprises from 2 wt% to 8 wt% isopropyl isostearate, from 0.1 wt% to 5 wt% of one or more triglyceride oils, and 5 wt% to 50 wt% antiperspirant active composition.

[0054] In an embodiment of the invention the base composition comprises from 3 wt% to 7 wt% isopropyl isostearate, from 1 wt% to 4 wt% of one or more triglyceride oils, and 10 wt% to 45 wt% antiperspirant active composition.

[0055] In an embodiment of the invention the base composition comprises from 4 wt% to 6 wt% isopropyl isostearate, from 2 wt% to 3 wt% of one or more triglyceride oils, and 15 wt% to 30 wt% antiperspirant active composition.

[0056] The base composition may comprise additional components such as suspending agents, propylene carbonate and antioxidants.

[0057] The base composition further comprises a suspending agent. Preferred suspending agents are clays, particularly hydrophobically modified clays. Particularly preferred are hydrophobically modified hectorite or bentonite clays and especially preferred is disteardimonium hectorite (e.g. Bentone 38V, ex Elementis).

[0058] The base composition comprises from 1 wt% to 15 wt% suspending agent, preferably from 1 wt% to 8 wt% suspending agent, more preferably from 2 wt% to 6 wt% suspending agent, even more preferably from 2 wt% to 4 wt% suspending agent. It is often beneficial to calculate the proportion by weight of suspending agent by reference to the antiperspirant active, and in particular in a weight ratio of antiperspirant active: suspending agent of from 3:1 to 6:1.

[0059] Preferably, the anhydrous antiperspirant aerosol composition comprises from 0.1 wt% to 1.5 wt% suspending agent.

[0060] The base composition may comprise propylene carbonate. The anhydrous antiperspirant aerosol composition comprises from 0.001 wt% to 0.1 wt% propylene carbonate.

[0061] The amount of propylene carbonate is preferably selected in the range of from 25 to 75 percent of the weight of the suspending agent, is advantageously at least 35 percent and is often not more than 60 percent.

[0062] The base composition may comprise a preservative. Preferred preservatives include butylated hydroxytoluene. The anhydrous antiperspirant aerosol composition comprises from 0.25 wt% to 3 wt% butylated hydroxytoluene, preferably from 0.5 wt% to 1.5 wt%.

[0063] In a preferred embodiment the base composition for an anhydrous antiperspirant aerosol composition wherein the base composition comprises from 5 wt% to 50 wt% antiperspirant active composition, from 0.1 wt% to 1.5 wt% suspending agent, and from 35 wt% to 95 wt% carrier oil, wherein the carrier oil comprises isopropyl isostearate and one or more triglyceride oils, wherein the isopropyl isostearate is present in an amount of from 0.5 wt% to 15 wt% of the base composition and the of one or more triglyceride oils is present in an amount of from 0 wt% to 15 wt% of the base composition, wherein the carrier oil further comprises a one or more oils, other than triglyceride oils, selected from the group consisting of volatile silicone oils, non-volatile silicone oils, volatile non-silicone oils, non-volatile non-silicone oils and mixtures thereof.

[0064] In a preferred embodiment the base composition for an anhydrous antiperspirant aerosol composition wherein the base composition comprises from 5 wt% to 50 wt% antiperspirant active composition, from 0.1 wt% to 1.5 wt% suspending agent, and from 35 wt% to 95 wt% carrier oil, wherein the carrier oil comprises isopropyl isostearate and one or more triglyceride oils, wherein the isopropyl isostearate is present in an amount of from 0.5 wt% to 15 wt% of the base composition and the of one or more triglyceride oils is present in an amount of from 0 wt% to 15 wt% of the base composition, wherein the carrier oil further comprises a one or more oils, other than triglyceride oils, selected from the group consisting of liquid polyorganosiloxanes, dimethicones, fragrance oil, ester oils, ether oils and aliphatic alcohols.

[0065] Anhydrous antiperspirant aerosol products comprise an anhydrous antiperspirant aerosol composition comprising a base composition and a liquified propellant component. The liquified propellant component is a liquified propellant gas. Preferred liquefied propellant gases are hydrocarbons or halogenated hydrocarbon gases (particularly fluorinated hydrocarbons such as 1 ,1 -difluoroethane and / or 1 -trifluoro-2-fluoroethane) that have a boiling point of below 10°C and especially those with a boiling point below 0°C. It is especially preferred to employ liquefied hydrocarbon gases, and especially C3 to C6 hydrocarbons, including propane, butane, isobutane, pentane and isopentane and mixtures of two or more thereof. Of these especially preferred propellants, isobutane, isobutane / propane, butane / propane and mixtures of propane, isobutane and butane are most preferred.

