FORM - 2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See Section 10 and Rule 13)
ANTIPRESPIRANT COMPOSITION AND PRODUCT
HINDUSTAN UNILEVER LIMITED, a company incorporated under
The Indian Companies Act, 1913 and having its registered office
at 165/166, Back bay Reclamation, Mumbai -400 020, Maharashtra, India
The following specification particularly describes the invention and the manner in which it is to be performed

ANTIPERSPIRANT COMPOSITION AND PRODUCT
The present invention relates to an antiperspirant composition and a product containing said composition, and in particular said composition in the form of a dispersion in a sealed sachet.
Brief Summary of the Present Invention
In order to counteract localised sweating, for example in the underarm, it is now common practice in many parts of the world to apply topically to skin a composition containing an active antiperspirant. One class of effective antiperspirants comprises water-soluble astringent antiperspirant salts. Such materials can be employed either as solids in anhydrous compositions, or in solution, such as in water or an aqueous mixture with water-miscible materials such as low weight aliphatic alcohols. Although the solution may be applied as such, an alternative class of composition which has gained favour with many consumers comprises a two phase system comprising the solution of the antiperspirant active with a water-immiscible phase.
Antiperspirant compositions can be applied topically from a wide variety of applicators, sometimes alternatively called dispensers, and the physical nature of ingredients of the composition likewise varies to enable them to be dispensed from such applicators. Thus, the physical nature varies from relatively thin liquids that are sprayed through a sprayhead to solid bars that are lifted through a wide aperture of a dispensing barrel. One particular type of

dispenser comprises a sachet, typically made from a thermoplastic polymeric material, including in particular sachets disclosed in WO2004/112739 to Unilever and Hindustan Lever. Cream compositions for employment in such sachets are disclosed in said 739 publication. Such sachets are heat sealed in order to prevent their contents from being discharged during transportation and storage prior to use and additionally they are more common for antiperspirant products in tropical countries where the ambient temperature during transportation and/or storage can exceed 50°C. The sachets are squeezed to discharge their contents through an aperture cut or torn typically at the edge of the sachet and this places constraints on the physical nature of the dispensed composition. If the composition is too runny, it will be squirted out of the sachet, maybe even when the dispensing aperture is made, and this is not only wasteful, but also disliked by thrifty consumers.
Alternatively, the sachets may also be fitted with a tubular nozzle to enable the contents to be discharged readily onto an applicator surface. The tubular nozzle can be capped easily, e.g. with a screw threaded cap, so that the sachet can be hygienically sealed after every usage. This makes such a sachet (sometimes called a big nose pack) convenient to carry in a purse or pocket for application out of the house, for example while travelling. The manufacturing process of the big nose packs involves thermally fusing the sachet to the tubular nozzle at a temperature of 180-250°C so that the emulsion experiences a thermal shock, albeit for a microsecond. Thermal shock can induce instability, which manifests itself as phase separation, which may occur either

instantaneously or subsequently during transportation or storage.
Two phase compositions, which herein can alternatively be referred to as dispersions, are convenient, forms of composition for incorporation in sachets, because they can be formulated to provide a cream consistency, suitable for controlled discharge from the sachet. However, it has been found that aqueous antiperspirant dispersions of a hydrophobic phase exhibit a tendency to become runny when exposed to elevated temperatures during storage or transportation. This renders them less suitable, messy and liable to be rejected by the consumers. Likewise, it would be desirable for such compositions to be able to resist the localised elevated temperatures encountered during heat sealing of the sachets.
Stick compositions, which the skilled person recognises as adopting the form of a self-supporting non-flowing bar, are described in publications in the name of Henkel (or their inventors), namely WO2006/119981, WP2006/136330 and US2006/0029624 and the applications from which they claim priority. Such stick compositions differ from the invention compositions contemplated herein because of their physical form. A stick has different physical characteristics from a cream arising at least in part from employing significantly different proportions of its ingredients from those in a cream, including the relative proportions of the aqueous and oil phase, and by implication the proportions of water, oils and gellant in the compositions. For example, the Henkel disclosures explicitly limit the maximum % of water to below

50% and most Examples employ between 22.9 and 28.9%, whereas the aqueous phase contemplated in the instant invention is a substantially higher proportion. Consequently, the skilled person is unable to translate disclosures concerning stick compositions into the solution of the problems of cream compositions indicated herein.
Many antiperspirant emulsions are described in US5968490 to Helene Curtis Inc, but such compositions are directed to employing a borate cross linker and therefore providing no teaching in relation to compositions which do not require the presence of a borate cross linker.
It is an object of the present invention to create a dispersion of a hydrophobic phase in an aqueous antiperspirant salt solution that is suitable for incorporation in a sachet and overcomes or at least ameliorates one or more of the disadvantages identified above.
According to one aspect of the present invention, there is provided an aqueous antiperspirant composition in the form of a dispersion comprising
an aqueous phase in an amount of from 82 to 91.5% by weight, containing a soluble astringent antiperspirant salt in an amount of from 5 to 30% by weight,
a water-immiscible phase in an amount of from 5 to 14.5% by weight, containing at least 0.5% by weight of an oil and at least 3% by weight of a wax and

