Note: Descriptions are shown in the official language in which they were submitted.
~'S ~ q9 J.494 (CA)
~ his invention relates to materials having antiperspirant
activity, more especially to processes for their production.
~ or inhibiting perspiration, the application to the skin
of many different antiperspirant active compounds has been
described in the li-terature. However, those compounds most
widely used in commercial products at the present time are basic
aluminium halides, especially aluminium chlorhydrate, which has
an Al/Cl molar ratio of about 2. These active compounds are
applied to the skin from a variety 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 ingredient of various liquid, cream,
stick or dry powder antiperspirant compositions~ However, in
spite of the popularity of al~minium chlorhydrate the presently
available products are capable of producing only limited
reduction in perspiration.
In copending Canadian application ~o. 269 656 there
is described an improved antiperspirant active compound
which comprises a basic aluminium chloride, bromide, iodide
and nitrate having an aluminium to chloride, bromide, iodide
or nitrate molar ratio of from 6.5 to 1.3:1, and which
compound forms in water a solution containing polymeric
species of a size grea-ter than 100 Angstroms within which species
there is contained at least 2/o by weight of -the total aluminium.
Since in aqueous solutions of the basic aluminium compounds the
halide or nitrate is in ionic form the polymeric species present
are hydroxy-aluminium species. ~he antiperspirant active
-- 2 --
,. . :
; !
'5~3~
J.~94
compound may be employed in tbe form of an aqueous solution or
the solution may be spray dried to give a hydrated compound of
the empirical formula
Al2(OH)6_aXa-nH20
where X is Cl, Br9 I or N03
_ is from about 0.3 to 1.5
_ is from about 0.5 to 8.
As described in said copending application these special
forms 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 of the total aluminium is
contained~ may be prepared by heating aqueous solutions of basic
aluminium compounds at elevated temperature. ~he production of
the desired species depends on the appropriate choice of the
reaction conditions which are interrelated. It is preferred to
use temperatures of from 80C to 140C. The period of heating
may be shorter as higher temperatures are used~ ranging for
example from 0.5 hour to 30 days. Of importance is the
concentration of the basic aluminium compound starting material.
The rate of production of the higher polymeric species of the
basic aluminium compound decreases as the concentration of the
solution is increased and at the above temperatures the
concentration should be no more than about 35% by weight.
The present invention in one aspect relates to an
improvement in the above-described process.
'
J.494
We haYe discovered that the presence of an amino acid,
preferably glycine, in the aqueous solution of the basic
aluminium compound increases the rate at which the species
having a size above 100 Angstroms are formed. ~y including an
amino acid in the reaction mixture either at the commencement
or during the reaction one can produce the desired polymeric
species from starting solutions of higher concentration and/or
produce a given amount of the polymeric species in a shorter
time and/or at a lower temperature.
The process of the present invention comprises heating an
aqueous solution of a mixture of a basic aluminium chloride,
bromide9 iodide or nitrate having an aluminium to chloride,
bromide, iodide or nitrate molar ratio of 6.5 to 1.3:1 and an
amino acid, the concentration of the basic aluminium compound
in such solution and the temperature and time of heating the
solution being such that there is produced in the solution
polymeric speeies having a size greater than 100 Angstroms,
said species being produced in such amount that 2 to 80% by
weight of the total aluminium is contained within such species.
The amino acid, whieh preferably contains 2 to 10 earbon
atoms, may be a neutral amino aeid by which is meant an amino
aeid eontaining an equal number of unneutralised amino and
aeidie groups. Examples of neutral amino aeids are glyeine,
alanine, phenylalanine, valine, sareosine, leueine and lysine
hydroehloride. ~owever, other amino aeids may be used, for
example arginine, ornithine and lysine whieh are basie amino
aeids, that it amino acids which contain more unneutralised
amino than aeidie groups.
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J.494
The amount of the amino acid is preferably such that the
aluminium to amino acid molar ratio is from 20:1 to 1:1.
The basic aluminium compound in the solution subjected to
the heat treatment preferably has an aluminium to chloride,
bromide, iodide or nitrate molar ratio of from 4 to i.3:1, more
particularly 2.5 to 1.6:1.
The weight of the aluminium in the species having an
effective diameter above 100 ~ngstroms is preferably 5 to 60%.
The production of the desired species-depends on the
appropriate choice of the reaction conditions which are inter-
related. It is preferred to use temperatures of from 80C to
140C. The period of heating may be shorter as higher
temperatures are used, ranging for example from 0.5 hour to 30
days. Of importance is the concentration of the basic aluminium
compound. As higher concentrations are used (other conditions
being constant) the rate of production of the species having an
effective diameter greater than 100 Angstroms decreases.
