CA1115930A - Inhibition of perspiration - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

Improvement in combatting perspiration through the use of active antiperspirant compounds consisting of certain basic aluminium halides and nitrates which form in water an aqueous solution containing polymeric species having a size greater than 100 Angstroms within which at least 2? by weight of the aluminium is contained.

Description

~ 3~ J.~75 --~

~ his invention relates to the treatment of the skin7 more particularly to treatment of the skin to inhibit the 0xudation of perspiration.
For inhibiting perspiration9 the application to the skin of many different antiperspirant active compounds has been described in the literature. ~owever, those çompounds most widely used in commercial products at the pres~n-t time are basic aluminium halides, especially alumirliu~ chlorhydra-teS
which has an Al/Cl molar ratio of abo-l-t 2. These active compounds are applied to the skin from a ~arie-ty of applicator types including aerosol sprays, pump sprays, squeeze packs, roll-ons and stick applicators. ~hus aluminium chlorhydrate, for example, is employed as the active ingredien-t o~ various liquid9 cream, stick or dry powder antiperspirant compositions.
However, in spite of the popularity of aluminium chlorhydrate the presen-tly available products are capable o~ producing orlly limited reduction in perspiration.
It is an object of the invention to provide an improvement in the reduction of perspiration.
~he present invention is bassd on our discovery that in the employment of certain basic aluminium chloride, bromide, iodide and nitrate compounds, an improvement in antiperspirant ef~icacy is obtained through the use of those forms which in aqueous ~olu-tion contain polymeric species having a si~e greater than iO0 Angstroms in which species there is contained at least 2% by weight of the total aluminium.

~ _ . /
... "~

~ J.475 Since in aqueous solutions of the basic aluminium compounds the halide or nitrate is in ionic ~orm the polymeric species present are hydroxyaluminium species.
In one aspect therefore -the inventi.on relates to a method o~ inhibiting the exudation of perspiration by applying to the skin a polymeric antiperspirant compound which is a basic ..~ ,.. .
aluminium chloride, bromide, iodide or nitrate having an aluminium to chloride, bromide, iodide or nitrate molar ratio of ~rom 6.5 to 1.3:1, and which compound forms in water an aqueous solution con-taining species of a size greater than 100 Angstroms within which species there is contained a-t least 2%
by weight of the total aluminium.
The in~ention also relates to a package consisting of the combination of an antiperspirant composit ion comprising an antiperspirant active compound ancl an applicator for applying the antiperspirant composition to the skin, wherein the anti-perspirant active compound is a basic aluminium chloricle, bromide, iodide or nitra-te having an aluminium to chloride, bromide, iodide or nitrate molar ra-tio of from 6.S to 1.3:i~
and which compound forms in water an aqueous solution containing species of a size greater than I00 Angstroms within which species there is contained at least 2% by weight of the total aluminium.
Preferably the species having a si~e greater -than 100 2S Angstroms contain from S to 80%, more preferably 20 to 60%~ by weight of the total alum1nium. The solutions of polymeric basic aluminium compouncls referred to herein are meant to -- 3 -- / . . .

:

, : .

3~

include not only true solutions but also colloidal solutions or dispersions. Such solutions may corltain large colloidal polymeric species the upper limit for the size of which is not critical, it being required~ howe~er, that they can be dissolved or stably dispersed in water to ~orm a colloidal solution.
Usually, however, there will no-t be any substantial amo~mt of polymeric species exceeding 1,000 Angstroms in effective diameter~ although the aqueous solutions may he hazy or cloudy in appearance.
The package according to the invention may be one in which the applicator is a container fitted with a valve ~or dispensing liquid in aerosol form and the antiperspirant composition comprises a suspension of said antiperspirant active compouncl in particulate ~orm in a liquid carrier which ~ay be in admixture with a propellant. Furthermore, the package may be one wherein the applicator is a container ~itted wi-th a valve for dispensing liquid in aerosol form and the antiperspirant composition comprises an aqueous or aqueous alcoholic solution o~ said antiperspirant active compound. In this case the aqueous solution may be discharged by a propellan-t gas or by a finger-operated pump mechanism or by containing the composi-tion within a container of pliable material whereby by ~quee~ing the con-tainer the composi-tion is expelled through -the spray valve. Another form of package is one in which the applicator is a roll-on applicator and the an-tiperspirant composition comprises an aqueous or aqueous alcoholic solution of the said antiperspirant active compolmd. Furthermore, the package may - 4 - /Ø

~ J.~75 be one whereln the applicator is an applica-tor ~or dispensing a powdered material and the antiperspiran-t composition is a powdered composition including said an-tiperspirant active compound in powder form. The applicator may also be a stick applicator for holding an antiperspirant composition in the form o~ a stick or it may be tissue or cloth which is impregnated with the antiperspiran-t active material.
In accordance wi-th another aspect o~ the invention there is provided an antiperspirant composition comprising an aqueous solution of an antiperspirant active compound in combination with an adjunct which is a perfume, thickener, alcohol or propellant, wherein said compound is a basic aluminii~ chloride, bromide, iodide or nitrate having an aluminium to chloride~
bromide, iodide or nitrate molar ratio of from G.S to 1.3:1, said aqueous solution con-taining polymeric species having a size greater than lOO Angstroms within which species there is present at least 2~ by weight of the total aluminium. The antiperspi-rant composi-tion may be in the form of a lotion comprising an aqueous or aqueous alcoholic solution of the basic aluminium oompound in a concentration of from 1 to 30% hy weight and O.1 to 5% by weight of a thickening agentO Suitable thickening agents for antiperspirant lotions are well known to those skilled in -the art, and include for example, magnesium aluminilum silica-tes. Thickening may also be effectecl by emulsifying an oil or the like in the composition. Furthermore, the composition may comprise an aqueous or aqueous alcoholic solution O:e the basic aluminium compound in a concentra-tion of from 1 to 30g~o by weight and from O.i to 1c/~g hy weight of perfume .

