Deodorant stick composition comprising an activated aluminium sesquichlorohydrate

Abstract

A deodorant stick composition comprising an activated aluminium sesquichlorohydrate, a C15-C19 alkane hydrocarbon and a fragrance comprising one or more components selected from limonene, dihydromyrcenol, benzyl acetate, citronellol, linalyl acetate, alpha-methyl ionone, and hexyl cinnamal.

Description

[0001] DEODORANT STICK COMPOSITION

[0002] Field of the Invention

[0003] The present invention relates to deodorant stick compositions delivering pleasant fragrance both on initial application and long after.

[0004] Background

[0005] WO 2019 / 091855 A1 (Unilever, 2019) discloses deodorant compositions comprising activated aluminium sesquichlorohydrate which reduce malodour caused by Staphylococci bacteria on the surface of human body.

[0006] WO 2024 / 132397 A1 (Unilever 2024) discloses aerosol compositions comprising an activated aluminium sesquichlorohydate and a carrier oil which is free from volatile cyclic silicone oil and which comprises a C12-C16 branched chain alkane having a refractive index within 0.13 of that of the AP active.

[0007] Summary of the Invention

[0008] It is an object of the invention to provide a deodorant stick composition which delivers a pleasant fragrance both on initial application and long after.

[0009] It is a further object of the present invention to provide a deodorant stick composition which does not require the presence of a silicone oil.

[0010] It is a further object of the present invention to provide a deodorant stick composition which delivers and maintains a fresh, floral and / or fruity odour perception.

[0011] It is a further object of the present invention to provide a deodorant stick composition that also delivers a reduced perspiration benefit.

[0012] In a first aspect of the invention there is provided a deodorant stick composition comprising an activated aluminium sesquichlorohydrate of formula AI2OH4.4CI1.6 to AI2OH4.9CI1.1, a C15-C19 alkane hydrocarbon and a fragrance comprising one or more components selected fromlinalool, limonene, dihydromyrcenol, benzyl acetate, citronellol, linalyl acetate, alpha-methyl ionone, and hexyl cinnamal.

[0013] In a second aspect of the invention there is provided a method of manufacture of an anhydrous AP stick composition according to the first aspect of the invention.

[0014] In a third aspect of the invention there is provided a non-therapeutic method of achieving improved odour perception on surface of the human body comprising the topical application of a deodorant stick composition according to the first aspect of the invention.

[0015] In a fourth aspect of the invention there is provided the non-therapeutic use of a deodorant stick composition according to the first aspect of the invention to improve odour perception on surface of the human body following topical application thereof.

[0016] Detailed Description

[0017] Herein, the term “anhydrous” should be understood to mean “essentially anhydrous”, comprising less than 1% by weight of water, excluding any water that is chemically bound to solids within the composition, such as the AP active.

[0018] Herein, topical application refers to application to the skin of the human body, in particular to the underarm regions of the human body.

[0019] Herein, deodorant actives are materials that reduce malodour on the skin of the human body, typically following topical application.

[0020] Herein, a hydrocarbon is a material consisting solely of carbon and hydrogen atoms and a hydrocarbon has carbon atoms arranged in a saturated linear, branched or cyclic chain. A CISCI 9 hydrocarbon has from 15 to 19 carbon atoms.

[0021] Herein, methods and uses should be understood to be cosmetic methods / uses, i.e. non-therapeutic methods / uses. Likewise, compositions of the invention are cosmetic, i.e. non-therapeutic compositions.

[0022] Herein, all percentages, parts, and ratios are by weight, unless otherwise indicated.Herein, references to an amount of a material or materials refer to the total amount of material(s) of the type indicated.

[0023] Herein, references to an amount of a material are with reference to the total composition of which it is a part, unless otherwise indicated.

[0024] Herein, “application” and “applied” relate to application to the skin of the human body, in particular the underarm regions, unless the context dictates otherwise.

[0025] Herein, features expressed as “preferred” with regard to a particular aspect of the invention should be understood to be preferred with regard to each aspect of the invention.

[0026] Herein, preferred, particularly preferred and especially preferred features of the invention are particularly preferred when used in combination with other preferred, particularly preferred, and especially preferred features of the invention.

