Note: Descriptions are shown in the official language in which they were submitted.
2 i 9 7 4 4 4 p~~gg5~p9100
WO 96104884
LOW PROPELLANT AEROSOL ANTIPERSPIRANT COMPOSITION
Technical Field
This invention relates generally to an antiperspirant aerosol composition
delivered to
the skin of a person through use of an aerosol delivery system. In particular,
the invention
relates to an antiperspirant composition of the powder suspension type
suitable for spraying
from a pressurized aerosol container.
to BackiTround of the Invention _
Antiperspirant--compositions normally contain an astringent, such as aluminum
chlorhydrate, which chemically suppresses the production of perspiration by
sweat glands.
This astringent is commonly applied to the skin in the form of an aerosol
spray.
The antiperspirant active compound is suspended as a dry, impalpable powder in
a
liquid vehicle together with a non-aqueous liquefied volatile propellant in a
pressurized
aerosol container. The aerosol spray is produced by rapid boiling of the
propellant as it
dispenses from the atomizing valve of the aerosol container.
The aerosol method of application has gained wide acceptance for a number of
reasons. Aerosol application of an antiperspirant salt in the form of a powder
suspended in
2o the propellant is cosmetically desirable because the antiperspirant can be
smoothly and
effectively applied to the skin in a manner that is perceived by the consumer
to be a drier and
more comfortable form of application than roll-ons, creams and gels.
Furthermore, because
the antiperspirant powder does not dissolve in the liquefied propellant
medium, the
antiperspirant salt cannot corrode ordinary metal aerosol cans.
One difficulty associated with antiperspirant aerosol sprays is that the
delivery of
small particles of antiperspirant active compound in a spray can readily clog
small valve
orifices. When a residue of the liquid propellantlaerosol composition mixture
remains in the
valve passages following a squirt, evaporation of the liquid may lead to
deposition of solid
material and consequent valve clogging.
so Another problem associated with conventional antiperspirant aerosol sprays
is that
they utilize a large amount of propellant gas. However, an aerosol composition
having a
high proportion of propellant is undesirable. Fluorocarbon propellants are
believed to
accumulate in the stratosphere, where they interfere with the protective ozone
layer. In
addition to contributing to air pollution, hydrocarbon propellants are
flammable, requiring
that the proportion of hydrocarbons be restricted to avoid a fire hazard. When
dispensed the
CA 02197444 1999-12-06
2
Conventional aerosol antiperspirants provide a gassy cloud of particles.
An aspect of the invention is; to reduce the amount of liquid propellant in an
antiperspirant
aerosol composition without causing; clogging of the valve of the aerosol
container.
A need for an aerosol antiperspirant which provides for less cloud/gassiness
exists.
Further a need for a drier feeling application exists. Consumers are also
concerned with value and
the impact products have on the environment.
The present invention relaters to an aerosol composition which meets these
needs. The
present invention is an aerosol composition which provides for a higher ratio
of aerosol
concentrate to propellant allowing for better value since one is paying for
less gas, a drier feel,
less cloud, and compact packaging; which is about half the size of
conventional packaging
allowing for easier handlin;~ and less waste.
All percentages and ratios given are on a weight basis unless otherwise
indicated.
~~ummary of the Invention
The present invention relates to an aerosol antiperspirant composition
comprising:
1) an aerosol concentrate comprising:
a) from about 10°ro to about 35% by total composition weight
antiperspirant
active;
b) from about 15% to about 55% by total composition weight liquid carrier;
c) from about 0.05'% to about 3% by total composition weight suspending agent;
and
2) from about 20% to about 50% by total composition weight propellant;
wherein said aero;~ol concentrate has a viscosity of from about 10 to about
10,000
centipoises; and
wherein the weight ratio is of aerosol concentrate to propellant is from about
1 to 1 to
about 2.3 to 1.