_ 5 _ /---~ 3~ J.~75 The composition may comprise an aqueous alcoholic solution of the basic aluminium compound containing from 1 -to 60% by weight of an alcohol. These aqueous alcobolic compositions pre~erably contain ethanol or isopropanol as the alcohol which are preferably presen-t in an amount of' from about 1% to about 30%
by weight of the composition~ Antiperspirant compositions comprising an aqueous solution of -the active compo~d may contain from about 1 to 80% by weight of a propellant.
The antiperspirant composition may also comprise in combination a powdered antiperspirant active compound and a powdered inert solid diluent or organic liquid carrier, wherein said ¢ompound is a basic aluminium chloride, bromide, iodide or nitrate ha~ing an aluminium to chloride, bromide, iodide or nitrate molar ratio of from 6.5 -to 1.3:1, which compound forms when dissolved in water an aqueous solution containing species of a size greater than 100 Angstroms within which species there is contained at least 2% by weight o~ the total aluminium.
~he composition may be in the form o~ a powder aerosol composition comprising a suspension of the basic aluminium compound in particulate form in a liquid carrier, said composition also comprising a propellant. In particular the composition may be in -the form of a powder aerosol composition comprising A. from about 1% to about 12% b`y weight of said basic aluminium compound in powder form;

~ 6 ~

~ J.~75 B. from about 0.1~ to about 5% by weight o~ a suspending agent;

C. from about 1~ to about 15~o by weight of a carrier liquid; and D. from about 70% to about 96% by weight of a propellant.

The carrier liquid may ~or example be a non-volatile non-hygroscopic liquid as suggested in US Patent No.3,968,2V3.
Especially useful are carrier liquids which have emollient proper-ties and a number of these are referred to in British Patent Specification No.1,393,860. Especially preferred are ~atty acid esters such as isopropyl myristate and those esters re~erred to in British Patent Specification No.1~ 353~914 such as dibutyl phthalate and diisopropyl adipate.
Various other carrier liquids :~or powder suspension aerosols are suggested in US Patent Speci~ications Nos.
3,833,721~ 3,833,720, 3,920,80l, 3,949,066 and 3,~74,270, and in British Patent Speci~ications Nos.i, 341, 748, 1, 300~260~
1,369,872 and 1,41i,547. Volatile carrier liquids may also be used such as ethanol as described in South African Patent ~0 Speci~ication No.75/3576, and volatile silicones.

The ratio o~ total solids in the compositions to the carrier liquid may vary over a wide range, ~or example from 0.01 to 3 parts of the powder per part by weigh-t of the carrier liquid.

- 7 - /...

~-~ J.~175 The propellant can be a liquefied hydrocarbon, halogenated hydrocarbon or a mixture thereof. Examples of materials that are suitable for use as propellants are given in the above-mentioned patents and include trichloroflllorome-thane, dichloro-di~luoromethane~ dichlorotetrafluoroe$hane, monochlorodifluoro-methane, trichlorotrifluoroethane, propane, butane; 19 l-difluoro-e'thane, l,i-difluoro-l-chloroethane, dichloromono~luoromethane, methylene chloride, isopentane and isobu-tane, used singly or admixed. Trichloro~luoromethane, dichlorodi~luoromethane 9 dichlorotetrafluoroethane, and iso'butane, used singly or admised, are pre~erredO
Examples o~ materials that are suitable for use as permanent gas propellants are nitrogen, carbon dioxide and nitrous o~Yide.
15 It is common practice to include in aerosol powder spray compositions a material to assist in the suspending of the powder in the liquid vehicle. ~he materials prevent compacting o~ the powder and they may also act as thickening or gelling agents for the liquid ve'hicle~ Especially pre~erred are hydrophobic clays and colloidal silicas. Hydrophobic clays are available under the trade name Bentone, eg Bentone 34 or Ben-tone 38, and their use as suspending agents are described in a number o~ patent speci~ications including US Pa-ten-t Speci~ication No.3,773,683. Suitable colloidal silicas .~, .
~25 include Aerosil 200 and Cab-0 Sil M-5 as well as other grades.
The antiperspirant composition may, however, simply comprise ~rom 5 -to ~0% by weight of said basic aLuminium ~-r~i~ ~G~h compound in powder form, -the remainder consisting essentially Oe an inert powder material, such as talc or starch, eor example~
~ he basic aluminium compound may have the empirical formula s A1~(0~)6_a X~
where X is Cl~ Br, I or N03 a is ~rom 0.4 to 1.5 the formula in the case of the compoulld in solid form containing 0.5 to 8 molecules Oe water of hydration. Pre~erably the basic aluminium compound has an aluminium to chloride, bromide, iodide or nitrate molar ratio of from 4 to 1.6:i, mor~ particularly 2.5 to 1.6:1.
The invention also relates to a novel solid antiperspirant compound comprising a hydra-ted basic aluminium chloride, bromide, iodide or nitrate having a~ aluminium to chloride, bromide, iodide or nitrate molar ratio of from 6.5 to 1.3:1, and which compound when dissolved in water ~orms an aqueous solution containing species Oe a size greater than 1.0~ Angstroms within which species there is contained at least 2% by weight o.~
the total aluminium. The solid antiperspirant compound may have the empirical formula A12~0~)6_a Xa n~2 where X is Cl, Br, I or N03 _ is erom 0.3 to i.5 2S n i9 from 0.5 to 8.
In particular a may be from 0.5 to 1.5, preferably from 0.8 to i.2S. ~he solid compound preferably contains 0.5 to 4 molecules g _ / -~ 3~ J.~175 of water o~ hydration. A form of said solid compound particularly sui-table for use in aerosol powder spray compositions is one comprising particles having a size less than lO0 microns, preferably less than 44 microns.
In a further aspect, the invention relates to a novel aqueous solution of an antiperspirant compound in a concentration of from 7 to 22% or up to 600h by weight, said compound being a polymeric compound of the empirical formula Al2(0~)6-a Xa O whers X is Cl 7 Br, I or N03 a is from 0.3 to l.5, preferably from 004 to 1.25 said solution co~taining polymeric species having a size greater than 100 Angstroms within which species there is contained at least 2% by weight of the total aluminium present in said 5 compound, said solution being free of boehmite as determined by X-ray diffraction on the material dried at 50C under vacuum.
There is also provided by the present invention a novel aqueous solution of an antiperspirant compo~md, wherein said compound is a polymeric compound of the empirical formula A12(0H)6-a Xa where X is Cl, Br, I or N03 a is from V.3 to V.9 or from l.l to l.5 said solu-tion containing polymeric species having a si~e greater than lOV Angstroms within which species there is contained at 5 least 2% by weight of the tota]. aluminium.