[0027] Herein, “ambient conditions” refer to 20°C and 1 atmosphere pressure, unless otherwise indicated.

[0028] Herein, 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.

[0029] Herein, except in the examples or where otherwise explicitly indicated, all numbers in this description and claims indicating amounts of material, physical properties of materials and / or use are to be understood as modified by the word “about”.

[0030] Herein, 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.

[0031] Cosmetic stick compositions are typically wiped onto the surface of the human body and it is desirable for them to deliver a pleasant odour / fragrance. A favorable perception of the fragrance delivered shortly after application is a key factor in consumer’s purchase and re-purchase decision of such products. It is also important how the fragrance is perceived at extended times after application of the composition.

[0032] The deodorant compositions of the invention deliver a pleasant fragrance both on initial application and long after. They are able to this to do this without the need for a silicone carrier oil in the composition, using a C15-C19 alkane hydrocarbon carrier oil instead.

[0033] A key feature of the invention is the use of particular fragrance components having fresh, fruity and / or floral odour profiles (vide infra).

[0034] A further key feature is the use of a deodorant active that is highly effective at preventing malodour development on the surface of the human body through its remarkable antimicrobial properties, targeting the microbes on the skin surface responsible for the transformation of odour precursors into malodourous body odours. By using such an active, the pleasant initial fragrance delivered can be maintained for a considerable time, without being masked by body malodour.

[0035] The deodorant active used in the invention is an activated aluminium sesquichlorohydrate (ASCH) salt, the active comprising ASCH of formula AI2OH4.4CI1.6 to AI2OH4.9CI1.1, a water-soluble calcium salt and an amino acid. The water-soluble calcium salt and an amino acid “activate” the ASCH, i.e. increase its efficacy. Such actives also act as to reduce perspiration.

[0036] Activated ASCH salts as used herein are described in EP 2,999,452 B1 (Unilever, 2017), EP 3,212,296 B1 (Unilever, 2019) and in other publications.

[0037] The strong antimicrobial properties of the deodorant active used in the invention are described in WO 2019 / 091855 A1 (Unilever, 2019) mentioned in the background section. It was found to be significantly more effective than the widely used active aluminum chlorohydrate. The benefit was seen not only in terms of reduced bacterial numbers, but also in terms of reduced malodour in the underarm, a considerable time after application (24 hours).

[0038] The ASCH has the formula AI2OH4.4CI1.6 to AI2OH4.9CI1.1. Most commercial ASCH samples are of formula AI2OH4.7CI1.3 to AI2OH4.9CI1.1 and it is preferred to have such ASCH salts.The water-soluble calcium salt is preferably used at such a level that the molar ratio of calcium to aluminium is at least 1 :40, more preferably at least 1 :30 and most preferably at least 1 :20. It is not advantageous to have the calcium concentration in excess of the aluminium concentration; indeed, it is preferred that the calcium concentration is no more than half that of the aluminium concentration and more preferred that it is no more than a fifth of said concentration. For the preferred molar ratios of calcium to aluminium of at least 1 :40 and at least 1:20, it is independently preferred that this ratio is no greater than 1:2 and more preferred that it is no greater than 1 :5.

[0039] In particularly preferred embodiments, the molar ratio of calcium to aluminium is at least 1:15 and preferably no greater than 1:5 and in especially preferred embodiments it is at least 1:10 and preferably no greater than 1 :5.

[0040] A preferred water-soluble calcium salt for use in the invention is calcium chloride.

[0041] Herein, references to molar amounts and ratios of “aluminium” are calculated on the basis of mono-nuclear aluminium, but include aluminium present in poly-nuclear species; indeed, most of the aluminium in the salts of relevance is present in poly-nuclear species.

[0042] The amino acid is preferably used at such a level that the molar ratio of amino acid to aluminium is at least 1:20, more preferably at least 1:10 and most preferably at least 1:5. It is not advantageous to have the amino acid concentration in excess of the aluminium concentration; hence, the molar amino acid to aluminium is preferably from 1:20 to 1:1, more preferably from 1:10 to 1:1 and most preferably from 1:5 to 1:1.