at least 3.5% by weight of a mixture of non-ionic emulsifiers comprising at least 1.5% by weight of a low HLB emulsifier having an HLB value of below 7 and at least 1.5% by weight of a complementary emulsifier having an HLB value such that the weight average HLB value of said mixture is at least 10.
Herein, unless expressly mentioned otherwise, % by weight is based on the weight of the entire dispersion. The emulsifiers are deemed to be located at the interface between the aqueous and water-immiscible phases so that their weight is excluded from both phases in calculating the weight of such phases.
By the selection of such ingredients of the composition in such relative amounts in accordance with the instant invention, the thermal and storage stability of such dispersions is improved, as demonstrated by retaining stability in an elevated temperature test for much longer.
In a second aspect of the present invention, there are provided sachets, optionally further attached to a tubular nozzle, containing the dispersion according to the first aspect which are particularly suitable for distribution in tropical climates and/or resisting thermal shock during manufacture of the filled sachets.
A third aspect of the present invention comprises a process for the manufacture of compositions according to the first aspect.

A fourth aspect comprises the manufacture of a product in accordance with the second aspect.
A fifth aspect comprises topical application of a composition according to the first aspect, optionally from a filled sachet according to the second aspect.
A Detailed Description of the Invention, Including Preferred Embodiments
The present invention relates to disper'sions comprising an aqueous phase, a water-immiscible phase and a combination of emulsifiers, the ingredients being so selected in combination that the resultant dispersion is at least comparatively stable at elevated temperatures, such as temperatures arising in tropical climates and alternatively or preferably additionally is resistant to the thermal profile the dispersion is likely to experience during its manufacturing and filling of a sachet and/or a big nose pack.
One factor to which attention has been paid in making the inventive selection is the nature of the mixture of the emulsifiers. For example, it is desirable to consider not only the overall weight of the emulsifiers, but in addition the individual weight of the two components of that mixture, namely the low HLB emulsifier and the complementary emulsifier. Both emulsifiers are present in such amounts as to allow dispersion with improved stability to be made. The total weight of emulsifiers cresent is desirably at least

3.5%, and particularly at least 4%. Commonly, the total weight of emulsifiers is not higher than 8%, and in many desirable dispersions is up to 7%, and particularly is up to 6%. A preferred range is from 4 to 5.5% by weight of the dispersion. The two low and complementary emulsifiers are preferably present in a weight ratio of at least 0.5:1, and often at least 0.7:1. Said weight ration is commonly not higher than 1.25:1 and in many instances not higher than 1.1:1. Excellent results have been obtained employing said weight ratio in the range of at least 0.75:1, including many dispersions in which said weight ratio is at least 0.8:1. In many valued dispersions said weight ratio is advantageously up to 1:1.
It is desirable for the low HLB emulsifier to be present in an amount of at least 1.5% by weight, preferably at least 1.75% by weight and particularly at least 2% by weight. Commonly, the amount of the low HLB emulsifier is up to 4% by weight, and preferably up to 3% by weight. A particularly preferred range is from 2 to 2.5% by weight. The low HLB emulsifier commonly has an HLB value in the range of from 2 to 7, and many preferred low HLB emulsifiers have an HLB value of above 3. Conveniently, very suitable low HLB emulsifiers are available with an HLB value of up to 6, for example in the range of from 4 to 6. Although the description is written in relation to a single low HLB emulsifier, it will be recognised that a mixture of low HLB emulsifiers can be employed having a weight average HLB value in accordance with the limits given above.

The complementary emulsifier can be regarded as an emulsifier, or mixture of emulsifiers having a high HLB value. Commonly, the complementary emulsifier has an HLB value of at least 12 and advantageously at least 14, for example up to 19.5. In some preferred embodiments, the complementary emulsifier is a mixture of at least two emulsifiers, of which one has a high HLB value of from 14 to 17. Likewise, the mixture of emulsifiers' constituting the complementary emulsifier can comprise an emulsifier having a higher HLB value of for example from 17 to 19.5. It is advantageous to employ a complementary emulsifier comprising both a high HLB emulsifier and a higher HLB emulsifier. The weight ratio of such high and higher HLB emulsifiers is preferably at least 1:1 and desirably up to 2:1. A very convenient range is from 1.2:1 to 1.7:1.
The total proportion of complementary emulsifier in the dispersion is desirably at least 2% by weight, and preferably at least 2.2% by weight. Its total proportion is normally not more than 5% by weight, often up to 4% by weight and in many valued embodiments is up to 3% by weight of the dispersion.
It is particularly desirable to select emulsifiers comprising a polyalkylene oxide derivative of an alkyl acid or alcohol containing at least 12 carbon atoms, often from 16 to 20 carbon atoms and particularly polyethylene oxide derivatives. The HLB value of such emulsifiers varies particularly in relation to the number of ethylene oxide units and also in relation to the chain length of the alkyl moiety. Low HLB emulsifiers often contain up to 4 ethylene