, ~ 3~ J.47~

The invention also relates to a novel aqueous solution oY
a basic aluminium bromide, iodide or nitrate having an aluminium to bromide, iodide or nitrate molar ratio o~ from 6.5 to i.3:i, which solution contains polymeric species o~ the basic aluminium compound of a si~e greater than 100 Angstroms within which species there is contained at least 2% by weight o~ the to-tal aluminium. ~he solution may comprise the antiperspirant compound in a concentration of ~rom 1 to 60~ by weight, and said compound may be a polymeric compound of the empirical formula A12(~)6-a Xa where X is Br, I or N03 a is from 0.3 to 1.5, preferably ~rom 0.4 to 1.25 said aqueous solution containing polymeric species having a si~e greater than 100 Angstroms within which spccies is presen-t at least 2% by weight o~ the total aluminiumO
For the above novel compounds and solu-tions, there is preferably contained within the polymeric species having a size greater than 100 Angstroms ~rom S to 80%, more preferably 20 to 60%, hy weight o~ the total aluminium.
The above-described special ~orms of basic aluminium compounds which in aqueous solution contain polymeric species having a size greater than 100 Angstroms within which at least

2% by weight o~ the total aluminium is co~tained, may be prepared by heating aqueous solutions o~ the basic aluminium compo~mds at elevated temperature, as more particularly described herein. ~he production of -the desired species depends on the appropria-te choice o~ the reaction conditions which are in-ter-- 11 - /.

~ J.~75 related. It is preferred -to use temperatures of from 80C to i40C. The period of heating may be shorter as higher temperatures are used, ranging for e~ample from 0.5 hour to 30 days. 0~ importance is the concentration of -the basic aluminiuzn compound. At the above temperatures~ substantially no production of the higher polymeric species of the basic alumini~n compound has been observed with solutions having a concentration above about 40% by weight. At these temperatures, the concentration of the solution should be no more than about 35% by weight.
The conditions of heat treatment described above have been found to give rise to the improved basic aluminium compound in amorphous form, and in particular the formation of boehmite~ as determined by X~ray diffraction, has not been observed. ~he production of a substantial amount of boehmite or other crystalline forms of alumina would be consiclered to be disad-vantageous.
According to the invention a preferred process for making an aqueous solution of an antiperspirant compound comprises heating an aqueous solution of a compound of the empirical formula Al2tO~)6_a ~a where X is Cl, Br~ I or N03 a is from 0.3 -to 1.5 2~5 said solution having a concentration of from 7 to 3S% by weight, at a temperature of from 80C -to 140C for a tizne sufficient to give rise in said solution -to polymeric species having a size 1~5~ J.475 above 100 Angstroms in such amount that at least 2% by weight of the total aluminium is contained within such species.
A further embodiment o~ the production o~ an improved solution of an antiperspirant compound comprises heating an aqueous solution of a compound of the empirical ~ormula Al2(OH)6-a Xa where X i9 Br, I or NO3 a is ~rom 0.3 to 1.5 the concentration of such solution and its temperature and time of beating being such that there is produced in the solution polymeric species having a size above 100 Angstroms, said species being produced in such amount that at least 2% by weight of the total aluminium is contained within such species.
The aqueous solution o~ the more active an-tiperspirant compound comprising the higher polymeric species as defined, may, i~ desired, be evaporated to concentrate the solution or it may be dried to give the compound in the form of a solid hydrate. As with untreated aluminium chlorhydrate~ for example, drying conditions which lead to both the loss of water f condensation, bet~een the hydro~y groups o~ the compound, and hydrochloric acid should be avolded as -these may lead to irreversible degradation o~ the treated basic aluminium compound.
~ny suitable method o~ drying may be used, spray drying being a par-tioularly use~ul method. ~he spray drying method deseribed in US Patent No.3,88~,692 may be employed. The solid material may be ground or milled as required.

- i3 -~ J.475 Accordingly a preferred method of making an improved solid hydrated antiperspirant active compound comprises spray drying an aqueous solu-tion of a basic aluminium chloride, bromide, iodide or nitrate having an aluminium -to chloride, bromide, iodide or nitrate molar ratio of from 6.5 to 1.3:1, said solution containing polymeric species of a size greater than 100 Angstroms wi~hin which species there is contained at least 2% by weight of the total aluminium.
~he above processes are preferably conducted in such manner that within said species there is contained from 5 to 80%~ more pre~erably 20 to 60%~ by weight of the total aluminium.
The test methods for testing antiperspirant efficacy of various antiperspirant compositions referred to in the Examples given herein will now be described.

~ J.475 TEST METHODS FOR ASSESS~NT OF EFFICAC~ OF ~N~IPERSPIRANTS
In the Examples given therein five test methods are referred to for -the assessment of various antiperspirant active agents referred to therein. Details of the test procedures are described below.
Test Methods I to IV for the assessment o~ antiperspiraIlt efficacy depend on subjecting human volunteers to -thermal s-tress and gravimetric determination of axillar sweat.
Test PIethod I
10 Subjects A panel of up to 18 woman who use no antiperspirant ~or the 14 days be~ore the test or during the 16 day interval between the two halves of the test.

Ho~ Room Temperature ~7C ~ 1C, relative humidity approximately 35% .

Products Two to four products are tested, one of which is designated as the control.
Each subject receives a different trea-tmerlt on each axilla and as far as possible equal numbers of left and right axillae receive each treatment.

Product Application A two-second spray is administered.

-- 15 -- / . . .

~ 3~ J.~75 Sweat Collection Absorbent cotton pads are used to collect -the sweat. On entering the hot room each subject has a pair of pads placed in her axillae. After ~0 minutes these are removed and rejected. Sweat is then collected for -two consecutive periods of 20 minutes~ ~r~e~h tared pads being used ~or each collection~ a~d sweat w2ight de-termined.