[0043] In particularly preferred embodiments, the molar ratio of amino acid to aluminium is at least 1:4 and preferably no greater than 1:1 and in especially preferred embodiments it is at least 1:3 and preferably no greater than 1:1.

[0044] In preferred embodiments, the molar ratio of calcium to aluminium is at least 1:40 and the molar ratio of amino acid to aluminium is at least 1 :20. In further preferred embodiments the molar ratio of calcium to aluminium is at least 1:20 and the molar ratio of amino acid to aluminium is at least 1:10. In particularly preferred embodiments the molar ratio of calcium to aluminium is from 1:20 to 1:5 and the molar ratio of amino acid to aluminium is from 1:10 to 1:1.The above indicated preferences for calcium to aluminium molar ratio and / or amino acid to aluminium molar ratio lead to compositions of higher Band III content (vide infra) and, in general, higher antiperspirancy performance. It will be noted that higher Band III content is generally indicative of higher antiperspirancy performance.

[0045] Preferred amino acids for use in the invention are glycine, alanine, valine and proline. A particularly preferred amino acid for use in the invention is glycine.

[0046] The presence of the water-soluble calcium salt and amino acid lead to activation of the deodorant salt, which typically involves an increase in its Band III content (vide infra). In preferred embodiments, an aqueous solution of the deodorant salt is heated with the water-soluble calcium salt and glycine to achieve activation.

[0047] The content of “Band III material” in a deodorant salt may be determined by SEC (Size Exclusion Chromatography) analysis. The SEC technique is well known in the art and is described in further detail in US 4,359,456 (Gosling). The SEC band commonly referred to as Band III is designated as “Peak 4” in EP 1,104,282 B1 by Gillette.

[0048] Herein, “Band III content” refers to the integrated area in the Band III region of the SEC chromatograph relative to the total integrated area in all of the regions corresponding to aluminium species; that is to say, Bands I, II, III, and IV.

[0049] In preferred embodiments of the invention, compositions according to the invention have a deodorant active having a Band III content of at least 30% and more preferably at least 50%.

[0050] The deodorant active used in the invention is preferably a “milled” active, meaning that it has been ground down, typically to a relatively fine powder, and often following spray drying of an aqueous solution of the active. The milling produces an active that comprises non-hollow particles and this is a preferred feature of the invention, as it can aid in reducing white marks [see EP 2,999,452 B1 (Unilever, 2017)]. It is preferred that the active has an Rl of from 1.52 to 1.57, more preferably 1.53 to 1.55 and most preferably about 1.54.

[0051] The milled active, when employed, preferably has a mean particle size (D50) of at least 6 microns, preferably from 6 to 25 microns, and more preferably from 7 to 15 microns.Herein, mean (D50) particle sizes may be measured using (laser) light scattering techniques, for example using a Mastersizer instrument, obtainable from Malvern Instruments. Such instruments are set to produce a volume plot and a lens is selected in accordance with the maker's instructions to accommodate the expected particle size distribution, (or various lenses can be tested until the best lens is identified). Measurements are made by methods known in the art.

[0052] Herein, references to amounts of the deodorant active, including ratios relative thereto, refer to active present as an anhydrous solid, i.e. excluding any water of hydration associated with the active, and also excluding the water-soluble calcium salt and the amino acid present in the composition and / or associated with the active.

[0053] The deodorant active is present in the composition at less than 50%, preferably less than 30%, more preferably less than 25 %, and, in compositions giving especially low marks, less than 20%.

[0054] In order to achieve good to excellent deodorancy, it is also important not to have too little deodorant active present. Hence, the level of the deodorant active is preferably from 5 to 30%, more preferably from 10 to 30% and further preferably from 12 to 25%.

[0055] Compositions according to the present invention have a certain hardness in order for them to be used as sticks or soft solids.

[0056] The “hardness” of stick and soft solid compositions refers to the depth, in millimetres, that a cone penetrates into a test specimen under fixed conditions, as determined in accordance with the procedures of ASTM Method D217-48, incorporated herein by reference, using a Petrotest PNR10 Penetrometer (or equivalent), equipped with an ASTMD2884 plunger (Petrotest Cat. #18-0081 or equivalent, weight =47.5 g) and a 2.5 g aluminium cone, 20° angle with a base diameter of 10 mm, wherein hardness values are reported as an average of 6 replicate measurements.