Eowever, by the inclusion of an amino acid in the reaction
mixture in accordance with the invention, the rate of reaction,
for a given temperature, is increased. Thus in the process of
. .
the invention higher concentrations can be used to obtain a given
amount of the desired polymeric species in a given time. In
particular, substantial amounts of the polymeric species have
been obtained at 120C from solutions of aluminium chlorhydrate
of a concentration of 40% and even higher concentrations. The
concentration of the solution of the basic aluminium compound
will usually be at least 5%. Under appropriate conditions,
solutions of concentration up to 60% can be used.
-- 5 -- /- . -
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,~.. . .
~5~9
J.494
The conditions of heat treatment described above have beenfound to give rise to the improved basic aluminium compound in
amorphous form, and in particu]ar the formation of boehmite, as
determined by X-ray diffraction, has not been observed. The
production of a substantial amount of boehmite or other crystal-
line forms of alumina would be considered to be disadvantageous.
The aqueous solution of the more active antiperspirant
compound comprising the higher polymeric species as defined, and
produced by the process of the invention, may, if desired~ be
evaporated to concentrate the solution or it may be dried to give
a solid hydrated material. As with untreated aluminium chlor-
hydrate~ for example, drying conditions which lead to both the
loss of water of condensation and hydrochloric acid should be
avoided as these may lead to irreversible degradation of the
i5 treated basic aluminium compound. Any suitable method of drying
may be used~ spray drying being a particularly useful method.
The spray drying method described in US Patent No.3,887,692 may
be employed. The solld material may be ground or milled as
required~ more particularly to a particle size below 100 microns
such that the particulate compound is suitable for use in an
aerosol powder spray product. Drying should be effected in such
manner as to give a product having a water content consistent
with the following empirical formula
12(OH)6_aXanH20.(Amino acid)m
25 where X is Cl, Br~ I or N03~ _ is from about 0.3 to 1.5~ n is
from about 0.5 to 8~ preferably 0.5 to 4~ and m indicates the
amount of amino acid added and is preferably about 0.1 to 2.
- 6 - /
'
~35~39 J.~94
The invention in another aspect also relates to these novel
solid antiperspirant active complex materials.
The antiperspirant agent produced by the process of the
invention may be employed directly as an antiperspirant
composition in the form of the solution, or it may be used
in antiperspirant compositions in the form of a powder obtained
from such solution, or again as a solution obtained from such
powder. Various examples of suitable antiperspirant compositions
are described in the copending application referred
to above.
Thus in accordance with one aspect of the invention there
is provided an antiperspirant composition comprising an aqueous
solution of an antiperspirant active material produced by the
process of the invention in combination with an adjunct which
is a perfume, thickener, alcohol or propellant. ~he anti-
perspirant composition may be 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. Suitable thickening
agents for antiperspirant lotions are well known to those
skilled in the art, and include for example, magnesium aluminium
silicates. ~hickening may also be effected by emulsifying an
oil or the like in the composition. Furthermore9 the
composition may comprise an aqueous or aqueous alcoholic
solution of the basic aluminium compound in a concentration of
from 1 to 30% by weight 9 the amino acid and from ~.1 to 2% by
weight of parfume.
- 7 _
~5~9 J.~94
Tbe composition may comprise an aqueous alcoholic solution
of the basic aluminium compound and amino acid containing from
up to 75% by weight of a C1-C3 aliphatic alcohol. These aqueous
alcoholic compositions preferably contain ethanol, propanol, iso-
5 propanol or a mixture thereof as the alcohol. ~ntiperspirantcompositions comprising an aqueous solution of the basic alumin-
ium compound and the amino acid may contain from about 1 to 80%
by weight of a propellant.
The antiperspirant composition may also comprise in combina-
tion a powdered antiperspirant active material obtained by drying
a solution obtained by the process of the invention and a powder-
ed inert solid diluent or organic liquid carrier. The composi-
tion may be in the form of a powder aerosol composition comprising
a suspension of the basic aluminium compound/amino acid complex
15 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% by weight of said basic
aluminium compound/amino acid comple~ 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.
.
i- 8 - /
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.
~ 5~ J.~94
The carrier liquid may for example be a non-volatile non-
hygroscopic liquid as suggested in US Patent No.3,968~203.
