Deodorant aerosol composition comprising an activated aluminium sesquichlorohydrate

Abstract

A deodorant aerosol composition comprising an activated aluminium sesquichlorohydrate, a C14-C18 branched-chain hydrocarbon and a fragrance comprising one or more components selected from limonene, dihydromyrcenol, linalool, benzyl acetate, citronellol, linalyl acetate, alpha-methyl ionone, gamma undecalactone, methyl dihydrojasmonate and hexyl cinnamal.

Description

[0001] DEODORANT AEROSOL COMPOSITION

[0002] Field of Invention

[0003] The present invention relates to deodorant aerosol 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 aerosol 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 aerosol 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 aerosol 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 aerosol composition that also delivers a reduced perspiration benefit. In a first aspect of the invention there is provided a deodorant aerosol composition comprising an activated aluminium sesquichlorohydrate of formula AI2OH4.4CI1.6 to AI2OH4.9CI1.1, a C14-C18 branched-chain hydrocarbon and a fragrance comprising one or more components selected from limonene, dihydromyrcenol, linalool, benzyl acetate, citronellol, linalyl acetate, alpha-methyl ionone, gamma undecalactone, methyl dihydrojasmonate and hexyl cinnamate.

[0012] In a second aspect of the invention there is provided a method of manufacture of an anhydrous AP aerosol composition according to the first aspect of the invention.

[0013] 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 aerosol composition according to the first aspect of the invention.

[0014] In a fourth aspect of the invention there is provided the non-therapeutic use of a deodorant aerosol composition according to the first aspect of the invention to improve odour perception on surface of the human body following topical application thereof.

[0015] Detailed Description

[0016] 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.

[0017] Herein, an aerosol composition is a liquid composition capable of forming an aerosol when expelled through an orifice suitable for producing an aerosol.

[0018] Herein, the “base composition” is the full composition excluding any propellant that may be present therein, unless indicated otherwise.

[0019] Herein, topical application refers to application to the skin of the human body, in particular to the underarm regions of the human body. Herein, deodorant actives are materials that reduce malodour on the skin of the human body, typically following topical application.

[0020] Herein, the C14-C18 branched-chain hydrocarbon is a material comprising solely carbon and hydrogen atoms and having from 14 to 18 carbon atoms arranged such that there is at least one branch, i.e. at least one tertiary carbon atom.

[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.

[0023] Herein, references to an amount of a material or materials refer to the total amount of material(s) of the type indicated.

[0024] Herein, references to an amount of a material are with reference to the total composition of which it is a part, unless otherwise indicated.

[0025] Herein, “application” and “applied” relate to application to the skin of the human body, in particular the underarm regions, unless the context dictates otherwise.

[0026] 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.

[0027] 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.

[0028] Herein, “ambient conditions” refer to 20°C and 1 atmosphere pressure, unless otherwise indicated. 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 aerosol compositions are typically sprayed 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 C14-C18 branched-chain 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. 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 to reduce perspiration.

[0035] 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.

[0036] Herein, the term “activated” should be understood to mean increased in efficacy. The activated ASCH salts of the present invention are activated by the presence of the water- soluble calcium salt and amino acid.

[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.

[0039] 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. 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.

[0045] 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. 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 30%, preferably less than 25% and, in compositions giving especially low marks, less than 20%, all figures excluding any propellant that may be present therein.

[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%, all figures excluding any propellant that may be present therein.

[0055] The C14-C18 branched-chain hydrocarbon is present to act as a carrier fluid / oil, either by itself or in combination with other carrier fluid materials. Hence, compositions according to the invention may alternatively be described as comprising a carrier oil comprising a C14- C18 branched-chain hydrocarbon.

[0056] The C14-C18 branched-chain hydrocarbon may be present as a single material or it may comprise more than one material of that description.

[0057] The carrier fluid as whole, comprising the C14-C18 branched-chain hydrocarbon, is a liquid material that is non-miscible with water. It is preferably free from silicone oil. The absence of silicone oil is preferable for many reasons, including cost and environmental benefits. By avoiding silicone oils, the biodegradability of the composition may be increased.

[0058] In preferred embodiments, the C14-C18 branched chain hydrocarbon is saturated. In particularly preferred embodiments, the C14-C18 branched chain hydrocarbon is saturated and acyclic.