[0057] Compositions according to the present invention typically have a hardness of less than 30 mm, preferably less than 25 mm and more preferably less than 20 mm.Soft solid compositions according to the present invention typically have a hardness value of from 5 to 25 mm, more particularly from 10 to 20 mm.

[0058] Stick compositions according to the present invention typically have a hardness value of less 20 mm and preferably less than 15 mm. Particularly preferred stick compositions have a hardness of from 7.5 to 12.5 mm.

[0059] The C15-C19 alkane hydrocarbon is present to act as a carrier fluid / oil, either by itself or in combination with other carrier fluid / oil materials. Hence, compositions according to the invention may alternatively be described as comprising a carrier oil comprising a C15-C19 alkane hydrocarbon.

[0060] The C15-C19 alkane hydrocarbon may be present as a single material or it may comprise more than one material of that description.

[0061] The carrier fluid as whole, comprising the C15-C19 alkane hydrocarbon, is a liquid material that is non-miscible with water. It is preferably free from silicone oil. Herein, volatile cyclic silicone oils and volatile silicones should be understood to be silicone oils having a vapour pressure of greater than 1 Pa at 25 degrees centigrade.

[0062] The absence of silicone oil is preferable for many reasons, including environmental benefits. It is preferred that compositions according to the invention are free from all volatile silicone oils and, more preferably, free from all silicone oils. By avoiding silicone oils, the biodegradability of the composition may be increased.

[0063] In preferred embodiments, the C15-C19 alkane hydrocarbon is saturated. In particularly preferred embodiments, it comprises saturated C15-C19 linear, branched and cyclic hydrocarbons. In especially preferred embodiments, it consists of saturated C15-C19 linear, branched and cyclic hydrocarbons, the CAS number is 64742-46-7. Such materials are available from SEPPIC under the tradename Emosmart L19.

[0064] In preferred embodiments, the C15-C19 alkane hydrocarbon comprises from 10 to 35 % by weight of the oils present in the carrier oil, preferably from 15 to 25 % by weight of the oils present in the carrier oil.In preferred embodiments, the C15-C19 alkane hydrocarbon comprises from 10 to 35 % by weight of the deodorant stick composition, preferably from 15 to 25 % by weight of the deodorant stick composition.

[0065] An additional component of the carrier oil is a mineral oil, preferably a light mineral oil. An exemplary light mineral oil has a CAS number 8042-47-5.

[0066] In preferred embodiments, the mineral oil comprises from 10 to 35 % by weight of the oils present in the carrier oil, preferably from 12 to 30 % by weight of the oils present in the carrier oil, preferably from 15 to 25 % by weight of the oils present in the carrier oil.

[0067] In a preferred embodiment the C15-C19 alkane hydrocarbon and mineral oil are employed, preferably a light mineral oil.

[0068] In a preferred embodiment the ratio of C15-C19 alkane hydrocarbon and mineral oil is from 3:1 to 1:3, preferably from 2:1 to 1:2.

[0069] A preferred additional component of the carrier fluid is an ether oil.

[0070] Suitable carrier oils can be selected from 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.

[0071] In preferred embodiments, the ether oil comprises from 10 to 35 % by weight of the oils present in the carrier oil, preferably from 12 to 30 % by weight of the oils present in the carrier oil, preferably from 15 to 25 % by weight of the oils present in the carrier oil.

[0072] In some preferred embodiments, an ester oil is also employed, especially in compositions also comprising an ether oil.

[0073] Further suitable carrier oils, that can also be emollient oils, comprise alkyl or alkyl-aryl ester oils having a boiling point of above 150°C (and a melting point of below 20°C). Such ester oils include oils containing one or two alkyl groups of 12 to 24 carbon atoms length, includingisopropyl myristate, isopropyl palmitate and myristyl palmitate. Other non-volatile ester oils include alkyl or aryl benzoates such C12-15 alkyl benzoate, for example Finsolv TN™ or Finsolv Sun™.