Especially useful are carrier liquids which have emollient
properties and a number of these are referred to in British
Patent Specification No.19393,860. Especially preferred are
fatty acid esters such as isopropyl myristate and those esters
referred to in British Patent Specification No.19353,914 such
as dibutyl phthalate and diisopropyl adipate.
Various other carrier liquids for powder suspension
aerosols are suggested in US Patent Specifications Nos.
39833,721, 3,833,720, 3,920,807, 3,949,066 and 3,974,270 and
in British Patent Specifications Nos.19341,748, 1,300,260,
1,369,872 and 1,411,547. Volatlle carrier liquids may also
be used such as ethanol or a volatile silicone as described in
15 South African and British Patent Specifications Nos.75/3576 and
1,467~676, respectively.
The ratio of total solids in the compositions to the carrier
liquid may vary over a wide range9 for example from 0.1 to 3
parts of the powder per part by weight of the carrier liquid.
2~ 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 trichlorofluoromethane, dichloro-
difluoromethane, dichlorotetrafluoroethane, monochlorodifluoro-
methane, trichlorotrifluoroethane, propane, butane, 1,1 difluoro-
ethane, 1,1 difluoro-1-chloroethane~ dichloromonofluoromethane,
methylene chloride, isopentane and isobutane, used singly or
''' ' ' .
9 _ /
:
~ 5~`9 tJ.494
admixed. Trichlorofluoromethane, dichlorodifluoromethane,
dichlorotetrafluoroethane, and isobutane, used singly or admixed,
are preferred.
Examples of materials that are suitable for use as
permanent gas propellants are nitrogen, carbon dioxide and
nitrous oxide.
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. The materials prevent compacting
of the powder and they may also act as thickening or gelling
agents for the liquid vehicle. Especially preferred are
hydrophobic clays and colloidal silicas. Hydrophobic clays
are available under the trade name Bentone, eg Bentone 34 or
Bentone 38, and their use as suspending agents are describcd in
a number of patent specifications including US Patent
Specification No.3,773,683. Suitable colloidal silicas
L~ include Aerosil 200 and Cab-0-Sil M-5 as well as other grades.
The antiperspirant composition may simply comprise from
5 to 40% by weight of the amino acid-containing aluminium
compound in powder form, the remainder consisting essentially
of an inert powder material, such as talc or starch, for example.
The invention also relates to packages consisting of the
combination of an antiperspirant composition comprising an
antiperspirant active agent produced by the process of the
invention and an applicator for applying the antiperspirant
composition to the skin. The package may be one in which tbe
applicator is a container fitted with a valve for dispensing
~ c~e~< ~e-S t~e
-- 10 --
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. ~
~ J.494
liquid in aerosol form and -the antiperspira~t composition
comprises a suspension of said antiperspirant active agent
in particulate form in a liquid carrier which may be in
admixture with a propellant. Furthermore, the package may be
one wherein the applicator is a container fitted with a valve
for dispensing liquid in aerosol form and the antiperspirant
composition comprises an aqueous or aqueous alcoholic solution
of said antiperspirant active agent. In this case the
aqueous solution may be discharged by a propellant gas or by a
finger-operated pump mechanism or by containing the composition
within a container of pliable material whereby by squeezing the
container the composition is expelled through the spray valve.
~nother form of package is one in which the applicator is a
roll-on applicator and the antiperspirant composition comprises
an aqueous or aqueous alcoholic solution of the said anti-
perspirant active agent. Furthermore, the package may be
one wherein the applicator is an applicator for dispensing a
powdered material and the antiperspirant composition is a
powdered composition including said antiperspirant active
agent in powder form. The applicator may also be a stick
applicator for holding an antiperspirant composition in the form
of a stick or it may be tissue or cloth which is impregnated
with the antiperspirant active material.
The invention also relates to a method of inhibiting the
exudation of perspiration comprising applying the amino acid-
containing polymeric aluminium antiperspirant active material
to the skin.
-- 11 -- / - -
J.494
~5~
Tes_ Method for Assessment of Effic _~ of A tiperspirants
In the Examples given herein a test method is referred to
for the assessment of the efficacy of an antiperspirant active
agent. Details of the test procedure are descri,bed below.
The test method for,the assessment of antiperspirant efficacy
depended on subjecting human volunteers to thermal stress and
gravimetric determination of axillar sweat.
Tes _~Iet_od
Subjects A panel of up to'54 women who use no
- 10 antiperspirant for the 14 days before
the test.
Hot Room ' T,emperat,ure 37C - 1C, relative
humidity approximately 35%.