T~s-t Design On the first day of the test the subjects receive treatment with the test products but do not undergo a hot rovm si-tting.
On each of the next 4 days they undergo hot room sittings, with treatment immediately before each sitting and after showering. The final treatment is '~ omitted on the fifth day. After an interval of 16 days the subjects re-turn and the whole procedure is repeated, with the two products received by each subjec-t applied to the opposite axillae.

Analysis of Data The statistical treatment includes an analysis of variance which allows for subject, side and product effects. The efficacy is calculated from the geometric mean weight of sweat collec-ted from the axillae treated with each procluct.

- 16 ~

~5~ J~475 /0 reduction = lOV ~

where C is -the geometric mean sweat weight from the axillae treated with the con-trol product ancl T is the geometric mean sweat weight from the axillae treated with the -test product. The %
reduction is usually calculated ~or each day separately and for the entire test.

Signi~icance is calculated -by applying Duncanis Multiple Range Test to the logarithmically transformed weights.

Test Method_II
Subjects A panel of up to 54 women who use no antiperspiran-t for the 14 days before the test.

Products Two aerosol powder spray products of _ .... . .
which one is designated the control.
-- - I'he panel i~ divided into two equal -groupsO One group receives the test treatment on the left axilla and the control treatment on the right, while the second group receives them the o-ther way round.

~ J.~75 Test Design Subjects attelld daily for 3 consecllt:ive days~ They receive one treatment ~ith the products each day. On the thiYd day the trea-tmen-t is imlllediately followed by a ho-t room sitting and sweat collectio~l.

Analysis of Data As for qest l~ethod I except that significance is calculated by applying Student's t-test to -the logarithmically transformed weights.

10 The products used in Test ~ethods I and II ~acl tbe composition indicated below.
In~redient ~est Prod ~ ~est P~oduct I.L (~) Treated or untreated3.50 l.50 aluminium chlorhydrate 15 Isopropyl myristate3.25 6.00 : Pyrogcnic ~ilica 0.10 0.~l5 (Aerosll 200) P~rfume 0.44 O.l~l .Propellant1 to 100.00 -to 100.00 20 1 CCl F:CCl2F2 - 65:35 by weight (product I)

3 50:50 by weight ~Produc-t II) ~es-t ~Iethod III
As Test Method II with -the following differellces:

J.475 Test Product 10% solution of treated aluminium chlorhydrate (unless stated otherwise) iIl water.

Control Product 10% solution of un-trea-ted aluminium chlorhydrate (unless stated otherwise) in water.

Method of Application Appro~imately 0.5 g of solution was applied to each axilla with a cotton swab.

Test Method IV
As Test Method III with the following dif~erences:

Method o~ Applica~ion Approximately 0,5 g of solution was appliea to each aYilla wi-th a pump-spray applicator.

Test Method V

This method is the Forearm Starch Iodine Patch '~est ~hich was conductad as follows (after Wada ~ Tokayaki in J~ Exp. Med~
49 284 (1948)).
A panel of volunteer test subjects was recruited and each ~ .
--- panellist had a number of test solutions applied to separate sites on -the volar aspect of the iorearm. '~he solutions (:L2 drops) were applied under semi-occlusive patches and left for 6 hours. The treatment region of the ~orearm was then painted -- 19 -- / . . .

~ 3~ J~75 wi-th several coats of a i% solution of iodine in alcohol.
After evaporation o~ the alcohol, the painted area was covered with a 50% suspension of starch powder in oil. The subject was then placed in a heated room (40 - 2C) until s~eating commenced.
The effectiYeness of the various treatments was then assessed on the basis o~ the number and si~e of blue spots arising from the interaction of starch, iodine and sweat.

Determina-tion of percentage aluminium in polymeric species havin~ a size ~reater than 100 An~stroms All heat-treated basic aluminium compounds described herein were defined by molecular sieve chromatography. For this purpose there was used a 1.2 m x 6.0 mm column packed with spherical porous silica beads of particle size 75-125 microns, and of sur~ace area 350-500 m2/g, and having a maximum pore 9 ize of 100 R. The silica employed, available commercially as Porasil AX, had been deactivated to eliminate adsorption in molecular size separations. The use o~ Porasil silica beads as a column packing in chromatography is referred to in "Gel Permeation Ghromatography" by K.E~ Altgelt and ~. Segan, 1971, pages 16 to 18. The silica was conditioned be~ore use by passage of a single large sample (eg 0.5 ml of a 2% WlW
solution) of a heat-treated aluminium chlorhydrate. Samples to be tested were dissolved in deioni~ed water to approximately 0.2 M aluminium and -thoroughly dispersed by treatment (4 minutes) ~5 with a sonic probe. About 0.1 ml samples of approximately 0.2 M
aluminium solutions were applied to the column by a sample loop system and eluted with 10 M aqueous hydrochloric acid solution GIc~

_ 20 - /

~ J.~75 using a peristaltic pump. A differential refractive index monitor linked to a pen recorder was used to detect fractions as they were eluted. ~hese fractions were collected and analysed for aluminium by atomic absorption. Complete elutior --- 5 of all aluminium applied in each samp:Le was checked by direct analysis of another sample of the s~me volume. ~he percentage of the total aluminium which appeared in -the fraction elu-ted at the void volume of the column was considered as that deriving from polymeric material of a sise greater than 100 R in effective diameter. None of this polymeric material was ~ound in any untrea-ted aluminium chlorhydrate solutions.