The present invention, in another aspect, relates to an aerosol antiperspirant
composition
comprising:
1 ) an aerosol .concentrate comprising:
a) from about 20°io to about 30% by total composition weight
antiperspirant
active;
b) from about 20% to about 45% by total composition weight liquid carrier;
c) from shout 0.02'% to about 2% by total composition weight suspending agent;
and
CA 02197444 1999-12-06
2a
2) from about 30% to about 50% by total composition weight propellant; wherein
said aerosol concentrate has a viscosity of from about 500 to about 5,000
centipoises; and
wherein the weighl: ratio of s~erosol concentrate to propellant is from about
1 to 1 to about
1.5 to 1.
In this aspect the composition can further comprise an effective amount of an
activator.
In accordance with another aspect of the invention, this invention relates to
an aerosol
antiperspirant composition comprising:
1) an aerosol concentrate comprising:
a) about 25% by total composition weight antiperspirant active;
b) from about :?5% to about 35% by total composition weight liquid carrier;
c) from about 0.05% to about 1 % by total composition weight suspending
agc;nt which is clay;
d) an effective amount of activator which is propylene carbonate; and
2) from about 38% to about 42% by total composition weight propellant which is
isobutene;
wherein said aerosol concentrate has a viscosity of from about 1,000 to about
3,000
centipoises and the weight ratio of aerosol concentrate to propellant is from
about I to I and about
2.3 to 1.
In a preferred embodimem: of this aspect of the invention, weight ratio of
aerosol
concentrate to propellant is from about 1 to 1 to about 1.5 to I.
The composition can further comprise an effective amount of an activator.
Details Of The Invention
Antiperspirant Active
The antiperspirant active comprises any compound having antiperspirant
activity.
Preferably, the antiperspirant materials used include astringent metallic
salts, particularly
including the inorganic and organic salts of aluminum, zirconium and mixtures
thereof. Suitable
antiperspirant aluminum or zirconium salts are any of those well known in the
art, such as those
discussed at length in U.S. Patent Nos. 4,174,386, 4,806,338 and 4,840,786.
Astringent metallic salts are preferred antiperspirant materials for use
herein, particularly
including inorganic and organic salts. of aluminum, zirconium, and zinc, and
CA 02197444 1999-12-06
3
mixtures there~~f Particularly preferred are the aluminum and zirconium salts
such as
aluminum halides, alurru~num hydroxy halides, zirconyl oxide halides, and
zirconvl hvdroxv
halides, and complexes of aluminum. zirconium, and/or zinc with amino acids, a
g., glycines'
Specific. exemplary aluminum salts that can be used include aluminum chloride
and
5 the aluminum hydroxyhalides having the general formula Al~(OH)aQbXH~O where
Q ~;
chloride, bromide, or iodide (preferably chloride); a is from about 2 to abut
5, and
a+b=about 6, and a and b do not need to be integers; and where X is from about
1 to about
6, and X does not need to be an integer. Particularly preferred are the
aluminum
chlorhydroxide;s referred to as "5/6 basic chlorhydroxide" wherein a is 5 and
" 2/3 basic
io chlorhydroxide" wherein a is 4. Aluminum salts of this type can be prepared
in the manner
described more fully in tJ.S. Pat. No. 3,887,692, Gilman, issued June 3, 1975;
U.S. Pat. No
3,904,741, Jornes and Rubino, issued September 9, 1975; U.S. Pat. No.