-
Test Product 10% solution of treated aluminium
chlorhydrate (unless stated otherwise)
~ in water.
Control Product 10~ solution of untreated aluminium
chlorhydrate (unless stated otherwise)
in water.
20 Product Application Approximately 0.5 g of solution was
applied to each axilla with a pump-
spray applicator.
.~
- 12 -
. . .
.. . . .
, ~
~5~9 J.494
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 40
minutes these are removed and rejected.
Sweat ls then collected for two consec-
utive periods of 20 minutes, fresh
tared pads being used for each
collection, and sweat weight determined.
. .~
iO Test Design Subjects attend daily for 3 consecutive
days. They receive one treatment with
the products each day. On the third
day the treatment is immediately
followed by a hot room sitting and
sweat collection.
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 collected
from the axillae treated with each
- product.
% reduction = 100 (C
- 13 -
J.494
~ ~5~q~
where C is -the geometric mean sweat
weight ~rom the axillae treated with
the control product and T is the
geometric mean sweat weight from the
axillae treated with the test product.
The C/o reduction is usually calculated
for each day separately and for the
entire test.
. .
Significance is calculated by applying
- 10 Student's T-test to the logarithmically
___ transformed weights.
Determination of Percentage Aluminium in Polymeric
Species havin a size ~reater than iO0 An~stroms
The 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
spherlcal porous silica beads of particle size 75-125 microns,
and of surface area 350-500 m /g, and having a magimum pore
size of 100 Angstroms. The silica employed, available
B 20 commercially as Porasil A~, had been deactivated to eliminate
adsorption in molecular size separations. The use of Porasil
silica beads as a column packing in chromatography is referred
to in "Gel Permeation Chromatography" by K.H. Altgelt and
L. Segan, i971, pages 16 to 1~. The silica was conditioned
before use by passage of a single large sample (eg ~.5 ml of
a 2% W/w solution) of a heat-treated aluminium chlorhydrate.
Samples to be tested were dissolved in deionized water to
- 14 -
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:
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~5~39 J.~94
approximately 0.2 M aluminium and thoroughly dispersed by
treatment (4 minutes) 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 2 M aqueous
hydrochloric acid solution using a peristaltic pump. A
- differential refractive index monitor linked to a pen recorder
was used to detect fractions as they were eluted. These
fractions were collected and analysed for aluminium by atomic
absorption. Complete elution of all aluminium applied in each
sample was checked by direct analysis of another sample of the
same volume. The percentage of the total aluminium which
appeared in the fraction eluted at the void volume of the column
was considered as that deriving from polymeric material of a
size greater than 100 Angstroms in effective diameter. None
of this polymeric material was found in any untreated aluminium
chlorhydrate solutions.
Determination of Water Content of Powdered Materials
The water content of powdered materials was estimated by
thermogravimetric analysis (TGA). On heating to 1,000C,
aluminium cblorhydrate undergoes the following reaction:
A12(E)5Cl(E2)X ~ A1203 + ~IC11` + (X + 2)H2
From a knowledge of Al/Cl ratio of the material (and hence the
empirical weight of the anhydrous Al2(0H)6 aCla) it is possible
to calculate the number of 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 l,000C.
The following equation shows the method of calculation:
:
.
~ 5~ ~ J.494
x _ (~\re~ht of sol]d_before he~ g x 102) Empirical weight
~ Weight of solid after heating of anhydrous
-- 18 ~Al2(OH~G aCla7
5 The percentage of water is given by
1 ,800Y ____
Empirical weight of anhydrous
. Al2(~)6_aCla + 18x
The following Examples illustrate~the invention. Percentages
are by weight.
Example 1
A solution was prepared from 50 g of aluminium chlorhydrate,
having an Al/Cl ratio of 1.91 and a water content of 18.8%~ and
8.9 g of glycine in 500 g of solution to give an Al/glycine
ratio of 4. Samples of this solution were heated in 20 ml
Pyrex glass screw cap tubes equipped with polytetrafluoroethylene
washers to 120C over 2 hours and maintained at this temperature
for a further 3 ~ours. The resulting,solution contained 20.2%
of the aluminium as polymeric species exceeding iO0 Angstroms
in effective diameter. When tested for antiperspirancy by
the method described herein~ employing a panel of 22 subjects,
this solution gave a 19% reduction in sweat collected compared
to a 10% solution of untreated aluminium chlorhydrate as control.
This result was significant at the 5% level.