[0074] In preferred embodiments, the ester oil comprises from 5 to 35 % by weight of the oils present in the carrier oil, preferably from 8 to 25 % by weight of the oils present in the carrier oil, preferably from 10 to 20 % by weight of the oils present in the carrier oil.

[0075] Another type of ester oil used in certain preferred embodiments are triglycerides of unsaturated fatty acids. These oils are typically natural oils and are biodegradable. Herein, a “triglyceride of an unsaturated fatty acid” should be understood to mean a triglyceride wherein at least 50% of the fatty acids contain at least one double-bond. Such triglycerides are typically mixtures of glycerol esters with different fatty acids. A preferred oil of this type is Helianthus Annuus seed oil, otherwise known as sunflower seed oil.

[0076] A further essential component of compositions of the invention is a thickening agent, sometimes alternatively referred to as a gelling agent or gellant. Such agents increase the viscosity of or solidify the carrier oil in which the particulate antiperspirant active is typically suspended.

[0077] The thickening agent may be selected from any of those known in the art. Often, the thickening agent includes a wax. Waxes typically are considered to melt at above 40°C and particularly between 55 and 95°C. Waxes can include ester waxes, including C12 to C24 linear fatty alcohols, waxes obtained from animals or plants, often after hydrogenation, silicone elastomers and silicone waxes. The thickening agent can comprise a mixture of particulate thickening agents, a mixture of waxes or a mixture of both types of material.

[0078] The thickening agents used in compositions according to the invention, and especially stick compositions according to the invention, are preferably selected from fibre-forming non-polymeric gelling agents and waxes, optionally supplemented by particulate silica and / or an oilsoluble polymeric thickening agent.

[0079] Waxes employed herein as thickening agents are often selected from hydrocarbons, linear fatty alcohols, silicone polymers, esters of fatty acids or mixtures containing such compounds along with a minority (less than 50% w / w and often less than 20% w / w) of other compounds.Naturally occurring waxes are often mixtures of compounds which include a substantial proportion of fatty esters.

[0080] Examples of hydrocarbon waxes include paraffin wax, ozakerite, microcrystalline wax and polyethylene wax, the last named desirably having an average molecular weight of from 300 to 600 and advantageously from 350 to 525.

[0081] Linear fatty alcohols commonly contain from 14 to 40 carbon atoms and often from 16 to 24. Preferred thickening agents of this class are stearyl alcohol and behenyl alcohol, with stearyl alcohol being especially preferred.

[0082] In preferred embodiments, the stearyl alcohol comprises from 10 to 35 % by weight of the oils present in the carrier oil, preferably from 12 to 30 % by weight of the oils present in the carrier oil, preferably from 15 to 25 % by weight of the oils present in the carrier oil.

[0083] Examples of ester waxes include esters of C16-C22 fatty acids with glycerol or ethylene glycol, which can be isolated from natural products or more conveniently synthesised from the respective aliphatic alcohol and carboxylic acid.

[0084] Examples of natural waxes include beeswax, wool wax and spermaceti wax of animal origin, and caster wax, jojoba wax, carnauba wax and candelilla wax which are of vegetable origin. Montan wax, which is an example of mineral wax, includes non-glyceride esters of carboxylic acids, hydrocarbons and other constituents.

[0085] Fibre-forming thickening agents are dissolved in the carrier oil at elevated temperature and on cooling precipitate out to form a network of very thin strands that structure, i.e. thicken, the carrier oil. One particularly effective category comprises N-acyl aminoacid amides and in particular linear and branched N-acyl glutamic acid dialkylamides, such as in particular N-lauroyl glutamic acid di n-butylamide and N-ethylhexanoyl glutamic acid di n-butylamide and especially mixtures thereof. Such amido gellants can be employed in anhydrous compositions according to the present invention, if desired, with 12-hydroxystearic acid.

[0086] Other amido SMGAs include 12-hydroxystearic acid amides, and amide derivatives of di and tribasic carboxylic acids as set forth in WO 98 / 27954, including notably alkyl N , N ’dialkyl succinamides.Further suitable amido-containing thickening agents are described in US6410003, US7332153, US6410001, US6321841, and US6248312.