oxide units, preferably 2 or 3 and for high HLB emulsifiers,
the number of ethylene oxide units is often at least 10 at
in many instances up to about 30 units. For emulsifiers
with a higher HLB value, the number of polyethylene oxide
units tends to overlap with the number for high HLB
emulsifiers, depending on the hydrophobic moiety, commencing
at about 25 and extending up to about 150 or 200 units. It
is preferred to employ, .in combination a mixture of
i) a polyethylene oxide alkyl ether containing'2 or 3 units
with cetyl or stearyl alcohol
ii) a polyethylene oxide alkyl ether containing 15 to 25
units with cetyl or stearyl alcohol and
iii) a polyethylene oxide alkyl ester containing 70 to 150
units with palmitic or stearic acid
as representative emulsifiers for i) low HLB emulsifier, ii)
high HLB emulsifier and iii) higher HLB emulsifier.
The mixture of low and complementary emulsifiers is selected so as to generate a weight average HLB value of at least 10, preferably at least 10.5 and particularly at least 11. Said average HLB value in the mixture is commonly up to 13 and in many effective dispersions up to 12.5 and particularly up to 12.
An important constituent of a dispersion cream is a solid which can thicken a hydrophobic phase. In the present invention, it is desirable to employ a wax, and particularly one or a mixture of waxes which has a melting point of at least 55°C. Advantageously, the wax is selected having a melting point of up to 90°C and in many instances up to 80°C. In some highly desirable embodiments, the wax has a melting

point of not higher than 70°C. Amongst the classes of waxes which satisfy the criteria above, a favoured wax is a linear aliphatic alcohol, preferably containing at least 14 carbon atoms. Preferred linear aliphatic alcohols contain from 16 to 24 carbon atoms, and especially preferred alcohols are stearyl alcohol, cetyl alcohol or mixture of the two, the mixture often sold as cetearyl alcohol. It will be recognised that named alcohols often contain small fractions of other alcohols that contain 2 or 4 carbon atoms more or fewer than in said named alcohol. Thus, for example, commercially available stearyl alcohol often comprises up to 5% by weight thereof in total of cetyl alcohol, eicosyl alcohol and behenyl alcohol.
The amount of wax in the dispersion is commonly at least 3% by weight, often at least 3.5% and good results have been obtained when at least 4% by weight wax is present. It is often unnecessary to exceed a wax content of 7% by weight, and indeed, excellent results have been obtained without exceeding 6% by weight wax content. A preferred range of wax content is from 4 to 5.5% by weight. The presence of the wax commonly results in the dispersed hydrophobic (water-immiscible) phase forming solid particles at ambient temperature during distribution or storage of the composition, though when the dispersion is formed, at elevated temperatures, that phase is in the form of liquid droplets. The average particle size of the dispersion is under the control of the manufacturer of the dispersion, depending at least in part on the intensity with which the composition is mixed to generate the droplets. In many embodiments, the weight average particle size is below 25

um such as greater than 1 Jm and for example in the range of from 3 to 10 um.
The instant invention enables cream formulations to be produced in the absence of a borate cross-linker (such as the borate cross linker described in US5968490) .
A further constituent of the dispersion is an oil or mixture of oils, commonly present in an amount of at least 1 or sometimes at least 1.25% by weight. The total weight of oil in the dispersion is often not higher than 6%, in many desirable embodiments not higher than 4%. Excellent results have been obtained with an oil content of from 1.3 to 3% by weight.
Herein the term oil includes any water-immiscible material that is liquid at standard one atmospheric pressure at 20°C. Accordingly, the oil or oils herein can. comprise one or more fragrance oils, silicone oils and or ether oils. Advantageously, chosen silicone and ether oils for incorporation in the invention dispersion have a boiling point in excess of 100°C. Amongst the silicone oils that can be contemplated, it is preferable to employ a so-called volatile silicone oil which most conveniently is a cyclomethicone and preferably one containing on average at least 4.75 silicon atoms, such as D5
(cyclopentadimethylsiloxane), optionally containing a minor fraction of D4 and/or D6, or the corresponding cyclo-tetra (D4) or hexadimethylsiloxane (D6) compounds. Alternatively all or part of the cyclic silicone oils can be replaced by an acyclic silicone oil or blend of similar volatility to