Determination of water content of Powdered materials The water conten-t of powdered materials was estimated by thermogravimetric analysis (~GA). On heating to 1,000C, aluminium chlorhydrate undergoes the ~ollowing reac-tion:
Al2(0E)scl(~2o)x -- ~ A1~03 ~ HCl~ + (x + 2)H20~
From a knowledge of Al/Cl ratio o~ the material (and hence the empirical weight of the anhydrous Al2(0H)6 aCla) it is possible to calculate the number o~ moles of water (x) associated with each anhydrous unit from an accurate determination of the weight loss on heating a known weight of sample to 1,000C. The following equation shows the method of calculation:

~ Wei~ht O:e solid before heati_~ 2~ Empirical weight x ~ Weight of solid a~ter heating x 10 J o~ anhydrous ~Al2(OH)6_aCla7 -- 2i - l ~ 3~ J,475 The percentage o~ water is given by 1 t 800x Empirical weight of anhydrous 12( H)6 aCla 18x -__ 5 The following Examples illustrate the invention.
Exam~
Aluminium chlorhydrate powder having an Al/Cl molar ratio of 2.04 and a water con-tent of 18.5% was dissolved in deionized wa-ter so as to give a 10C/o W~w solution. This solution was heated in 1 litre screw-cap glass bottles to 96C over 9 hours and then held at this temperature for a further 39 hours. The resulting solutiorl was cooled -to room temperature and found to contain 27.3% of the total aluminium as polymers exceeding 100 R
in e~ective diameter. The treated solution was spray dried in i5 a co-current spray drier using inlet and outlet te~peratures of 250C and 95C, respectively. The resulting powder had an Al/Cl molar ratio o~ 2.10 and a water content of 1~.2%. The powder was ~ieved to obtain a ~raction between 30 and 50 microns.
The spray dried powder was tested for antiperspirant efficacy in two tests using Test Method I.
~est No.1 .
This test involved 17 subjects.
Test Products Test Product I made with -the treated aluminium chlorhydrate. Two Test Products I made with untreated aluminium chlorhydrate drawn ~rom two dif~erent production batches, Control Product An alcohol-based deodorant.

_ 2~ -.

~5~;3~ J.475 Results Percent reductions for the products against the control are shown in ~able I.
"Day 2" refers to the combined results for the second days of each of the 2 weeks 9 and so on through the table.
The table gives the mean of the results for the two products containing untrea-ted aluminium chlorhydrate.
Table I
lO Test Product Day 2 Day 3 Day 4 Day 5 Overall .
With untreated 7 l5 22 22 l~
aluminium chlorhydrate With treated 32 ~2 47 56 45 aluminium chlorhydrate The differences be`tween the antiperspirants with treated and untreated aluminium chlorhydrate were significant at the 1% level.
Test No.2 This was a repetition o~ ~est No.l using the same products on 14 different subjects.
20 Results Percent reductions for the products against the control are shown in Table II
where the column headings have the same meanings as before.

_ 23 -:
.: , ~.
,. . ;

~ J.475 Table _ ?est Product Da~2_~ Da~ 5 Overall With untreated 22 16 29 2~ 24 aluminium chlorhydrate With treated 34 37 44 44 40 aluminium chlorhydrate The differences hetween the antiperspiran-ts with treated and untreated aluminium chlorhydrate were again significant at the 1% level.
Example 2 A batch of Reheis alumini-um chlorhydrate Microdry, Ultrafine grade having an Al/Cl molar ratio of 2.04 and a water content of 1805% was dissolved in deioni~ed water to give a 10%
~/w solu-tion. ~his solution was heated in i li-tre screw-cap glass bottles to 97-100C over 10 hours and then held at this temperature ~or a further 38 hours. The resulting solution was cooled to room temperature and found to contain 23~9% of the total aluminium as polymers exceeding iOO ~ in e~fective diameter. The solution was tested ~or antiperspirancy according to Test Method III using a test panel of 46 subjects.
The test solution produced a reduction of 22% in the sweat collected comparea with the con-trol ( 10% solution o~ untreated aluminium chlorhydrate solution), which was statistically significant at the 0.1,h level.
The treated solution was then spray dried and the powder sieved as described in Example 1 to give a material with an Al/Cl molar ratio of 2.14 and a water content o~ 14.3%. The powder was tested according to Test l~ethod II (with 43 panellists) - 24 _ /

3~
J.475 (CA) using a suspensicn~ype aerosol antiperspirant of formula according to Test Product I. The product containing the treated aluminium chlorhydrate gave a 25~ red~ction in sweat compared with the control product containing the - ~ untreated aluminium chlorhydrate which was significant at the 0.1% level.
Example 3 5.0 kg of Reheis aluminium chlorhydrate having an Al/Cl molar ratio of 2~15 and a water content of 16.1~ was dissolved in 45 litres of deionised water at 50-6GC in a 50 litre stainless steel reactor internally spray-coated with polytetrafluoroethylene and equipp~d with a pr~peller stirrer an~ partial steam jacket. The solution was stirred and heated to lOO~C in the closed reactor over 10 minutes, then held at this temperature with stirring or 48 hours. After this time the solution was cooled to ambient temperalure and homogenised to disperse any gel tha~ may have been formed. The solution contained 43.3~ of the total aluminium as polymers greater than 100 ~ in effective diameter. When tested for antiperspirancy according to Test Method III with a panel of 19 subjects and using as control the 10% solution of treated aluminium chlorhydrate of Example 2, the test solution produced a redùct~nof 10% in the sweat collected~ the difference being statistically significant at the 10% level.

Example 4 5.0 kg of aluminium chlorhydrate (sold as Reheis aluminium chlorhydrate Microdry, Ultrafine grade) having an Al/Cl molar ratio of 2.15 and a water content o 16.1~ was dissolved in 45 .
:

~5~ J.475 litres of deionized water at 50-60C in the reactor described in Example 3. The solution was stirred and heated to 120C
in the closed reactor over 15 minutes, and then held at this -temperature with stirring for 6 hours. After this period, the S solu-tion was cooled to 90C over 15 minutes, then discharged in-to a holding vessel and allowed to cool to ambien-t temperature.
Before ~urther treatment, the solution was passed -through a homogeniser. This solution containecl 40.~% of the total aluminium as polymers exceeding 100 R in e~fective diameter, When tested for antiperspirancy according to Test Method III with a test panel of 42 subjects and using as con-trol the 10%
solution o~ the treated aluminium chlorhydrate of Example 3, the solution produced a reduction of l~/o in the sweat collected.
The difference was not statistically significant a-t the 5~
level.
A portion of the treated solution was spray dried by the method described in Example 1. ~he resulting powder had an Al/Cl ratio of 2.23 and a water content o~ 11. 2% . The powder was sieved to obtain a iraction between 30 and 50 microns 20 which was incorporated into a suspension-type aerosol antiperspirant (Test Product II formula) and compared according to Test Method II (using a panel of 51 subjects) with a once commercially available highly ef~ective powder spray product based on a ~irconium/alumillium complex as control and ~ound to give a reduc-tion of 7% in the sweat collec-ted. This was not statistically significant at the 5% level.