[0087] The thickening agent is typically employed in the composition at a concentration of from 1.5 to 30%. When a fibre-forming thickening agent is employed, its concentration is typically in the range of from 1.5 to 15%. When a wax is employed, its concentration is usually selected in the range of from 0.1 to 10%, and particularly from 0.5 to 6% w / w.

[0088] Some highly desirable compositions comprise in combination a first thickening agent with a second thickening agent.

[0089] One category of oil-soluble polymer thickening agent which has been found suitable is a polysaccharide esterified with a mono-carboxylic acid containing at least 12 carbon atoms, and preferably a dextrin fatty acid ester such as dextrin palmitate or dextrin stearate. Commercial products are available under the trade mark Rheopearl.

[0090] A second category of polymer thickening agent comprises polyamides for example those discussed in US 5500209 or US 6353076.

[0091] A third category of thickening agent comprises block copolymers of styrene with ethylene propylene and / or butylene available under the trade name KRATON, and particularly styrene ethylene / butylene styrene linear block copolymers. A related category of thickening polymer comprises polymers of alpha methylstyrene and styrene, such as those under the trade name KRISTALEX, eg KRISTALEX F85 having a mean molecular weight of approximately 1200. Yet another thickening polymer comprises alkyl substituted galactomannan available under the trade name N-HANCE AG.

[0092] A still further class of thickening polymers co-polymers of vinyl pyrrolidone with polyethylene containing at least 25 methylene units, such as triacontanyl polyvinylpyrrolidone, under the trade name Antaron WP-660.

[0093] Such thickening polymer is often employed in a weight ratio to the oil blend that is selected in the range of from 1 :30 to 1 :5, taking into account the hardness of the soft solid that is desired,the inherent ability of the chosen polymer to increase viscosity and the presence or otherwise of an additional thickening agent.

[0094] A thickening agent especially well suited to forming or contributing to the formation of a soft solid composition comprises particulate silica and especially fumed silica. It is desirable to include at least 2% and especially at least 2.5% by weight of the silica in the composition, such as in the range of up to 10% by weight.

[0095] Other components that may be included in compositions according to the invention including those described in the following paragraphs.

[0096] Wash-off agents may be included, often in an amount of up to 10%, to assist in the removal of the formulation from skin or clothing. Such wash-off agents are typically non-ionic surfactants such as esters or ethers containing a Cs to C22 alkyl moiety and a hydrophilic moiety comprising a polyoxyalkylene group (POE or POP).

[0097] Skin feel improvers (e.g. talc or finely divided high molecular weight polyethylene), may be included, typically in an amount from 1 up to 10%.

[0098] Skin moisturisers, such as glycerol or polyethylene glycol (e.g. mol. wt. 200 to 600) may be included, typically in an amount of up to 5%.

[0099] Skin benefit agents, such as allantoin or lipids, may be included, typically in an amount of up to 5%.

[0100] A highly preferred optional component is a preservative, such as ethyl or methyl parabens or BHT (butyl hydroxy toluene), typically in an amount of from 0.01 to 0.1%.

[0101] Herein, the terms “oil” and signifies a water-insoluble organic material that is liquid at 20°C. Any material having a solubility of less than 0.1g / 100g at 20°C is considered to be insoluble.

[0102] Compositions of the invention comprise a fragrance comprising one or more components selected from linalool, limonene, dihydromyrcenol, benzyl acetate, citronellol, linalyl acetate, alpha-methyl ionone, and hexyl cinnamal. These fragrance components are generally described as fresh, floral and / or fruity and give desirably odours on topical application.Unfortunately, whilst the odour of the fragrance components mentioned above is desirable, they can have a very high impact on initial application, particularly from stick compositions. The high levels present on initial application can have an over-powering effect, not liked by some consumers and potentially detracting from the perception of other fragrance components present. This problem is addressed by the present invention via the use of a suitable nonsilicone carrier oil / fluid.

[0103] The benefit in moving from silicone oil carrier fluids to non-silicone carrier fluids in deodorant stick compositions is mentioned above. We have found that this can lead to a desirable change in initial fragrance levels of the fresh, floral and / or fruity fragrance components mentioned above. Such a change can allow either a decrease or increase in fragrance levels of different components, allowing the initial fragrance levels of the fragrance components to be varied depending on the desired initial fragrance profile and experience to the user.