4,359,456, Gosling
et al., issued November 16, 1982; and British Patent Specification 2,048.229,
Fitzgerald et
al., published December 10, 198 ~ - Mixtures of
l5 aluminum salts are described in British Patent Specification 1,347,950,
Shin, et al., published
February 27, 1 ~~74,
Preferred compounds include the 5/6 basic alumintun salts of the empirical
formula
Al2(OH)SDt.21~i20; mixtures of A1CI3.6H20 and Al2(OH)SC1.2H20 with aluminum
chloride to aluminum hydroxychloride weight ratios of up to about 0.5; ZAG
type
2o complexes wherein the zirconium salt' is Zr0(OH)C1.3H20, the aluminum salt
is
Al2(OH)SC1.2H20 or the aforementioned mixtures of A1C13.6H20 and
Al2(OH)SCL2H~0
wherein the total metal to chloride molar ratio in the complex is less than
about 1.25 and the
AI:Zr mote ra~do is about 3.3, and the amino acid is giycine: and the ZAG-type
complexes
wherein s is frr~m about 1.5 to about 1.87 and n is from about 1 to about 7,
the aluminum
zs salt is Al2(OH)~sC1.2H20, and the amino acid is glycine.
The most preferred antiperspirant actives useful in the compositions of the
present
invention one antiperspirant actives with enhanced el~cary due to improved
molecular
distribution. ~~luminutrn chlorhydroxide salts. zircorryl hydroxychloride
salts,-and mixtures
thereof having improved molecular distributions are known, having been
disclosed, for
3o example, in the following documents, all incorporaued by reference herein;
U.S. Pat. No.
4,359,456, Gosling et al., issued November 16, 1982; European Published Patent
Application, 1.83,171, Armour Pharmaceutical Company, published June 4, 1986;
British
Patent Specification 2.048.229, The Gillette Company, published December (0,
1980;
European Published Patent Application 191,628, Unilever PLC, published August
20. 1986.
35 and British Patent Specification 2.144,992. The Gillette Company, published
March Ø
R'O 96104884 x.19 ~ 4 4 ~ pCT/US95109100
4
1985. 4
The improved molecular distribution is determined by the known analysis method
called gel permeation chromatography This analysis method is described for
example, in
several of the above-incorporated patent specifications as well as in European
Published
Patent Application 7,191, Unilever Ltd., published January 23, 1980, the
disclosures of
which are incorporated herein. It is preferred for purposes of the present
invention that the
antiperspirant actives utilized have enhanced efficacy due to improved
molecular distribution
with a ratio of peak 4 to peak 3 greater than about 0.1:1 as determined by gel
permeation
chromatography. This ratio as is recognized by one skilled in the art, relates
to the relative
area under those two peaks as measured by the gel permeation chromatography
analysis
method.
I-Lghly desirable antiperspirant salts for use herein include aluminum
chlorohydrex
(sold under the name Rehydrol~, by Reheis Chemical Company), aluminum
chlorohydrex
PEG, aluminum chlorohydrex PG, aluminum sesquichlorohydrate, aluminum
sesquichlorohydrex PEG, aluminum sesquichlorohydrex PG, and mixtures thereof,
particularly aluminum sesquichlorohydrate.
Aluminum compounds are preferred to the use of zirconium compounds. The
zirconium compounds which may be used in the present invention include both
zirconium
oxy salts and zirconium hydroxy salts, also referred to as the zirconyl salts
and zirconyul
hydroxy salts. These are preferred compounds for use herein and may be
represented by the
following general empirical formula:
Zr0(OI-172_~Bz
wherein z may vary from about 0.9 to about 2 and need not be an integer; n is
the valence of
B; 2-nz is greater than or equal to O; and B may be selected from the group
consisting of
halides (preferably chloride), nitrate, sulfamate, sulfate, and mixtures
thereof. Although only
zirconium compounds are exemplified in this specification, it will be
understood that other
Group IVB metal compounds, including hafruum, could be used in the present
invention.
As with the basic aluminum compounds discussed above, it will be understood
that
the above formula is intended to represent and include compounds having
coordinated
3o andlor bound water in various quantities as well as polymers, mixtures and
complexes of the
above. As will be seen from the above formula, the zirconium hydroxy salts
actually
represent a range of compounds having various amounts of the hydroxy group
varying from
about 2.0 to only slightly greater than 0 groups per molecule.