~ 2~

s~
J,475 When a sample o~ the spray dried powder was heated for 2 hours at 120C the dried product obtained had the empirical formula A12(0H)5 31Clo 6g. The solution obtained on dissolving this anhydrous powder in water was shown to contain 4$.4~o by weight o.~ the total aluminium in polymers having an effective diameter o~ more than 100 R.
~xam~le 5 10 kg o~ a 50% W/w solution of aluminium chlorhydrate D (available commercially as Reheis "Chlorhydrol';) which haa an Al/Cl molar ratio o~ 2.09, was added to 40 litres of deionized water and the resulting solution was stirred and heated at 120C
~or 6 hours in the closed reactor as described in E~ample 3.
The treated solution contained 32.9% Of the total aluminium as polymers exceeding 100 R in ef~ective diameter and when compared by Test Method III on a panel o~ ~5 subjects with the 10% solution of treated aluminium chlorhydrate of Example 4 as control gave a 2~ increase in the sweat collected but this was not statistically 9 ignificant at the 5% level.
A portion of the treated solution was concentrated Imder vacuum in a rotary evaporator at 40C to give a solution which was 1.62 molar in aluminium equivalent to 17.1yo treated aluminium chlorhydrate.
A further portion o~ the solution was spray dried by the procedure described in Example 1 to give a powder which had an 2S Al/Cl molar ratio of 2.05 and a water content of 12.7%. A
sample of this powder was redissolved in deionized water and was shown. to contain 32 . 4% of the -total aluminium as polymers o~ a f ~ C~ L~ ~^ k _ 27 -~5~ J.~75 size exceedlng 100 ~. The powder was sieved to give a 30-50 micron ~raction which was formulated into a suspension--type aerosol an~iperspirant (Test Product II). This was compared using Test Method II (involving 48 panellists) with the same powder spray control as used in Example 4 and it gave a 14%
reduction in sweat collected which was statistically signi~icant - at the 5% level.
xample ~
A solution of aluminium chloxhydrate was prepared as described in Example 3 and was stirred and heated to i20C in -the closed reactor over i5 minutes. Stirring and heating at this temperature was continuecl and after 1 hour, 6 hours and 25 hours samples of approximately 2 kg of the solution were withdrawn ~rom the reactor, cooled rapidly to room tempera-ture and homogenised. These solutions contained 19.4%9 45.1% and 78.4%~ respectively, of their total aluminium as polymers exceeding lO0 ~ in ef~ective diameter. The results of antiperspirancy -tests on these materials by Test Metbod I~
are included in Table III.
Exam~e 7 Reheis aluminium chlorhydrate, Microdry, Ultra~ine grade having an Al/Cl molar ratio of 1.91 and a water content of 18.8%
was dissolved in deionized water to give a 10% W/w solution.
This solution was placed in 25 ml Pyrex screw-cap tubes equipped with polytetra~luoroethylene washers and heated to 115C in an oil bath for 2 hours. The solutiorls were cooled to ambient temperature and ~ound to contain 5. 3% of the total _ 28 -,7.~75 aluminium as polymers grea-ter than 100 R in effective diameter.
The result of antiperspirancy testing of this solution, by Test Method IV7 is shown in T~hle III.

_ 29 ~

J,~5 _ ~ ~ ~¢ .
o ~ ~
O
O C- ~ ~1 ~1 ~,1 _ __ t~
___ _ ,~
q~
o o ~ ~ C`J
~ C~ ~ ~
Z ~
_ _ ~ _ ~ ~ o ~_, ~ :5 ~1 U~ O U~ U~ U~ ~ ~
q~ ~ Gq 5 .~;~
U~ ~ ~
,1 ~o ,1 o o oo 1 o ~ C~ C~ C" ~ ~.
9~ I I I I +
~t ~ U~

E~ ~ . ~ .

O D

. ~ O
~ ~ ~ 3 ,,~ bDO
a~ 3 1~ ~ ~ o C'~ O
E-l ~ O O ~Q ~ t~ , ~ ~ o _ _ _ _. ~ ~ ~ O
O ~ .1 ~'3 .,1 +~
Cd O ~ a ::~ a) t~
~_ o ~ ~ a~
U~
+' 5 ~¢
E~ I ~ .~ .~ ./
. I
- ~ O U~ o .1 .1 C~
- 3U _ ~ !

~ J,475 ExamE~8 70 kg of a Reheis aluminium chlorhydrate having an Al/Cl molar ratio of l.9i and a water conten-t of 18.8C/o was dissolve~
in 630 kg o~ deionized water at 45C and s-tirred and heated to 120C in a stainless steel reactor over 3.7~ hours. Stirring and heating at this temperature was maintained for a further 5.5 hours before cooling rapidly -to 70C and more slowly to ambient temperature. ~he resulting ~olution contained 41.0% of the total aluminium as polymers exceeding 100 ~ in e~fec-tive diameter.
E~ample 9 ~ 40 kg of Reheis "Chlorhydrol" solution having an Al/Cl ratio of 2.09 was diluted with 560 litres of deionized water at 45C and treated in a similar manner in the reactor as described for the solution in Example 8. ~he resul-ting solution was 15 found to contain 30.6% of the total aluminium as polymers greater than 100 ~ in ef~ective diameter.
~ le 10 30%~ 20%~ 15%~ 5% and 2% W/w solutions of a Reheis aluminium chlorhydrate having an Al/Cl ratio of 1.91 and a water content of 18.8% were prepared and heated to 120C in 25 ml Pyre~Y~glas~
screw-cap tubes ~ equipped with poly-tetra~luoroethylene washers, in a fan oven for 6 hours. The resulting solution~ contained 0%~ 6.3%~ 20.8%~ 31.1% and al.60/O respectively, o~ the total aluminium as polymers exceeding 100 ~ in ef~ective diameter.
~ 7f~7~ a ~k -: :

:

~5~ J.~75 Example 11 A more acidic aluminium chlorhydrate was prepared by mixing together 19.0 g of an aluminium chlorhydrate, having an Al/Cl molar ratio of 1.91 and a water content of 18 .8%~ 2 .25 g of aluminium chloride hexahydrate and sufficient deionized water to give 1 kg of solution. Some of this solution was placed in 25 ml Pyrex screw-cap tubes equipped with polytetrafluoroethylene washers and heated to 120C for 24.5 hours in a fan oven. The solutions were cooled to ambient temperature and found to have an Al/Cl ratio of 1.6. 40.5% of the total aluminium in this solution was found in polymers greater than 100 ~ in effective diameter.
Example 12 A more basic aluminium chlorhydrate solution was prepared i5 by heating a solution of 36.3 g of aluminium chloride he~ahydrate in 150 g of deionized water in the presence of 145 g of 0.5 mm thick aluminium metal sheet, subdivided to approximately 6 mm square9~ at 90C for 3i hours. After cooling to room tempera~ure the solution was decanted from the excess aluminium and found to have an Al/Cl molar ratio of 2.5 a~d 0% of the total aluminium as polymeric species exceeding 100 ~ in effective diameter.
This solution was diluted to an aluminium concentration of 0.95 M
and a portion of the diluted solution was heated at 120C for 8 hours in 25 ml Pyrex glass screw-cap tubes, fitted with poly-tetrafluoroethylene washers, in a fan oven. The cooled solutioncontained 37.6% of the total aluminium as polymeric species exceeding 100 .~ in effective diameter and when compared by Test ~ J.~75 Method I~, on a panel of 20 subjects, with the non-heat-treated diluted solution as control, gave a 36% decrease in the swea-t collected which was significant at the O.lyo level.

A 10% W/w solution o~ a basic aluminium bromide having an Al/Br molar ratio of 2 and a water con-tent of about 22% was prepared and heated to 100.G in a 1 li-tre screw-cap glass bottle ~or 62 hours in a fan oven. The resulting solution was in~ediately cooled to room temperature and found to contain 46.4%
o~ the total aluminium as polymers esceeding 100 R in effective diameter. When tested for antiperspirancy using Test ~ethod V
this solution was ~ound to be appreciably more eY~ective than an untreated solution o~ the basic aluminium bromide at the same ._ concentratio~.
~amele 14 A basic aluminium nitrate was prepared by dissolving 37.4 g o~ aluminium ~itrate nonahydrate in deionized water to give 200 g of solutionO ~he solution was heated to 90C urLder a reflux condenser and i3.45 ~ of aluminium powder was added in small portions over a period o~ 5 hours. Eeating was then con-tinued with stirring for a ~urther 24 hours. AI'ter this period, the solution wag cooled to room temperature and filtered to remove èxcess aluminium and was ~ound to have an Al/nitrate molar ra-tio of 2.9. ~ of the total aluminium in this solution was ~ound in species which were greater than 100 ~ in ef~ective diameter. Some of this solution was diluted to be . ., ~.
0.1 ~ in aluminium and tested for antiperspirancy using ~est - 33 - /~o J.475 ~ethod V and was found -to be equivalent in efficacy to the solu-tion prepared in Example 2 at the same aluminium concentration.
Comparative E~ample A 50~ W/w solution of a Reheis aluminium chlorhydrate ha~ing an Al/Cl molar ratio of i.91 and a water content of 18.8%
was prepared and heated to 120C in 25 ml Pyre~ glass screw cap tubes, equipped with polytetra~luoroethylene washers, in a ~an oven for 24 hours~ The resulting solu-tion contained 0% of the aluminiu~ in polymers e~ceeding iO0 ~ in effective cliameter.
When tested for antiperspirancy as a 10~/o W/w solution according to ~est Method IV, on a panel of 46 subjects, this solutio~ gave 2% increase in the sweat collected compared to an untreated solution o~ aluminium chlorhydrate of the sa~le concentration.
This result was not statistically signific~nt at the 5% level.
~he following Ex~mples 15 to 25 are of various ~ormulations which may be made ~ro~ the treated basic aluminium compounds described in`-the preceding Examples 1 to 14. Percentages are by weight. For the sake of simplicity the treated aluminium antiperspirant in powder and solution form are referred to herein as "trea-ted powder'l and "treated solution", respectively.
Examples 15 to 20 are of powder aerosol spray compositions o~ the suspension type which are employed with an aerosol applicator.

- 3~ -3~
J.~17'5 EX~E~
o/o Treated powder 3.50 Isopropyl myristate 3.50 Aerosil 200 (pyrogenic silica) 0.10 PerYume 0-44 Propel:lanti q.s. iOO.OO
1 CCl3F: acl2F2 65:35 by weight ~reated powder 4.50 Isopropyl myristate 6.00 Aerosil 200 (pyrogenic silioa) 0,45 Perfume 0~44 Propellan.t~ q.s. iO0.00 1 Propellant CCl3F:CCl2F~ 50:50 by weight Examele 17 - '.

Treated powder 3.50 Isopropyl myristate 8.00 Bentone~38 (hydrophobiG clay) 0.60 Ethyl alcohol (95%~ 0.27 Per~ume 0~40 Propellant q.s. 100.00 1 Propellant CCl3F:CC12F~:CClF2-CClF2:n-butane 20:~0:50:20 by weight ~ -rr~e /~I~J^k - 35 - /, . . ~ .

J.47 Exa~
.__ Treated powder 3.50 Dibutyl phthalate 8.00 Stearoyl monoethanolamicle0.60 Perfume 0.40 Propellant qOsO iO0.00 Propellant CCl3F:CCl2F2:butane 40:30:30 by weight Example 19 ' ~o 'rreated powder 4.00 Isopropyl myristate 6.00 Methylene chloride 25.00 ~ l trichloroethane 5.~0 Aerosil 200 (pyrogenic silica~ 0.4$
Butane 40 59~55 Example 20 ~; yO
'rreated powder 4.00 Bentone 38 (hydrophobic clay) 0.40 Isopropyl myristate 6~00 Per~ume 0,50 P:ropellant 142b 89.10 E~ample 21 __ ~he ~ollowing i9 an example of an antiperspirant lotion ~uitable for use with a roll-on applicator~
;

., - 36 ~

a3~
J.~75 ,~0 Treated polYder 5.00 Urea 5.00 Ethanol 50.00 ~ater 35.00 Tween ~ 0 (polyoxyethylene S.00 sorbitan monooleate) Example a2 The following is an example of an antiperspirant lotion suitable for use with a roll-o~ applicator.