the cyclomethicone oils. The weight proportion of volatile
silicone oil, e.g. volatile cyclomethicone oils in the
dispersion is often in the range of from 0.2 to 0.8% by
weight, such as from 0.35 to 0.55% by weight.
The volatile silicone oils or a fraction of them can be replaced by a so-called non-volatile silicone oil, which is commonly an oil in which a fraction of methyl substituents have been replaced by a phenyl, diphenylethyl or a residue of an a methylstyrene dimer. The ratio of volatile to non¬volatile oils (including any non-volatile silicone oil) in the dispersion, is often selected in the range of from 2:3 to 1:6, and in many desirable embodiments is from 1:2 to 1:4.
The ether oil herein is advantageously derived from a polypropylene glycol, and particularly with an aliphatic monohydric alcohol. Preferably the polypropylene moiety contains from 10 to 20 units. Very desirably, the monohydric alcohol moiety contains from 12 to 20 or from 14 to 20 carbons, and advantageously is liner, such as from stearyl or cetyl alcohol. The weight proportion of the ether oil in the dispersion is desirably at least 0.5% and often up to 2%.
Optionally, the water-immiscible phase can comprise a silicone elastomer, by which is meant a cross linked polysiloxane, and particularly can be a non-emulsifying elastomer. Suitably, the crosslinked silicone elastomer can be formed from the hydrosilylation of vinyl silicone fluids by hydrosiloxane. More preferably, the non-emulsifying siloxane elastomer is a dimethicone/vinyldimethicone cross

polymer. The elastomer when present is preferably in an amount of from 0.025% to 0.1% of the dispersion. Expressed on the basis of the water-immiscible phase, the elastomer is often present in a proportion of from 1 to 3% by weight of that phase. Conveniently, the elastomer can be incorporated when already dispersed in a silicone .oil, for example a volatile silicone oil.
The weight proportion of the water-immiscible phase in the invention dispersion is usually in the range of from 5 to 14.5% of the dispersion, and in many desirable formulations is at least 6%. In preferred formulations the weight proportion of said phase is up to 11% and particularly up to 9% of the dispersion.
The weight proportion of the aqueous phase in the invention dispersion is usually in the range of from 82 to 91.5% of the dispersion, and in many desirable formulations is at least 85%. In preferred formulations, the weight proportion of said phase is up to 90% of the dispersion.
Antiperspirant actives for use herein are often selected from astringent active salts, including in particular aluminium salts, zirconium salts and mixed aluminium-zirconium salts, including for each both inorganic salts and organic salts and complexes. Preferred astringent salts include aluminium, zirconium and aluminium-zirconium halides and halohydrate salts, such as chlorohydrates. Many preferred antiperspirant astringent salts are aluminium and/or zirconium chlorohydrates, optionally complexed.

Preferred aluminium salts include aluminium halohydrates
having the general formula AI2(OH)xQy.WH2O in which Q
represents chlorine, bromine or iodine, x is from 2 to 5 and x + y = 6, x and y being either integers or non-integers and w represents a variable amount of hydration, which may be zero. Activated aluminium chlorohydrates such as those described in EP-A-6739 (Unilever NV et al), may be dissolved in the aqueous phase of the instant dispersions.
A range of zirconium salts which can be employed desirably in antiperspirant compositions herein is represented by the
following empirical general formula: ZrO(OH)2n-nzBz .WH2O in which z is an integer or non-integer in the range of from 0.9 to 2.0, n is the valency of B, 2n - nZ is at least 0, B is selected from the group consisting of halides, including chloride, sulphamate, sulphate and mixtures thereof and w represents a variable amount of hydration, which may be zero. In preferred zirconium salts B represents chloride and z lies in the range of from 1.5 to 1.87. In practice, such zirconium salts are usually not employed by themselves, but as a component of a combined aluminium and zirconium-based antiperspirant, the aluminium component normally being selected in accordance with the above-mentioned formula for halohydrates. Especially desirable salts comprise mixed aluminium-zirconium chlorohydrates, optionally activated.
It will be recognised that the above-identified formulae for aluminium, zirconium and aluminium-zirconium salts are empirical and encompass compounds having co-ordinated and/or bound water in various quantities as well as polymeric

species and mixtures and complexes. In particular, zirconium hydroxy salts often represent a range of salts having various amounts of the hydroxy group.
Antiperspirant complexes based on the above-mentioned astringent aluminium, zirconium and aluminium-zirconium salts can desirably be employed in the present invention. Preferably, aluminium halohydrate and/or zirconium chlorohydrate materials are complexed. The complex often employs a carboxylic acid or carboxylase group, and advantageously an aminoacid. Examples of suitable aminocacids include dl-tryptophane, dl-β-phenylaniline, dl-valine, dl-methionine and β-aniline, and preferably glycine which satisfies the formula CH3(NH2) CO2H.
It is highly desirable in some embodiments to employ complexes of a combination of aluminium halohydrates and zirconium chlorohydrates together with aminoacids such as glycine, such as those disclosed in US^A3792068 (Luedders et al), Certain of those Al/Zr complexes are commonly called ZAG in the literature. ZAG actives generally contain aluminium, zirconium and chloride with an Al/Zr ratio in the range of 2 to 10, especially 2 to 6, a ratio of (Al-Zr) / CI in the range of 2.1 to 0.9 and a variable amount of an amino acid, particularly glycine. Actives of this preferred type are available from Giulini, Summit and Reheis.
Some formulations may contain activated ZAG complexes which are produced by the process disclosed in USP 5486347