Example 2
A batch of aluminium chlorhydrate having an Al/Cl molar
ratio of 2.04 and a water content of 18.5% was dissolved in
deionised water to give a 10% solution. Aliquots of this
solution were taken, to which varying amounts of glycine were
added, and the whole heated at 120C for 3 hours. The
: - - ' .
- 16 - /---
.
- ~ :
~s~q9 J.494
percentage aluminium present as polymeric species with
effective diameters in excess of 100 Angstroms is listed as a
function of the amount of glycine present (per 100 g of solution).
Wt glycine (g) /c Al in polymers Al:glycine
__ > 100 ~st _ms molar ratio
19.2
0.75 21.1 10.00
1.87 22.5 4.00
3.75 28.1 2.00
5.62 31.7 1.33
7.50 42.4 1.00
Example 3
Aluminium chlorhydrate (Al:Cl ratio 2.01) was made up as a
10% solution in deionised water. 100 g aliquots of this
solution were taken and heated in Z5 ml Pyrex screw cap tubes
- equipped with polytetrafluoroethylene washers, at 120C, for
times of 0, 1~ 2, 3~ 4 and 5 hours. To each 100 g of these
heated solutions were added 3.75 g glycine and the samples then
returned to the oven at 120C for a further 6, 5, 4, 3, 2 and 1
hours, respectively, giving a total reaction time of 6 hours.
The aluminium:glycine molar ratio of these solutions is 2.
The percentage aluminium found as polymeric material with
effective diameter in excess of 100 Angstroms is listed as a
function of reaction conditions.
- 17 - /
~ J.~94
Heating time with Heating time in % Al in polymers
no glycine added the presence of > 100 ~ngstroms
(hours) ~Iy~ine (hours)_ _ _
0 6 63.8
1 5 53.4
2 4 55.0
3 3 50.8
4 2 46.8
1 49.5-
Example 4
Solutions of aluminium chlorhydrate having an ~l/Cl molar
ratio of 2.00 were made up at concentrations between iO% and
40/0. Each 100 g of these solutions contained 7.5 g glycine,
with corresponding aluminium:glycine molar ratios varying
between 1:1 to.4:1. The solutions were heated at 120C for a
period of 6 hours and the percentage aluminium found as
polymeric species with effective diameters in excess of 100
Angstroms, determined. These results are tabulated along with
data for reactions in which aluminium chlorhydrate is heated
with no glycine present.
- 18 - /.. ,
~`5~q9 J . 494
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Ex~les 5 to 8
A 50~0 w/~ solution of aluminium chlorhydrate having an
Al¦Cl molar ratio of 2.00 was diluted with deionised water to
give a lU% W/w solution. Aliquots of this solution were taken
and quantities of various neutral amino acids were added. The
resulting solutions were heated in 20 ml Pyrex glass tubes,
equipped with screw caps and polytetrafluoroethylene washers,
to 120C over 30 mlnutes and maintained at this temperature for
a further 3 hours. The percentage of aluminium present as
polymeric species with effective diameters greater than 100
Angstroms is listed as a function of the type and amount of
amino acid present.
_ 20 -
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_ 21 -- /- -
~5~qg J.494
Example _ 9 and 10
. A 12.1% W/w solution of a basic aluminium bromide having
an Al~Br molar ratio of 2.00 was prepared. Aliquots of this
solution were taken and quantities of a neutral or basic amino
acid were added. Pyrex glass tubes, equipped with screw caps
and polytetrafluoroethylene washers, to 120C over 30 minutes
and maintained at this temperature for a further 3 hours. ~he
percentage of aluminium present as polymeric species with
effective diameters greater than 100 Angstroms is listed as a
iunction o~ the type and am~unt of amino acid present.
.
_ 22 - / ~
. .
.
.
.
~1~5~' ~ J. 494
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E~x amp 1 e 11
A solution was prepared from 9.34 g of 500,b WJw aluminium
chlorhydrate having an Al/Cl molar ratio of 2.00, 0.76 g of
aluminium chloride hexahydrate and deionised water to give 50 g
of a solution with an Al/Cl molar ratio of 1.50. An aliquot
of this solution was taken and the amino acid added. The
resulting solution was placed in a Pyrex glass tube equipped
with a screw cap and polytetrafluoroethylene washer and heated
to 120C over 30 minutes and maintained at this temperature for
3 hours. The percentage of aluminium present as polymeric
species with effective diameters in excess of 100 ~ngstroms is
listed as a function of the amount of the amino acid present.
- 24 _
.: , .
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J. 494
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