Several types of antiperspirant complexes utilizing the above antiperspirant
salts are
known in the art. For example, U.S. Pat. No. 4,120,948, Shelton, issued
October 17, 1978
w0 96104884 21 ~ 7 4 4 4 PGT~S95/09100
,
and U.S. Pat. No. 3,792,068, Luedders et al., issued February 12, 1974, both
incorporated
by reference herein, disclose complexes of aluminum, zirconium, and amino
acids such as
glycines. These complexes and other similar complexes and glycine amino acids
are
commonly know as ZAG complexes. ZAG complexes useful herein are identified by
the
5 specification of both the molar ratio of aluminum to zirconium (hereinafter
"AI:Zr" ratio) and
the molar ratio of total metal to chloride (hereinafter "Metal:Cl" ratio). ZAG
complexes
useful herein have an AI:Zr ratio of from about 1.67 to about 12.5 and a
Metal:Cl ratio of
from about 0.73 to about 1.93.
Also useful are the ZAG complexes disclosed in G.P. Patent Application
2,144,992,
io Callaghan et al., published March 20, 1985. These ZAG actives, when
analyzed by high
pressure gel permeation chromatography, exhibit a distribution pattern having
fur or more
successive peaks or "bands" where the height ratio of Banks IV to III is
greater than 2:1.
More preferred are ZAG actives which have a total area under the curve of
bands I
and II of less than about 10%, preferably less than about 5%, more preferably
less than
about 2% and most preferably less than about 1%.
Preferred ZAG complexes can be formed by
(A) co-dissolving in water
(1) one part A12(OH)6_mQm> Wherein Q is an anion selected from the group
consisting of chloride, bromide, and iodide; and m is from about 0.8 to about
2.0;
(2) x parts Zr0(OH)Z_aQanH20, where Q is chloride, bromide, or iodide; a is
from about 1 to about 2; n is from about I to about 8; and x is from about
0.16 to about 1.2;
(3) p parts neutral amino acid selected from the group consisting of glycine,
dl-
tryptophane, dl-(3-phenylalanine, dl-valine, dl-methionine, and (3-alanine,
and
where p is from about 0.06 to about 0.53;
(B) co-drying the resultant mixture to a friable solid; and
(C) reducing the resultant dried inorganic-organic antiperspirant complex to a
particulate form.
so A preferred aluminum compound for preparation of such ZAG type complexes is
aluminum chlorhydroxide of the empirical formula AI2(OH)SC1.2H20. Preferred
zirconium
compounds for preparation is such ZAG-type complexes are zirconyl
hydroxydchloride
having the empirical formula Zr0(OH)CL3H20 and the zirconyl hydroxyhalides of
the
empirical formula Zr0(OH)2_aCl2-nH20 wherein a is from about 1.5 to about I
.87, and n is
s5 from about 1 to about 7. The preferred amino acid for preparing such ZAG-
type complexes
CA 02197444 1999-12-06
6
is alycine of the formula e~H~(HN~)COOH. Salts of such amino acids can also be
employed
in the antiperspurant complexes See L' S. Pat. No. 4.017.599, Rubino, issued
April 12, 1977.
.4 wide ~~ariety of other types of antiperspirant complexes are also known in
the an
For example. U.S. Pat. No. 3.903.258. Siegal, issued September 2, 1975,
discloses a
zirconium alurrunum complex prepared by reacting zirconyl chloride with
aluminum
hydroxide and aluminum chlorhydroxide. U.S. Pat. No. 3.979,510. Rubino, issued
September 7, 1976, discloses an antiperspirant complex formed from certain
aluminum
compounds. certain zirconium compounds, and certain complex aluminum buffers.
U.S. Pat.
to No. 3,981,896, issued September 21, 1976, discloses an antiperspirant
complex prepared
from an aluminum polyol compound, a zirconium compound and an organic buffer.