[0059] In certain preferred embodiments, the carrier fluid is free from branched chain hydrocarbons that are shorter than 14 carbon atoms or longer than 18 carbon atoms; i.e. , the composition is preferably free from branched chain hydrocarbons that are shorter than 14 carbon atoms or longer than 18 carbon atoms.

[0060] In particularly preferred embodiments, the C14-C18 branched chain hydrocarbon is a saturated and acyclic C16 alkane. In especially preferred embodiments it is isohexadecane (IHD).

[0061] In preferred embodiments, the C14-C18 branched chain hydrocarbon is the predominant oil in the carrier oil. By “predominant”, it is meant that this oil is present in a higher amount than any other single oil.

[0062] In preferred embodiments, the C14-C18 branched chain hydrocarbon comprises greater than 35% by weight of the oils present in the carrier oil.

[0063] A preferred additional component of the carrier fluid is an ether oil.

[0064] In some preferred embodiments, an ester oil is also employed, especially in compositions also comprising an ether oil.

[0065] A 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.

[0066] The total amount of C14-C18 branched chain hydrocarbon in the composition, excluding any volatile propellant present therein, is preferably from 15 to 75%, more preferably from 20 to 70% and most preferably from 25 to 60%.

[0067] Compositions of the invention comprise a fragrance comprising one or more components selected from limonene, dihydromyrcenol, linalool, benzyl acetate, citronellol, linalyl acetate, alpha-methyl ionone, gamma undecalactone, methyl dihydrojasmonate and hexyl cinnamal. These fragrance components are generally described as fresh, floral and / or fruity and give desirably odours on topical application.

[0068] Unfortunately, whilst the odour of the fragrance components mentioned above is desirable, they can have a very high impact on initial application, particularly from aerosol 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 non-silicone carrier oil / fluid.

[0069] The benefit in moving from silicone oil carrier fluids to non-silicone carrier fluids in deodorant aerosol compositions is mentioned above. We have found that this can lead to a desirable decrease in initial fragrance levels of the fresh, floral and / or fruity fragrance components mentioned above.

[0070] In one embodiment of the invention, the fragrance component employed is one or more selected from dihydromyrcenol, linalool, benzyl acetate, citronellol, linalyl acetate, alphamethyl ionone, gamma undecalactone, methyl dihydrojasmonate and hexyl cinnamal Limonene is excluded from this list because the initial impact of this fragrance component can also be decreased on moving from carrier fluid comprising D5 to a carrier fluid comprising alternative branched chain alkanes, such as IDD (vide infra). In a further embodiment of the invention, the fragrance component employed is one or more selected from limonene, dihydromyrcenol, linalool, benzyl acetate, citronellol, linalyl acetate, and alpha-methyl ionone. The initial impact of these fragrance components were each decreased by an amount significant at the 95% on moving from a silicone oil to a C14-C18 branched-chain hydrocarbon in the carrier oil (vide infra).

[0071] In a further embodiment of the invention, the fragrance component employed is one or more selected from dihydromyrcenol, linalool, benzyl acetate, citronellol, linalyl acetate, and alpha-methyl ionone. This list combines the restrictions described in the above two paragraphs.

[0072] In a further embodiment of the invention, the fragrance component employed is one or more selected from linalool, benzyl acetate, citronellol, linalyl acetate, and alpha-methyl ionone. The initial impact of these fragrance components was decreased by the greatest amount on moving from a silicone oil in the carrier to a C14-C18 branched-chain hydrocarbon in the carrier oil in our studies (vide infra).

[0073] In a further embodiment of the invention, the fragrance component employed is one or more selected from one or more components selected from benzyl acetate, citronellol, linalyl acetate, and alpha-methyl ionone.

[0074] The decrease in initial fragrance levels of dihydromyrcenol, linalool, benzyl acetate, citronellol, linalyl acetate, and alpha-methyl ionone has been found to be particularly good relatively to that of alternative branched-chain hydrocarbons, such as isododecane (IDD) (vide infra).

[0075] The decrease in initial fragrance levels of linalool, benzyl acetate, citronellol, linalyl acetate, and alpha-methyl ionone has been found to be particularly high. Of these fragrance components, benzyl acetate, citronellol, linalyl acetate, and alpha-methyl ionone are preferred because the initial fragrance level of those fragrance components were decrease the most on moving from a silicone carrier fluid to a C14-C18 branched- chain hydrocarbon. The amount of fragrance in the composition, excluding any propellant that may be present therein, is preferably up to 20%, advantageously is at least 4% and particularly from 6% to 15%.