[0066] The anhydrous antiperspirant aerosol composition comprises from 30 wt% to 99 wt% liquefied propellant gas, more preferably from 40 wt% to 95 wt% liquefied propellant gas, most preferably from 45 wt% to 65 wt%

[0067] Liquified propellant gas may also be known as a volatile propellant. Volatile propellant means a gas capable of being liquefied by compression and having a boiling point of less than 10°C and preferably less than 0°C.

[0068] The base composition has a viscosity of less than 15,000 cPs (mPa.s), preferably from 2000 to 10,000 cPs (mPa.s), measured at 20 °C using a Brookfield rotary viscometer, spindle TA at 10 rpm for 1 minute using the heliopath.

[0069] In a second aspect, the invention relates to a process for the preparation of a base composition, comprising the steps of: a. optionally blending silicone oils in a receptacle; b. adding all components excluding propylene carbonate, suspending agent and antiperspirant active composition to the silicone blend, mixing the blend after addition of each component; c. agitating the blend of step b.; d. adding the suspending agent to the blend of step c. and agitating the blend; e. adding propylene carbonate to the blend of step d. and agitating the blend; f. adding the antiperspirant active component portion-wise with stirring; g. agitating the blend of step f.

[0070] The agitation of all steps is preferably 6000 rpm for from 1 to at least 5 minutes.

[0071] Preferably the duration of agitation of step c, is 1 minute; step d. is two minutes; step e. is three minutes and step g. is at least 5 minutes.

[0072] Step a. may be carried out in a dispensing container.

[0073] Optionally, step g. may comprise the addition of a carrier oil component, such as isopropyl isostearate.

[0074] In a further aspect the invention relates to an anhydrous antiperspirant aerosol product and a process for the preparation of an anhydrous antiperspirant aerosol product.

[0075] Aerosol Product Manufacture

[0076] An aerosol product according to the present invention can be made conveniently by first blending together the ingredients of the base composition in a vessel, less any ingredient intended to be added later, agitating the mixture to suspend the particulate antiperspirant active, charging an aerosol canister with the mixed base composition and separately charging any other ingredient not blended previously into the base composition, charging either before, after or simultaneously, fitting and sealing the discharge line containing the valve onto the aerosol canister and injecting propellant gas into the canister through the discharge line.

[0077] The selection of the aerosol canister is at the discretion of the manufacturer of the aerosol product. Conveniently, the canister itself can be made from tin plate or aluminium. The discharge line includes a valve biased to the closed position, and may be depressed or tilt valve. The valve can be opened by depression or lateral movement as is determined by the valve of an actuator. The discharge line terminates in a spray nozzle which in conventional aerosol dispensers is moulded with the spray nozzle to form a depressor button or which in more recent developments such as in EP 1040055 or EP 1255682 comprises rotational or lateral relative motion of elements to prevent the valve being opened prematurely. The nozzle outlet has an internal diameter that is usually selected within the range of from 300 to 800 microns, particularly not greater than 600 microns and in many embodiments from 350 to 450 microns. This is particularly beneficial in that it enables the composition to be sprayed without an undue risk of blockage through nozzles of similar internal diameter currently employable with commercially available compositions.

[0078] A process for the preparation of an anhydrous antiperspirant aerosol product comprising the steps of: a. preparing a base composition; b. agitating the base composition of step a. c. simultaneously or sequentially with step b., introducing the base composition of step a. into a dispensing container; and, d. introducing liquified propellant component into the dispensing container.

[0079] Agitation of the base composition of step. b. enables distribution of any solid particulate material in the fluid.

[0080] Steps a. and b. may be simultaneous.

[0081] Step a. may be carried out in a dispensing container.

[0082] Non-therapeutic use of a base composition for an anhydrous antiperspirant aerosol composition wherein the base composition comprises from 5 wt% to 50 wt% antiperspirant active composition, from 0.1 wt% to 1.5 wt% suspending agent, and from 35 wt% to 95 wt% carrier oil, wherein the carrier oil comprises isopropyl isostearate and one or more triglyceride oils, wherein the isopropyl isostearate is present in an amount of from 0.5 wt% to 15 wt% of the base composition and the of one or more triglyceride oils is present in an amount of from 0 wt% to 15 wt% of the base composition, for the mitigation or reduction of perspiration and / or malodor.