U. S.
Pat. No. 3,970,748, MCCCa, issued July 20, 1976, discloses an aluminum
chlorhydroxy
glycinate complex of the appropriate general formula [Al2(OI~4Cl][H2CNH2-
COOH].
t 5 The amount of antiperspirant active in the composition according to the
invention
may vary from about 10°~o to about 35%, preferably from about 20% to
about 30% and most
preferably about 25% of the composition.
Liguid Carrier
The antiperspirant active is suspended in a hydrophobic emollient liquid
carrier. The
2o emollient liquid carrier improves initial adhesion of the suspended powders
to the skin, thus
aiding in the capture of the antiperspirant active by the skin as it is
dispensed in spray form.
Also, the carri~x serves as a diluerrt, lubricant or spreading agent to
facilitate uniform
distribution of the antiperspirant material on the skin.
The carrier can comprise volatile silicone fluids, nonvolatile silicone
fluids, volatile
z5 organic 9uids,n~rrvolatile organic fluids firnctionafized silicones and
mixtures thereof.
Suitable volatile silicone fluids may be cyclic or linear. A description of
various
volatile silicone: oils is found in Todd, et al., "Volatile Silicone Fluids
for Cosmetics". 91
Cosmetics and Toiletri~t, 27-32 ( 1976), incorporated by reference herein.
Linear volatile
silicones genendly have viscosities of less than about five centistokes at
25°C., whereas the
3o cyclic silicones have viscosities of less than about 10 centistokes.
In general, the volatile silicone fluid can be any combination of tetramer,
pentamer.
and hexamer, or low viscosity diorgano fluid. Generally, suitable cyclic
volatile silicone
fluids can be represented by the formula:
R'O 96/04884 PCl'IU695I09100
7
R2
Si"
I
R2 n
wherein R2 is a 1 to 3 carbon alkyl group and n is a number from 3 to 10,
preferably form 3
to 7.
Examples of volatile silicone fluids useful in the present invention include,
for
example (a) (i) SF 1202, containing a pentamer in a minimum amount of 95%, and
5% of
other cyclics; (ii) SF 1204, containing 85% of pentamer and 15% of tetramer;
(iii) SF I I73,
containing 95% of tetramer and 5% of other cyclics; all of the foregoing
products being
available from General Electric Company; (b) Dow Corning 344 fluid, wherein R2
is methyl
and wherein the fluid typically comprises by weight about 88% tetramer, about
11.8%
1o pentamer, and traces of trimer and hexamer; and (c) SWS-03314 (sold by SWS
Silicones, a
Division of StaufFer Chemical Company) in which R2 is methyl and which is
substantially all
tetramer. Other suitable volatile silicone fluids are Dow Corning 345 (sold by
Dow Corning
Corporation) and 7207 and 7158 (sold by General Electric Company).
The preferred volatile silicone fluids for use in this invention are the
cyclomethicone
pentamer and the cyclomethicone tetramer. The most preferred volatile silicone
fluid is the
cyclomethicone pentamer.
Examples of suitable volatile organic fluids are linear or branched
isoparafflnic
hydrocarbons having about 6 to about 16 carbon atoms and preferably about 10
to about l4
carbon atoms. The most preferred isoparai~rnic hydrocarbons are those
available from
2o Exxon Corpoiation and having the designation ISOPAR (Registered Trade
Mark).
The term "nonvolatile" means that the liquid will not volatilize during the
time the
composition is on the skin. Thus, the term "nonvolatile" does not exclude
materials that are
slowly volatile and require a long time to evaporate fully, such as the low
viscosity linear
silicones. These are generally polydimethylsiloxanes o~ low viscosity, e.g.,
about 3 to 10
z5 centistokes at 25°C.
Nonvolatile organic liquids such as isopropyl myristate are generally added to
a
dispersion-type aerosol antiperspirant composition to improve adherence of the
astringent
salt to the skin. This type of formulation is described in many patents,
including for
example, U.S. Pat., No. 3,968,203, patented July 6, 1976, to Spitzer et al.;
U.S. Pat. No.