~reated solution (i2.5~) 80.00 Glyceryl monostearate (Arlacel 165) 10.00 Distilled water 10.00 lS Example 23 The ~ollowing is an example o~ an antiperspirant lotion suitable for use with a roll-on or pump ~pray applicator.

Treated powder 12.50 Ethanol 30.00 Glycine 5.00 ~ween 20 (polyoxyethylene 2.50 sorbitan monolaurate) Water 50 00 2S Example 24 The following is an example of a formula ~or a composition in the iorm o~` a stick for use ~ith a stick applica-tor.

- 37 - ~Ø

~5~3~ J,475 Treated po~der 20.00 Volatile silicone 7158~48.00 (Union Carbide) Span ~5 ~sorbitan trioleate) 2.00 Ceto-stearyl alcohol 30.00 1 Decamethylcyclopentasiloxane Example 25 The following i9 an example o~ an antiperspirant cream composition.
%

Treated s olut ion (17 ~`5C/o ) 85 . 7 Glyceryl monosteara-te (Arlacel 165) 10.00 Water 4.30 ~r~c~ k -- 38 -- ***

Claims (23)

J.475 (CA) THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. Process for making a highly effective antiperspirant active compound, in the form of an aqueous liquid or a hydrated powder, consisting of a basic -aluminium compound which is an aluminium chloride, bromide, iodide or nitrate having an aluminium to chloride, bromide, iodide or nitrate molar ratio of from 6.5 to 1.3:1, characterised by the steps of producing said basic aluminium compound in the form of an aqueous liquid containing polymeric species of a size greater than 100 Angstroms within which species there is contained 2% to 80 of the total aluminium, the aqueous liquid having an elevated temperature of up to 140°C. and comprising said basic aluminium compound in solution at a concentration of 7% to 35% by weight, and cooling the aqueous liquid to ambient temperature and/or drying the aqueous liquid to give the basic aluminium compound in the form of a hydrated powder.

2. Process as claimed in Claim 1, characterised by forming an aqueous solution of a basic aluminium chloride, bromide, iodide or nitrate, having an aluminium to chloride, bromide, iodide or nitrate ratio of from 6.5 to 1.3:1 and containing no polymeric species of a size greater than 100 Angstroms, said solution having a concentration of 7% to 35% by weight; and heating the said solution at an elevated temperature of up to 140°C. for a time sufficient to give rise to polymeric species of a size greater than 100 Angstroms within which is contained 2% to 80% of the aluminium.

3. Process as claimed in Claim 1 wherein the said polymeric species greater than 100 Angstroms contain 5% to 60% of the total aluminium.

4. Process as claimed in Claim 2, wherein the said polymeric species greater than 100 Angstroms contain 5% to 60% of the total aluminium.

5. Process as claimed in any of Claims 2 to 4 wherein the said elevated temperature is in the range B0°C.
to 140°C.

6. Process as claimed in any of Claims 1 to 3 wherein the antiperspirant product has the empirical formula A12(OH)6 aXa where X is C1, Br, I or NO3 a is from 0.4 to 1.5 the formula in the case of the compound in solid form containing 0.5 to 8 molecules of water of hydration.

7. Process as claimed in any of Claims 1 to 3 wherein the basic aluminium compound has an aluminium to chloride, bromide, iodide or nitrate molar ratio of from 4 to 1.6:1.

8. Method of inhibiting perspiration comprising applying to the skin an antiperspirant active compound made by the process claimed in any of Claims 1 to 3.

9. An antiperspirant composition comprising an aqueous solution of an antiperspirant active compound made by the process claimed in Claim 1 in combination with an adjunct which is a perfume, thickener, alcohol or propellant.

10. An antiperspirant composition as claimed in Claim 9 in the form of a lotion comprising an aqueous or aqueous alcoholic solution of the basic aluminium compound in a concentration of from 1 to 30% by weight and 0.1 to 5% by weight of a thickening agent.

11. An antiperspirant composition as claimed in Claim 9 comprising an aqueous or aqueous alcoholic solution of the basic aluminium compound in a concentration of from 1 to 30 by weight and from 0.1 to 1% by weight of perfume.

12. An antipersplrant composition as claimed in Claim 9 comprising an aqueous alcoholic solution o the `basic aluminum compound containing from 1 to 60% by weight o an alcohol.

13. An antiperspirant composition as claimed in Claim 9 comprising from 1 to 80% by weight of a propellant.

14. An antperspirant composition in combination,a powdered antiparspirant active compound made by the process claimed in Claim 1 and a powdered inert solid diluent or organic liquid carrier.

15. An antiperspirant composition as claimed in Claim 14 in the form of a powder aerosol composition comprising a suspension o the basic aluminium compound in particulate form in a liquid carrier, said composition also comprising a propellant.

16. An antiperspirant composition as claimed in Claim 15 in the form of a powder aerosol composition comprising A. from about 1% to about 12% by weight of said basic aluminium compound in powder form;
B. from about 0.1% to about 5% by weight of a suspending agent;
C. from about 1% to about 15% by weight of a carrier liquid; and D. from about 70% to about 96% by weight of a propellant.

17. An antiperspirant composition as claimed in Claim 14 comprising from 5 to 40% by weight of said basic aluminium compound in powder form, the remainder consisting essentially of an inert powder material.

18. A solid antiperspirant compound consisting of a spray-dried powder of a hydrated basic aluminium chloride, bromide, iodide or nitrate made by the process claimed in Claim 1.

19. A solid antiperspirant compound as claimed in Claim 18 having the empirical formula A12(OH)6-a aXanH2O
where X is C1, Br, I or NO3 a is from 0.3 to 1.5 n is from 0.5 to 8.

20. A compound as claimed in Claim 19, wherein a is from 0.5 to 1.5.

21. A compound as claimed in Claim 19, wherein a is from 0.8 to 1.25. .

22. A compound as claimed in Claim 19, Claim 20 or Claim 21 wherein n is from 0.5 to 4.

23. A solid compound as claimed in Claim 18, Claim 19 or Claim 20 in the form of particles having size less than 100 microns.