[0083] Non-therapeutic use of a base composition for an anhydrous antiperspirant aerosol composition wherein the base composition comprises from 5 wt% to 50 wt% antiperspirant active composition, from 0.1 wt% to 1.5 wt% suspending agent, and from 35 wt% to 95 wt% carrier oil, wherein the carrier oil comprises isopropyl isostearate and one or more triglyceride oils, wherein the isopropyl isostearate is present in an amount of from 0.5 wt% to 15 wt% of the base composition and the of one or more triglyceride oils is present in an amount of from 0 wt% to 15 wt% of the base composition, for the mitigation or reduction of perspiration and / or malodor and increased skin care benefits such as skin hydration. Non-therapeutic use of a base composition for an anhydrous antiperspirant aerosol composition wherein the base composition comprises from 5 wt% to 50 wt% antiperspirant active composition, from 0.1 wt% to 1.5 wt% suspending agent, and from 35 wt% to 95 wt% carrier oil, wherein the carrier oil comprises isopropyl isostearate and one or more triglyceride oils, wherein the isopropyl isostearate is present in an amount of from 0.5 wt% to 15 wt% of the base composition and the of one or more triglyceride oils is present in an amount of from 0 wt% to 15 wt% of the base composition, for the mitigation or reduction of melanin production by the skin.

[0084] Non-therapeutic use of a base composition for an anhydrous antiperspirant aerosol composition wherein the base composition comprises from from 5 wt% to 50 wt% antiperspirant active composition, from 0.1 wt% to 1.5 wt% suspending agent, and from 35 wt% to 95 wt% carrier oil, wherein the carrier oil comprises isopropyl isostearate and one or more triglyceride oils, wherein the isopropyl isostearate is present in an amount of from 0.5 wt% to 15 wt% of the base composition and the of one or more triglyceride oils is present in an amount of from 0 wt% to 15 wt% of the base compositionfor the mitigation or reduction of melanin production by the skin, and reduction or prevention of perspiration and / or malodour.

[0085] Method for the reduction of melanin production by the skin wherein the base composition for an anhydrous antiperspirant aerosol composition wherein the base composition comprises from 5 wt% to 50 wt% antiperspirant active composition, from 0.1 wt% to 1.5 wt% suspending agent, and from 35 wt% to 95 wt% carrier oil, wherein the carrier oil comprises isopropyl isostearate and one or more triglyceride oils, wherein the isopropyl isostearate is present in an amount of from 0.5 wt% to 15 wt% of the base composition and the of one or more triglyceride oils is present in an amount of from 0 wt% to 15 wt% of the base composition, is topically applied to the skin.

[0086] Method for the reduction of melanin production by the skin and reduction or prevention of perspiration and / or malodour wherein the base composition for an anhydrous antiperspirant aerosol composition comprises from 5 wt% to 50 wt% antiperspirant active composition, from 0.1 wt% to 1.5 wt% suspending agent, and from 35 wt% to 95 wt% carrier oil, wherein the carrier oil comprises isopropyl isostearate and one or more triglyceride oils, wherein the isopropyl isostearate is present in an amount of from 0.5 wt% to 15 wt% of the base composition and the of one or more triglyceride oils is present in an amount of from 0 wt% to 15 wt% of the base composition., is topically applied to the skin. Method wherein the reduction of melanin production by the skin and reduction or prevention of perspiration and / or malodour is simultaneous.

[0087] Mitigation or reduction of melanin production by the skin is intended to mean mitigation or reduction of melanin synthesis in the skin.

[0088] Topical application

[0089] The base composition of the instant invention can be sprayed onto skin, and particularly into the underarm (axilla) in a conventional manner for spraying liquid compositions. Very conveniently, the base composition can be mixed with a liquified propellant (forming the anhydrous antiperspirant aerosol composition) prior to being sprayed from an aerosol canister. The canister is desirably held at a distance of between 12 and 18 cms from the armpit and the valve in the discharge line opened. The composition can be sprayed at the discretion of the user for a conventional period of time, such as from about 2 to 5 seconds per armpit. 1 to 4.