30 3,752,540, patented April 13, 1973, to Wahl; U.S. Pat. No. 3,959,459,
patented May 25,
1976 to Curry.
Suitable examples include fatty acid esters of polyalkyiene glycols wherein
the fatty
acid contains from about two to about 20 carbon atoms, and from about two to
about 200
WO 96104884 219 7 4 4 4 PCTlUS95/09100
8
alkylene glycol units per fatty acid molecule; fatty acid esters of aliphatic
alcohols where the
esters contain from about 12 to about 26 carbon atoms, such as ethyl laurate,
isopropyl '
myristate, isopropyl palmitate, isopropyl behenate, decyl acetate, behenyl
butyrate, hexadecyl
acetate, decyl decanoate, methyl oleate, lauryl laurate, oleyl acetate, and
dioctyladipate.
Among these various liquid carboxylic acid esters, those having from about 12
to 26
carbon atoms are preferred. As described above, they can be either aliphatic
or aromatic and
can contain either one or more ester groups especially preferred for use in
this invention is
isopropyl myristate. Functionalized siloxanes, among those useful herein,
include those of
the following formula:
CHs CH3 CH3 CH3
Xa R-Si0 - SAO Si0 --Si-R-Xa
CH3 CH3 Rt CH3
b X
to
wherein a is 0 or 1, b is from about 50 to about 2,000, and c is from about 0
to about 300; x
is Cl, F, --COOH, or --N(R3)2; R is CH3 (if a = 0) or Rl (if a = 1); Rl is
straight or
branched alkyl containing from 1 to 10 carbon atoms; R2 is H or Rl; R3 is R2
or R1N(R2)2;
and wherein a+c>O and the ratio of (a+c)/(b+c) is from about 0.01 to about
0.30. It is
understood that, in the above formula, the substituted "c" siloxane units may
be interspersed
with the unsubstituted "b" siloxane units. In preferred functionalized
siloxanes of the above
formula, b is from about 200 to about 1200, c is from 1200, c is from about 2
to about 200,
and the ratio of (a+b)/(b+c) is from about 0.01 to about 0.15. Particularly
preferred
functionalized siloxanes are diamine substituted, wherein X is NR2(R1N(R2)2).
zo Molecular weights of preferred functionalized siloxanes useful herein, as
determined
by gel permeation chromatography/low angle laser light scattering (GPC/LALLS),
are from
about 2,000 to about 150,000 preferably from about 20,000 to about 150,000,
more
preferably from about 50,000 to about 150,000. For preferred amino-functional
silicones,
the ratio (a+c)/(b+c) of the above formula, manifested as milliequivalents of
amine per gram
(meq/g) of silicone polymer, preferably is from about 0.01 to about 1.5 meqlg,
more
preferably from about 0.01 to about 0.7 meq/g.
Among the amino-functional silicones useful herein are the following
commercially-
available materials: QZ-8075 and X2-8107, manufactured by Dow Corning
Corporation; Y-
7717 and Y-12035, manufactured by Union Carbide Corporation; 756, 784 and 801,
3o manufactured by SWS Silicones Corporation; GE 176-10977 and GE 179-10979,
manufactured by General Electric Company; and 2181 manufactured by Petratch
Systems,
Inc. Dow Coming Y-12035, GE 176-10977, and 5WS 801 are particularly preferred
amino-
CA 02197444 1999-12-06
9
functional silicone materials usefirl herein Among the other commercialJv-
available
tunctionalized (non-amino) siloxanes useful herein are PS402 carboxy-
substituted siloxane
and PS 183 trifluoro-sub!xituted siloxane (manufactured by Petrarch Systems.
Inc )
Suitable emollient liquid carriers are disclosed in U S. Patents '~los
.t.8==,596 and
5 4,904,463.