(Callaghan et al) and which are subsequently dissolved in the aqueous phase of the dispersion.
The mole ratio of metal to chlorine in astringent aluminium or aluminium-zirconium slats employed herein is often selected in the range of from 0.9:1 to 1.5:1.
The weight proportion of the antiperspirant salt in the composition is often at least 10% by weight, and in many instances is up to 25% by weight. The concentration of the antiperspirant salt in the aqueous phase is often not greater than 25% w/w and particularly up to 22% w/w of the aqueous phase. Its concentration is usually at least 12% w/w and advantageously at least 15% w/w of the aqueous phase.
The weight proportion of water in the composition is at least 52% being the difference between the minimum 82% for aqueous phase and maximum 30% antiperspirant salt. In practice, the proportion of water is usually at least 60% by weight and particularly at least 65% by weight of the composition. In many desirable compositions, the proportion of water is not greater than 80% by weight and in various preferred compositions, the proportion is selected in the range of from 70 to 76% by weight of the entire composition.
In a number of suitable cream compositions according to the instant invention, the weight ratio of the continuous aqueous phase to the dispersed hydrophobic phase containing wax and oil is selected in the range of from at least 10:1 and often at least 12:1 to 15:1.

By the suitable selection of the constituents of the dispersion and their weight proportions it is possible to produce a cream having a viscosity in the region of from 30000 mPA.s (centipoise) to 150000 mPa.s which would be suitable for packing in sachet and big nose packs. It is particularly desirable to balance the proportions of the wax and the oils, the proportions of the aqueous and water-immiscible phases and the proportions of the high and complementary emulsifiers as well as the overall weight of emulsifiers to obtain a cream having a viscosity of from 80000 or/and up to 120000mPa.s. Herein, viscosity values quoted are those measured at 25°C using a Brookfield viscometer and employing the relevant spindle rotating at 6 rpm.
The dispersions according to this present invention can be made by any known process for making aqueous dispersions containing an ionic salt, such as an astringent antiperspirant salt.
One effective generalised process comprises in step i), mixing the emulsifiers with the wax in a pot and.heating the resultant mixture with continuous stirring until the wax has melted, often to a temperature of at least 80°C, such as from 95 to 100°C. Thereafter, in step ii), any oil, with the exception of fragrance oil, and any silicone elastomer are introduced with stirring to keep the mixture mobile. In a second vessel, in step iii), simultaneously or sequentially with step i) or ii) any particulates for suspension in the dispersion are suspended with stirring in a fraction of

water. In step iv), which can be carried out simultaneously with, or before or after step i) or ii), a further vessel is charged with the remainder of the watejr, except for water present in a solution of astringent antiperspirant salt, the suspension, if any, from step iii) is slowly introduced, and the resultant aqueous phase is heated to above 70°C, such as from 75 to 80°C. In step v) the product of step ii} is introduced with energetic mixing, such as via a recirculation loop, and the resultant mixture is homogenised. The resultant mixture in step vi) is allowed to cool slowly, with stirring rather than under homogenising mixing conditions at a rate .not exceeding about 1°C per minute until the mixture has attained a temperature in the region of 60°C, whereupon in step vii) the fragrance oil and in step viii) (which might precede step vii), an aqueous solution of the astringent antiperspirant salt are introduced, preferably separately, and preferably under homogenising mixing conditions either during or shortly after introduction of each material. Thereafter, in step ix), the homogenised dispersion is cooled.at the rate likewise not exceeding 1°C per minute until it has attained a temperature in the region of 40 to 45°C. in practice, the dispersion is often filled into the selected dispenser, commonly a sachet or a big nose pack, at that temperature, or more desirably, it can be allowed to cool further to ambient.
The dispenser of choice for the invention cream dispersion is conveniently a sachet, commonly made: from a multilayer laminated sheet, such as from 2 to 4 layers. In some very desirable embodiments, the sachet is fitted with a tubular

nozzle to form a big nose pack. In a big nose pack, the nozzle commonly comprises an externally screw-threaded neck extending outwardly from an integrally moulded shoulder that fits into one edge of the sachet. For distribution, the nozzle is fitted with a screw cap. The tubular nozzle can be employed in its own right to discharge the contents of the sachet onto a suitable applicator surface. If desired, the nozzle is connectable to an applicator having an interior duct opening at one end onto an applicator surface and at the other end in fluid communication with the sachet via the tubular nozzle.
Some sachets are made from a laminate that comprises three layers, such as an exterior polyester film, a metallised polyester film or foil and a low density polyethylene {preferably linear) interior film. A suitable example comprises a 12 micron Polyester film reverse printed bonded to a 12 micron metallised Polyester film bonded on its other face to a 30 micron linear low density polyethylene (LLDPE) film. All layers can be bonded together with low density polyethylene (LDPE), e.g. 15microns, by means of a conventional extrusion lamination process.
In some embodiments, the sachet is made from a tetralayer laminate comprising an exterior polyester film, an aluminium foil or metallised polyester film, a polyester film and an interior LLDPE film. A suitable example comprises a 12 micron polyester film reverse printed bonded to a 9 micron aluminium foil bonded on its other face to a 12 micron polyester film itself bonded on its other face to a 100 micron LLDPE film. The layers are bonded together with