[0104] In one embodiment of the invention, the fragrance component employed is one or more selected from linalool, limonene, dihydromyrcenol, benzyl acetate, citronellol, linalyl acetate, and alpha-methyl ionone.

[0105] In a further embodiment of the invention, the fragrance component employed is one or more selected from linalool, dihydromyrcenol, benzyl acetate, citronellol, linalyl acetate, alpha-methyl ionone, and hexyl cinnamal.

[0106] In a further embodiment of the invention, the fragrance component employed is one or more selected from linalool, limonene, linalyl acetate, alpha-methyl ionone, and hexyl cinnamal.

[0107] In a further embodiment of the invention, the fragrance component employed is one or more selected from linalyl acetate, alpha-methyl ionone, and hexyl cinnamal.

[0108] The amount of fragrance in the composition is commonly up to 3%, advantageously is at least 0.5% and particularly from 0.8% to 2%.

[0109] The total amount of the required fragrance components, namely linalool, limonene, dihydromyrcenol, benzyl acetate, citronellol, linalyl acetate, alpha-methyl ionone, and hexyl cinnamal, and preferred selections from this list, can vary markedly. In some embodiments itmay be 5 ppm or greater, 10 ppm or greater or 50 ppm or greater. In other embodiments it may be up to 1%, 2% or 4%. Preferred ranges for incorporation of the indicated fragrance components may come from combining any of the minimum amounts indicated above with any of the maximum amounts; for example, from 10 ppm to 4% by weight.

[0110] Other optional ingredients can include sensory modifiers, such as talc or finely divided polyethylene, such as in an amount of up to 3% by weight of the composition; colorants, by way of non-limiting example in a proportion of up to 0.5% of the base composition; skin cooling agents such as menthol often selected in an amount of up 0.5%, particularly up to 0.2% of the base composition, and wash-off agents such as non-ionic surfactants, and particularly polyethoxylated fatty alcohols or acids, for example in an amount of up to about 3% of the base composition.

[0111] The method of manufacture involves multiple steps; in particular, steps involved in the manufacture of the deodorant active and steps involved in its formulation.

[0112] In preferred embodiments, the ASCH is first activated by heating it in aqueous solution with a water-soluble calcium salt and an amino acid. Calcium chloride and glycine may be used as the water-soluble calcium salt and the amino acid in this step. The aqueous mixture is typically heated to an extent to achieve a Band III content of at least 55%. The aqueous mixture may be heated to a temperature of greater 70°C for greater than 3 hours.

[0113] Following the activation step described immediately above, the aqueous solution is typically spray dried.

[0114] Following the spray drying, the deodorant active is milled, preferably to give a mean particle size (D50) of from 6 to 25 microns, and more preferably from 7 to 15 microns.

[0115] The milled deodorant active is formulated into the stick composition by first mixing it with the carrier oil which comprises the C15-C19 alkane hydrocarbon. This is preferably done using a high shear mixer.

[0116] Fragrance, comprising one or more components selected from linalool, benzyl acetate, citronellol, linalyl acetate, and alpha-methyl ionone, is then added.A preferred method of manufacture combines some or all of the processes described in the above paragraphs.

[0117] Examples

[0118] In the following examples, a model fragrance was employed which was composed of equal weights of the fragrance components indicated in Table 1. Most of the components had a distinct odour and these are also described in Table 1; however, triethyl citrate and isopropyl myristate were added merely as diluent oils. The model fragrance was well-balanced, comprising both fresh, floral components in addition to sweeter, more spicy and more woody components.

[0119] The model fragrance described above was introduced into the stick compositions indicated in Table 2 at a level of 1% by adding 1 parts of the fragrance to 99 parts of each of the base compositions. The stick compositions were prepared by methods known in the art. An exemplary method of preparing antiperspirant stick products is described in: ‘Chemistry and Technology of the Cosmetics and Toiletries Industry’1'6Ed., Blackie Academic & Professional (1996); section 10.7.2.Table 1: Fragrance components investigated

[0120]

[0121] Table 2: Stick Compositions

[0122]

[0123] * Activated aluminium sesquichlorohydate: aluminium sesquichlorohydate activated by heating in aqueous solution with calcium chloride and glycine, followed by spray drying.