[0090] Cyclopentasiloxane and the cyclopentasiloxane and dimethicone blend (DC1501) were weighed into a beaker and mixed with the aid of a spatula. PPG-14 Butyl Ether, one or more triglyceride oils, C12-15 Alkyl Benzoate and octyldodecanol, were added to the beaker independently and the contents mixed with the aid of a spatula after each component was added. BHT was added to the beaker. The contents of the beaker were then sheared at 6000 rpm, for 1 minute, using high shear mixer (Silverson L4RT), fitted with 1 " head. The disteardimonium hectorite, was added to the beaker and mixed with the aid of a spatula. The contents of the beaker were sheared at 6000 rpm, for 2 minutes. Propylene Carbonate and Fragrance were added, and the contents of beaker sheared at 6000 rpm for a further 3 minutes. The antiperspirant active was added slowly and in stages and the contents of the beaker were mixed with a spatula after each addition. Once all of the antiperspirant active had been added to the beaker, the contents of beaker were sheared at 6000 rpm for at least 5 minutes. Isopropyl isostearate was added with mixing with the aid of a spatula. Table 1 :

[0091] Method for Testing Melanin Production

[0092] The method for testing inhibition of melanin production is an in vitro method for measuring the amount of melanin produced by the skin in the form of a living skin equivalent (LSE), in particular when contacted with the deodorant and / or antiperspirant or composition.

[0093] The control example is an untreated LSE and produces approximately 35 micro gram melanin I micro litre total protein. The second positive control, 2% Kojic Acid (5-Hydroxy-2-Hydroxymethyl-4-Pyrone: CAS number 501-30-4) is used as a depigmenting agent. It has been described as an effective inhibitor of tyrosinase and therefore melanin production (‘An Updated Review of Tyrosinase Inhibitors’ I nt J Mol Sci. 2009 Jun; 10(6): 2440-2475).

[0094] Example 1 demonstrates that the antiperspirant composition reduces the production of melanin in the LSE that it is applied to. The melanin is measured as 32.9 micro gram I micro litre protein (normalised data).

[0095] Example 2 demonstrates that the antiperspirant composition comprising triglyceride oils, i.e.: Helianthus Annuus Seed Oil, shows no significant change in the production of melanin in the LSE that it is applied to. The melanin is measured as 34.4 micro gram I micro litre protein.

[0096] Example 3 demonstrates that the antiperspirant composition comprising isopropyl isostearate, significantly reduces the production of melanin in the LSE that it is applied to. The melanin is measured as 30.3 micro gram I micro litre protein.

[0097] Example 4 demonstrates that the antiperspirant composition comprising the combination of triglyceride oils and isopropyl isostearate, i.e.: Helianthus Annuus Seed Oil and isopropyl isostearate, further reduces the production of melanin in the LSE that it is applied to in. The melanin is measured as 29.1 micro gram I micro litre protein.

[0098] Examples 3 and 4 demonstrate that antiperspirant compositions comprising isopropyl isostearate surprisingly reduce the production of melanin in a LSE that it is applied to.

[0099] In addition, the combination of isopropyl isostearate and triglyceride oils reduces the amount of melanin in the LSE even further. Figure 1 is a shows the results of Ex 1 to 4.

[0100] Method for Testing Yellow Stain Value on Cloth with Number of Washes

[0101] Fabric was cut into square pieces (swatches) and added to a 96 well plate.

[0102] Model sebum (10 micro litres), base composition (Ex 1 to 4) (40 micro litres) and artificial sweat (20 micro litres) were dosed (Nordson pulse microdosing) into the 96 well plate comprising the fabric and incubated (Thermo Scientific Heraeus Oven) for 90 minutes at 38 °C. Non-bio clothes washing detergent [Persil non-bio liquid] 5% aqueous solution, 150 micro litres) was added and the mixture was agitated for 15 minutes at 40°C.

[0103] The plates were rinsed with 20FH water (with Biotek automated washer) and dried for 7 days at 55°C and the procedure was repeated a further three times (washes). Figure 2 shows the increase in yellow stain value with increasing number of washes, from 1 to 4 washes.

[0104] Arixscan F2 Microtek was used to measure the stain intensity (yellow stain value) on the fabric swatches. L*, a*, b* were measured at three different areas of the stained and untreated fabrics. Delta b* was calculated subsequently. A corresponding method is described in WO 2022 / 122884 A1.

[0105] Db values correspond to the change in yellowness versus wash 0. Delta b increases with increasing yellow staining.

[0106] Results:

[0107] The method for testing yellow stain value is a model for the contact of cloth with, for example, an axilla area of the skin of a person that secretes sweat and sebum, and that has been contacted with the anhydrous antiperspirant aerosol composition. The yellow stain value is a measure of the degree of undesired residue on the cloth.