conventional solvent based adhesive known to be suitable for polyester laminates.
In a big nose pack, the integrally moulded tubular nozzle and shoulder are conveniently made of HDPE (High Density Polyethylene) and the cap for the tubular nozzle is commonly made from PP (Polypropylene). .
For safe and secure distribution, the big nose pack often employs an additional layer of packaging. The outer layer conveniently is made from a 2 layer laminate sheet, such an exterior polyester film and an interior LLDPE film, for example -a 12 micron polyester film reverse printed bonded to a 25 micron LLDPE film. The films are bonded together with a conventional solvent based adhesive known to be suitable for polyester laminates.
The sachet, which is commonly rectangular or square, can be made in a conventional way, such as by folding a single sheet along the middle of the sheet, so that the two edges of the sheet are proximate and heat welded or otherwise sealed along the two opposed sides of the sachet extending from the middle to the proximate edges. Alternatively, two sheets of similar dimensions can be juxtaposed and heat welded or otherwise sealed along three sides.
The sachet can be filled by opening the non-sealed edge to form a mouth in a conventional manner, e.g. opposed pressure on the two opposed sealed edges or by separating the two sheets by applying external suction to them, and a predetermined dose of the invention dispersion is injected

or otherwise introduced through the mouth. The sheets are then pressed together adjacent to the mouth and sealed. For the manufacture of the big nose sachet, instead of the fourth side being sealed, a tubular nozzle integral with an applicator dome is oriented with its opening within the open fourth side, and heat welded to the laminate.
Although the dimensions of the sachet are at the discretion of the manufacturer, the sachet commonly is dimensioned to accommodate from 3 to 20 mls of dispersion. For simple sachets, the sachet commonly accommodates from 3 to 10 mls, such as 5 mls. This volume can conveniently be obtained by dimensioning the sachet walls to have, for example, a total edge length of from 15 to 40 cms, often 25 to 30 cms. Where the sachet forms part of a big nose dispenser, the sachet often is dimensioned to accommodate from 10 to 20 mis, such as 10 to 14 mls. The edge length of such sachets is often selected in the range of from 25 to 55 cms such as 30 to 40 cms.
Although the sachets have been described in relation to rectangular or square sachets, it will be recognised that the process could be adapted to other shapes, such as triangular, which may or may not be regular, and the sides of which may be straight or curved (other than for the mouth which advantageously is straight).
Advantageously, by selecting the emulsifiers and wax and any oils in the amounts and weight ratios described according top the present invention, naturally also taking into account the respective proportions of the aqueous and water-

immiscible phases, the resultant dispersion simultaneously meets the criteria of being able to be dispensed easily from a sachet and also exhibiting high temperature stability, a stability that is demonstrably superior to alternative formulations not according to the instant invention.
The invention dispersion is readily dispensed from a sachet in conventional manner, which is to say by opening the sachet along one edge, for example by cutting, or if the sachet at its edge includes a weakened point, tearing at that point. Application from a big nose pack conveniently comprises removing the cap from the tubular nozzle. The dispersion is most conveniently dispensed onto an applicator surface, which for the underarm can advantageously comprise a dome or, quite often, the fingers. The dispersion is then topically applied to the skin surface, often gently rubbing the applicator surface on the skin to apply the dispersion reasonably evenly. The weight of dispersion applied is at the discretion of the user, and for many users is in the range of from 0.1 to 0.5g per armpit, and advantageously at least 0.3g.
The timing of application of the antiperspirant dispersion is at the discretion and under the control of the user. Many users adopt a routine in which the antiperspirant is applied to the skin, such as the underarm, once or twice a day, and commonly after washing or showering, such as in the morning when they get up and/or shortly before they go to bed. Alternatively or additionally, some users apply the antiperspirant shortly before an event where they wish to keep their armpits dry.

Having described the invention generally, specific embodiments will now be given in more detail by way of example only.
Examples 1 to 9 and Comparisons A to E
In these Examples and Comparisons, the following ingredients were employed:-

The silicone elastomer1 is supplied as a solution of about 10% active by weight in a cyclomethicone carrier oil, that is predominantly D5 (cyclopentadimethylsiloxane).