[0076] The total amount of the required fragrance components, namely limonene, dihydromyrcenol, linalool, benzyl acetate, citronellol, linalyl acetate, alpha-methyl ionone, gamma undecalactone, methyl dihydrojasmonate and hexyl cinnamal, and specified selections from this list, can vary markedly. In some embodiments it may 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.

[0077] A propellant is not an essential component of compositions of the invention because an aerosol may be created purely by mechanical means, such as pump spray or squeeze spray mechanism. However, a propellant is a preferred feature of compositions of the invention.

[0078] When employed, the propellant may be a liquified gas, a pressurised gas such as nitrogen or any combination thereof.

[0079] It is preferred that compositions of the invention comprise a propellant that is a liquified gas.

[0080] Suitable liquified gases suitable for use as propellants used with the present invention include propane, butane, isobutane, DME, and hydrofluorocarbons, such as difluoroethane, otherwise known by the INCI name of HFC152a. Preferred propellants are mixtures of propane, butane and isobutane or mixtures of one or more hydrofluorocarbons (difluoroethane being preferred) and C3 to C4 alkanes.

[0081] When a propellant is employed, it is preferably used at a level of from 50%, more preferably from 65% and most preferably at from 80% of the total composition. Suitable ranges of inclusion of propellant are from 50 to 95%, more preferably from 65 to 95%, and most preferably from 80 to 95% of the total composition. Such preferred minimum amounts and ranges can assist with the reduced white marks benefit of the present invention.

[0082] A suspending agent is a highly preferred component of compositions of the invention, 'active in the composition. 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 20 Elementis).

[0083] The suspending agent is typically employed at from 0.1 to 1.5% by weight of the total composition.

[0084] When a suspending agent is present, in particular a clay-based suspending agent, it is preferred that an activator for the suspending agent is also present. The activator serves to improve the performance of the suspending agent. Preferred activators are triethyl citrate and propylene carbonate. Propylene carbonate is especially preferred.

[0085] The activator is preferably used at a level of from 0.01 to 0.25% of the total composition.

[0086] 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 base 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 nonionic surfactants, and particularly polyethoxylated fatty alcohols or acids, for example in an amount of up to about 3% of the base composition.

[0087] The method of manufacture involves multiple steps; in particular, steps involved in the manufacture of the deodorant active and steps involved in its formulation.

[0088] 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.

[0089] Following the activation step described immediately above, the aqueous solution is typically spray dried. This is preferably done using rotary atomisation.

[0090] 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.

[0091] The milled deodorant active is formulated into the aerosol composition by first mixing it with the carrier oil which comprises the C14-C18 branched-chain hydrocarbon and, typically, a suspending agent such as a bentonite clay. This is preferably done using a high shear mixer. An “activator” for the suspending agent is also generally added. Propylene carbonate is a preferred activator.

[0092] Fragrance, comprising one or more components selected from linalool, benzyl acetate, citronellol, linalyl acetate, and alpha-methyl ionone, is then added. Preferably, this is done immediately before the base is gassed with the propellant. The base (plus or minus fragrance) may often be stored for several days before the propellant is added. It is desired that the base has sufficient viscosity stability to be still usable after storage for up to 7 days at ambient temperature

[0093] A preferred method of manufacture combines some or all of the processes described in the above paragraphs.

[0094] A particularly preferred method of manufacture involves the following steps:

[0095] (i) activated ASCH by heating it in aqueous solution with a water-soluble calcium salt and an amino acid;

[0096] (ii) the aqueous solution resulting from step (ii) is spray dried;

[0097] (iii) the powder resulting from step (ii) is milled; (iv) the milled powder from step (iii) is mixed with a carrier oil comprising a C14- C18 branched-chain hydrocarbon;

[0098] (v) fragrance is added, the fragrance comprising one or more components selected from linalool, benzyl acetate, citronellol, linalyl acetate, and alphamethyl ionone; and

[0099] (vi) the base composition resulting from step (v) is gassed with a volatile propellant.

[0100] Examples

[0101] 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.