[0124] ** A blend of C15 to C19 alkanes, Emosmart L19 (Supplied by SEPPIC).

[0125] The fragranced stick compositions were tested in the following manner. Approximately 0.07 g of each was applied evenly to fragrance blotters, exact weights of application being recorded. The blotters were loosely rolled up and placed in headspace vials, which were then sealed. 3 replicate vials were prepared for each stick tested.

[0126] Immediately after sample preparation, the headspace above the blotters was analysed by GCMS. The peak area for most of the fragrance components was recorded for each of the triplicate sample injections; however, the peaks for Farnesol and benzyl salicylate could not be identified, so these were excluded from the analysis.

[0127] The results for Comparative Example A (labelled D5) and Example 1 (labelled L19) are presented in Figure 1. The bars in the chart indicate the mean headspace values (averageGCMS peak areas) for each of the fragrance components indicated, normalized against the exact weights of each sample applied.

[0128] In changing the carrier oil from D5 (Comparative Example A) to C15 to C19 alkane (Example 1), the initial level of many of the fragrance component was reduced, as desired. This reduction in initial fragrance impact was significant at the 95% confidence level of greater for the following fragrance components:

[0129] (i) Limonene;

[0130] (ii) DHM;

[0131] (iii) Linalool;

[0132] (iv) benzyl acetate;

[0133] (v) methyl 2-octyynoate;

[0134] (vi) Citronellol;

[0135] (vii) Citral;

[0136] (viii) linalyl acetate;

[0137] (ix) Geraniol;

[0138] (x) Eugenol;

[0139] (xi) AMI; and

[0140] (xii) amyl cinnamal.

[0141] Of the above fragrance components, methyl 2-octyynoate, citral, geraniol, eugenol and amyl cinnamal are not fresh, floral and / or fruity fragrance components, with which the present invention is particularly concerned.

Claims

Claims1. A deodorant stick composition comprising (i) an activated aluminium sesquichlorohydrate salt comprising aluminium sesquichlorohydrate of formula AI2OH4.4CI1.6 to AI2OH4.9CI1.1, a water-soluble calcium salt and an amino acid; (ii) a C15-C19 alkane hydrocarbon and (iii) a fragrance comprising one or more components selected from linalool, limonene, dihydromyrcenol, benzyl acetate, citronellol, linalyl acetate, alpha-methyl ionone, and hexyl cinnamal.

2. A composition according to claim 1, wherein the fragrance comprises one or more components selected from linalool, limonene, dihydromyrcenol, benzyl acetate, citronellol, linalyl acetate, and alpha-methyl ionone.

3. A composition according to claim 2, wherein the fragrance comprises one or more components selected from linalool, dihydromyrcenol, benzyl acetate, citronellol, linalyl acetate, and alpha-methyl ionone.

4. A composition according to claim 1, wherein the fragrance comprises one or more components selected from linalool, limonene, linalyl acetate, alpha-methyl ionone, and hexyl cinnamal.

5. A composition according to claim 4, wherein the fragrance comprises one or more components selected from linalyl acetate, alpha-methyl ionone, and hexyl cinnamal.

6. A composition according to any one of the preceding claims, wherein the C15-C19 alkane hydrocarbon comprises linear and branched C15-C19 alkane hydrocarbons.

7. A composition according to any one of the preceding claims, wherein the composition is free from silicone oil.

8. A composition according to any one of the preceding claims comprising mineral oil.

9. A composition according to gas any one of the preceding claims comprising an ether oil.

10. A composition according to any one of the preceding claims comprising an ester oil.

11. A composition according to any one of the preceding claims comprising a thickening agent.

12. A composition according to any one of the preceding claims comprising a wash-off agent.

13. A method of manufacture of a composition according to one any of claims 1 to 12.

14. A non-therapeutic method of achieving improved odour perception on surface of the human body comprising the topical application of a deodorant stick composition according to any one of claims 1 to 12.

15. The non-therapeutic use of a deodorant stick composition according to any one of claims 1 to 12 to improve odour perception on the surface of the human body following topical application of said deodorant stick composition.

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