The ACH solution2 is a solution of 50% by weight of aluminium chlorohydrate in water.
The fragrance3 was the same fragrance in all the Examples and comparisons.
The dispersions in the Examples and Comparisons were made by the following general method, varying ingredients in accordance with the following Table, and tested in accordance with the procedures given hereinafter.
The general preparation process at bench scale comprised in step i), mixing the emulsifiers with the wax in a pot and heating the resultant mixture with continuous stirring until a temperature of from 95 to 100°C had been reached, thereby ensuring that the wax or waxes had melted.
Thereafter, in step ii), the silicone elastomer and any oil, with the exception of fragrance oil, were introduced into the molten mixture obtained in step i) with stirring to keep the mixture mobile.
In a second vessel equipped with an anchor stirrer, in step iii), after step ii), the particulate titanium dioxide was suspended with stirring at medium speed in a fraction of the water.
In step iv), which was carried out after step ii), a further vessel equipped with a recirculation loop and a Silverson homogeniser was charged with the remainder of the water, except for water present in the ACH solution (astringent

antiperspirant salt solution), and the suspension made in step iii) was slowly introduced, and the resultant aqueous phase was heated to about 75 to 80°C.
Thereafter, in step v) the product of step ii) was introduced with energetic mixing, via a recirculation loop, and the resultant mixture was homogenised for about 2 minutes. The resultant homogenised mixture in step vi) was allowed to cool slowly, with stirring without homogenisation at a rate approaching, but not exceeding about 1°C per minute until the mixture has attained a temperature in the region of about 61/62°C, whereupon in step vii) the fragrance oil was introduced slowly and thereafter homogenised for about 2 minutes.
Thereafter, in step viii) when the dispersion had reached a temperature of about 50 to 59°C, in particular 52 to 56°C in favoured options, the aqueous ACH solution was introduced and the mixture homogenised again for about 2 minutes. Thereafter, in step ix), the homogenised dispersion was cooled at the rate likewise approaching but not exceeding 1°C per minute until it has attained a temperature in the region of 4 0 to 45°C. The product was then allowed to cool to ambient temperature overnight. This temperature was suitable for filling into sachets and big nose packs.

From the Table, it can be seen that the stability at elevated temperature of the Example compositions was significantly better than that of those not according to the invention.
The Viscosity of the dispersions was measured 12 hours after their preparation and at laboratory ambient temperature (close to 25°C) which allowed time for any post-preparation change in the viscosity of the composition to occur. The

viscosity measurement was made using a Brookfield viscometer, Model - LVT with helipath and equipped with a TF Spindle rotating at 6 RPM .
Procedure - Allow the tip of the T bar (TF) spindle to touch the dispersion surface. Its rotation and helipath were started simultaneously and the viscosity measured at the end of one minute.
High temperature Dispersion Integrity Test. The stability of the dispersion, by which herein is meant whether it retains its integrity during storage or separates into two layers, was measured at 65°C in order to indicate whether the dispersions were liable to become unstable during transportation and storage in tropical conditions, where temperatures in transit or in storage warehouses can exceed 50°C. The Integrity (stability) test was carried out as follows:-
A medicinal flat glass bottle of 100 mis capacity was filled with the sample of dispersion to be tested and heated to 65°C in an oven having a glass window. The bottle of dispersion was observed at every hour for the first 8 hours and at 24, 48 and 72 after being placed in the oven, to see whether the dispersion had retained its integrity or had begun to separate, forming an upper oily layer and/or a translucent bottom water layer.
Example 10

In this Example, a rectangular sachet of dimensions 5cm x 8cm having sidewalls made from a 3 layer laminate comprising an exterior 12 micron polyester film reverse printed bonded to a 12 micron metallised Polyester film bonded to an interior 30 micron linear low density polyethylene (LLDPE) film. All layers had been bonded together with 15 microns low density polyethylene (LDPE), by means of a conventional ■ extrusion lamination process,- and heat sealed along 3 edges is opened along an unsealed shorter edge and a predetermined volume of the dispersion of Example 5 (5mls) is squirted into the sachet and its open edge heat sealed.
Example 11
In this Example, a sachet of a dispenser illustrated in Figures 1 and 2 is filled with 12mls of the dispersion according to Example 7.
Figure 1 represents a perspective view of the dispenser with cap in place and Figure 2 represents a cross section through the dispenser of Figure 1.
A rectangular sachet (1) of dimensions 6cm x 9cm having sidewalls (2a, 2b) is made from a tetralayer laminate comprising an exterior 12 micron polyester film reverse printed, bonded to a 9 micron aluminium foil bonded to a 12 micron polyester film bonded to a 100 micron LLDPE film, the layers being bonded together with conventional solvent based adhesive known to be suitable for polyester laminate. The laminates are bonded along the two long edges and 1 short edge, the remaining side receiving an integrally moulded

shoulder (3) and tubular nozzle (4). The tubular nozzle is suitable for connection to with a domed applicator (not illustrated) having a central aperture through which fluid can be passed onto its exterior surface. The tubular nozzle
(4) is closed by a cap (5).
The dispenser after filling is assembled by opening the non-sealed edge of the sachet (1) to form a mouth. The shoulder
(3) integral with connector (4) with cap (5) fitted) is oriented in line with the sachet and placed within the sachet mouth and heat welded to the laminate material forming the sachet walls (2a, 2b) .
The big nose dispenser is then sealed within an exterior wrapping (not illustrated) made from a sheet of a 12 micron polyester film reverse printed and bonded to a 25 micron LLDPE film.