[0108] Example 2 demonstrates that a base formulation comprising triglyceride oil (2.9 wt%) and antiperspirant active component (23.8 wt%) increases the amount of yellow staining of cloth when subjected to the method of testing Yellow Stain Value on Cloth with Number of Washes as described above. The db value of 2.7 db is measured after 4 washes. This is an increase in comparison to the control base formulation example (Example 1) that does not contain triglyceride oil or isopropyl isostearate (1.7 db after 4 washes).

[0109] Examples 3 and 4 demonstrate that a base formulation comprising isopropyl isostearate (Example 3) or triglyceride oil and isopropyl isostearate (Example 4) are observed to have a reduced amount of yellow staining after 4 wash cycles (1.5 db and 1.5 db, respectively) in comparison to the control, Example 1.

Claims

Claims1 . A base composition for an anhydrous antiperspirant aerosol composition wherein the base composition comprises from 5 wt% to 50 wt% antiperspirant active composition, from 0.1 wt% to 1.5 wt% suspending agent, and from 35 wt% to 95 wt% carrier oil, wherein the carrier oil comprises isopropyl isostearate and one or more triglyceride oils, wherein the isopropyl isostearate is present in an amount of from 0.5 wt% to 15 wt% of the base composition and the of one or more triglyceride oils is present in an amount of from 0 wt% to 15 wt% of the base composition.

2. A base composition according to claim 1 , wherein the one or more triglyceride oils comprise from 20 wt% to 98 wt% C18 unsaturated fatty acid residues.

3. A base composition according to claim 1 or 2, wherein the one or more triglyceride oils is selected from the group consisting of sunflower seed oil, high oleic sunflower oil, Helianthus Annuus Seed Oil and mixtures thereof.

4. A base composition according to claims 1 to 3 comprising from 0.1 wt% to 5 wt% ofHelianthus Annuus Seed Oil and from 2 wt% to 8 wt% isopropyl isostearate.

5. A base composition according to claims 1 to 4, wherein the antiperspirant active composition comprises an aluminum halohydrate salt.

6. A base composition according to claims 1 to 5, wherein the antiperspirant active composition comprises activated aluminum sesquichlorohydrate.

7. A base composition according to claims 1 to 6, wherein the suspending agent is selected from the group consisting of hectorite clay and bentonite clay.

8. A base composition according to claims 1 to 7, wherein the carrier oil further comprises a one or more oils, other than triglyceride oils, selected from the group consisting of liquid polyorganosiloxanes, dimethicones, fragrance oil, ester oils, ether oils and aliphatic alcohols.

9. A base composition according to claims 1 to 8, further comprising cyclopentasiloxane, dimethiconol, PPG-14 butyl ether and C12 to C15 alkyl benzoate.

10. An anhydrous antiperspirant aerosol composition comprising from 1 wt% to 70 wt% base composition according to claims 1 to 9 and from 30 wt% to 99 wt% liquified propellant gas.

11. An anhydrous antiperspirant aerosol product comprising the anhydrous antiperspirant aerosol composition according to claim 10 housed in a device suitable for discharging the anhydrous antiperspirant aerosol composition.

12. A process for the preparation of a base composition according to claims 1 to 9, comprising the steps of: a optionally blending any silicone oils in a receptacle; b adding the one or more triglyceride oils, isopropyl isostearate, optional non-volatile oils and optional preservative, mixing the blend after addition of each oil and mixing the blend after addition of the optional preservative; c agitating the blend of step b.; d adding suspending agent to the blend of step c. and agitating the blend; e optionally adding propylene carbonate to the blend of step d. and agitating the blend; f adding antiperspirant active composition portion-wise with stirring; g agitating the blend of step f.

13. A process for the preparation of an anhydrous antiperspirant aerosol product according to claim 12 comprising the steps of: a preparing a base composition according to claim 11 ; b agitating the base composition of step a.; c introducing the base composition of step b. into a dispensing container; and, d introducing liquified propellant gas into the dispensing container.

14. A process according to claim 13, wherein steps a. and b. are simultaneous.

15. Non-therapeutic use of a base composition according to claims 1 to 9 or an anhydrous antiperspirant aerosol composition according to claim 10 or an anhydrous antiperspirant aerosol product according to claim 11 for the mitigation or reduction of melanin production by the skin.

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