[0102] The model fragrance described in Table 1 was introduced into the aerosol base compositions indicated in Table 2 at a level of 7% by adding 7 parts of the fragrance to 93 parts of each of the base compositions. The aerosol base compositions were prepared by methods known in the art. When gassed with propellant at a base to propellant ratio of 13: 87, the resulting aerosol compositions comprised approximately 1% of the model fragrance.

[0103] Table 1: Fragrance components investigated

[0104] Table 2: Aerosol Base Compositions

[0105] * activated aluminium sesquichlorohydate: aluminium sesquichlorohydate activated by heating in aqueous solution with calcium chloride and glycine, followed by spray drying. The fragranced aerosol base compositions were tested in the following manner. Approximately 0.1 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 aerosol base tested.

[0106] Immediately after sample preparation, the headspace above the blotters was analysed by GCMS. The peak area for each fragrance component was recorded for each of the triplicate sample injections. The results for Comparative Example A and Example 1 are presented in Table 3, normalized against the exact weights of each sample applied.

[0107] In changing the carrier oil from D5 (Comparative Example A) to IHD (Example 1), the initial level of each fragrance component was reduced; however, it was reduced more for some fragrance components more than others. Details of the differences in these reductions are given in the two right hand columns of Table 3. It may be seen that whilst the initial fragrance levels of limonene and dihydromyrcenol was reduced by only 33.7% and 29%, the initial fragrance levels of benzyl acetate, citronellol, linalyl acetate and alpha-methyl ionone was reduced by from 41.4% to 44.9%.

[0108] Table 3: Results for IHD vs. D5

[0109] The reduction in the initial fragrance levels of limonene, dihydromyrcenol, linalool, benzyl acetate, citronellol, linalyl acetate, and alpha-methyl ionone was significant at the 95% level. This was not the case for the fragrance components GLIDL, MDHLI and hexyl cinnamyl. The fragrance component Iso E Super, whilst included in the model fragrance tested, is not a fragrance component having fresh, fruity and / or floral odour profile as desired in the present invention. The mean headspace numbers given in Table 3 are average GCMS peak areas for each of the fragrance components indicated, normalising for slight differences in the 0.1 g dosage applied, as mentioned above.

[0110] In a further study, the above experiment was repeated using a different branched-chain hydrocarbon, IDD, instead of I HD. The results are present in Table 4. Again, it was found that on changing the carrier oil from D5 to branched-chain alkane (IDD, Comparative Example B), the initial level of each fragrance component was reduced. Focusing on the fragrance components dihydromyrcenol, linalool, benzyl acetate, citronellol, linalyl acetate and alpha-methyl ionone, it may be seen that the initial fragrance reduction was from 3.4% to 17.5%. This is much less than the reduction achieved on moving from D5 carrier oil to IHD (cf. Table 3 results). This was not the case for limonene, were the initial fragrance impact on moving from D5 to IHD or IDD was similar.

[0111] Table 4: Results for IDD vs. D5

Claims

CLAIMS1 . A deodorant aerosol 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 C14-C18 branched-chain hydrocarbon and (iii) a fragrance comprising one or more components selected from limonene, dihydromyrcenol, linalool, benzyl acetate, citronellol, linalyl acetate, alpha-methyl ionone, gamma undecalactone, methyl dihydrojasmonate and hexyl cinnamal.

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

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

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

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

6. A composition according to claim 5, wherein the fragrance comprises one or more components selected from benzyl acetate, citronellol, linalyl acetate, and alphamethyl ionone.

7. A composition according to any one of the preceding claims, wherein the C14-C18 branched-chain hydrocarbon is a saturated C16 branched-chain hydrocarbon.

8. A composition according to claim 7, wherein the saturated C16 branched-chain hydrocarbon is isohexadecane.

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

10. A composition according to any one of the preceding claims comprising a propellant.

11. A composition according to claim 8, wherein the propellant is a liquified gas.

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

13. A composition according to any one of the preceding claims comprising a suspending agent.

14. A non-therapeutic method of achieving improved odour perception on surface of the human body comprising the topical application of a deodorant aerosol composition according to any one of claims 1 to 13.

15. The non-therapeutic use of a deodorant aerosol composition according to any one of claims 1 to 13 to improve odour perception on the surface of the human body following topical application of said deodorant aerosol composition.

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