CLAIMS
1. An aqueous antiperspirant composition in the form of A
dispersion comprising
an aqueous phase in an amount of from 82 to 91.5% by weight, containing a soluble astringent antiperspirant salt in an amount of from 5 to 30% by weight, a water-immiscible phase in an amount of from 5 to 14.5% by weight, containing at least 0.5% by weight of an oil and at least 3% by weight of a wax and at least 3.5% by weight of a mixture of non-ionic emulsifiers comprising at least 1.5% by weight of a low HLB emulsifier having an HLB value of below 7 and at least 1.5% by weight of a complementary emulsifier having an HLB value such that the weight average HLB value of said mixture is at least 10.
2. A dispersion according to claim 1 in which the amount of the low HLB emulsifier is from 2 to 3% by weight and preferably from 2 to 2.5% by weight.
3. A dispersion according to either preceding claim in which the complementary emulsifier has an HLB value of at least 14.
4. A dispersion according to any preceding claim in which the complementary emulsifier is a mixture of emulsifiers, one of which has an HLB value in the range of from 14 to 17.

5. A dispersion according to any preceding claim in which the complementary emulsifier is a mixture of emulsifiers, one of which has an HLB value in the range of from 17 to 19.5.
6. A dispersion according to claim 4 or 5 in which the complementary emulsion comprises a mixture of two emulsifiers one of high HLB value and the other of higher HLB value in a weight ratio of from 1:1 to 2:1.
7. A dispersion according to any preceding claim in which the amount of the complementary emulsifier is from 2 to 4% by weight and preferably from 2.2 to 3% by weight.
8. A dispersion according to any preceding claim in which the low HLB emulsifier and complementary emulsifier are present in a weight ratio of from 0.75:1 to 1.1:1.
9. A dispersion according to any preceding claim in which the amount of wax in the water-immiscible phase is from 4 to 6% by weight.
10. A dispersion according to any preceding claim in which the wax comprises essentially a linear aliphatic alcohol having a melting point of at least 55°C or a mixture of said alcohols.
11. A dispersion according to claim 10 in which the aliphatic alcohol comprises from 16 to 24 carbon atoms or a mixture of said alcohols.

12. A dispersion according to claim 11 in which, the aliphatic alcohol comprises stearyl alcohol or a mixture thereof with cetyl alcohol.
13. A dispersion according to any preceding claim in which the proportion of wax is up to 6% by weight of the composition.
14. A dispersion according to any preceding claim in which the water-immiscible phase comprises a fragrance oil or oils.
15. A dispersion according to any preceding claim in which the water-immiscible phase comprises a volatile silicone oil.
16. A dispersion according to claim 15 in which the non¬volatile silicone oil comprises cyclopentadimethyl siloxanes.
17. A dispersion according to any preceding claim in which the proportion of oil is up to 4% by weight of the composition.
18. A dispersion according to any preceding claim comprising an oil-soluble silicone elastomer.
19. A dispersion according to claim 18 in which the amount of silicone elastomer is from 0.025 to 0.1% by weight of the emulsion.

20. A dispersion according to any preceding claim in which the water-immiscible phase comprises an aliphatic ether oil having a boiling point of over lOO^C.
21. A dispersion according to claim 20 in which the aliphatic ether oil comprises a polypropylene glycol ether.
22. A dispersion according to claim 21 in which the polypropylene glycol ether comprises an ether of an aliphatic alcohol containing from 14 to 20 carbon atoms.
23. A dispersion according to claim 20, 21 or 22 in which the ether oil is present in an amount of from 0.5 to 2% by weight.
24. A dispersion according to any preceding claim in which the water-immiscible phase is present in a proportion of from 6 to 9% by weight of the dispersion.
25. A dispersion according to any preceding claim in which the aqueous phase is present in a proportion of from 85 to 90% by weight of the dispersion.
26. A dispersion according to any preceding claim in which the astringent antiperspirant salt is an aluminium and/or zirconium chlorohydrate, optionally complexed.
27. A dispersion according to any preceding claim in which the antiperspirant salt is present at a concentration of from 10 to 25% of the composition.

28. A dispersion according to any preceding claim in which the composition contains from 65 to 80% water.
29. A dispersion according to any preceding claim in which the dispersion has a viscosity of from 30000 to 150000mPA.s.
30. A dispersion according to any preceding claim which retains its integrity when measured in the High Temperature Integrity Test for >8 hours.
31. A dispersion according to claim 30 which retains its integrity when measured in the High Temperature Integrity Test for >24 hours.
32. An antiperspirant product comprising a dispersion according to any preceding claim sealed in a sachet.
33. A product according to claim 32 in which the sachet is made from a laminate.
34. A product according to claim 33 in which the laminate comprises an interior polyethylene film and an exterior polyester film.
35. A product according to claim 32 or 33 in which the laminate comprises an aluminium foil or a metallised polyester film.

36. A product according to any of claims 32 to 34 in which the sachet is fitted with a tubular nozzle, preferably capped.