In accordance with the preferred embodiments of the present invention, the
emollient
liquid carrier can be a mixture comprising cyclomethicone, dimethicone,
isopropyl palmitate.
isopropyl mvristate, dibutyl phthalate and mixtures thereof. In particular,
the
cyclomethicone used is the cyclic pentamer of dimethyl siloxane having a
molecular weight
to of about 370.
The amount of liquid carrier in the composition according to the invention may
vary
from about I S% to about 5 5%, preferably from about 20% to about 45% and most
preferably from about 2~% to about 35%.
Suspending, Aa~~
t5 In order to prevent caking or settling out of the astringent salt in the
hydrophobic
emollient liquid carrier, a bulking or suspending agent is incorporated in the
composition of
the invention. The suspending agent assists in filling the void space between
suspended
particles.
Clays and silicas can be used as suspending agents. Colloidal silica is
available
zo commercially as CAB-C>~-SIL"' a submicroscopic particulated pytogenic
silica. Silicas are
not preferred for use. If utilized, silica can comprise from about 0.05% to
about 3% of the
composition.
Cliy suspending agents suitable for use are selected from the group consisting
of
montmorillot>it~e cisys and hydtophobically treated montmorilloniu clays.
Montmorillonite
is clays arc those which urntain the mineral montmorillonite and are
characterized by having a
suspending lattice. Examples of these clays include the bentonites,
hectorites, and colloidal
magnesium aluminum silicates. Clay materials are typically made hydrophobic by
treatment
with a cationic surfactant, such as quaternary ammonium cationic surfactants
(e.g., ditallow
dimethyl ammonium chloride, i.e., quaterruum-18).
3o Bentonite is colloidal, hydrated aluminum silicate obtained from
montmorillonite and
has the formula A12034Si02.H20. A more detailed disausion of bentonites can be
found
in the Kirk-Othtner Encyclopedia of Chemical Technology, 2nd eel., Vol 3
(1964), pp 339-
360, published by Interscience Publishers,
Hectoriite, also amontmorillonite clay, differs from bentonite in that there
is almost a
3s complete subs~~itution of aluminum in the lattice structure of bentonite by
magnesium. In
W096J04884 '~ PCTIUS95109100
addition, hectorites contain lithium and fluorine.
The magnesium aluminum silicates are cromplexes of colloidal magnesium
aluminum
silicate richer in magnesium than aluminum.
Preferred clay suspending agents for use in the present invention include
5 hydrophobically treated montmorillonite clays, e.g., hydrophobic bentonites
available under
the trade name of BentoneTM. BentoneT"' is prepared by reacting bentonite in a
cation
exchange system with an amine. Different amines are reacted to obtain a
variety of
Bentones, which may also differ in proportions of Si02, Mg0 and AI204.
Specific
examples ofBentones within the scope of the present invention are Bentone 38,
Bentone 34,
l0 Bentone 27, bentone 14, and Bentone LT, all of which have a particle size
of below about 5
microns and are commercially available from the NL Industries, Inc.
The amount of suspending agent, preferably clay, in the composition of the
invention
may vary from about 0.05% to about 3% , preferably from about 0.2% to about2%
and
most preferably from about 0.5% to about 1%.
The compositions that utilize hydrophobically treated hectorite and bentonite
clays to
suspend the antiperspirant active material will also generally include a clay
activator. Many
such clay activators, as well as the levels of use are known in the art. Such
activating
materials include, for example, propylene carbonate, ethanol, and mixtures
thereof
Typically, the level of the activator will be from about 25% to about 75% of
the weight of
2o the clay, more typically from about 30% to about 50% of the weight of the
clay. The
suspending agents are combined with an activator that enables the hectorite or
bentonite clay
to suspend the antiperspirant active in the hydrophobic liquid carrier. The
preferred
activator is propylene carbonate. The amount of propylene carbonate in the
composition of
the invention is based on the weight ratio of suspending agent to activator of
about I to
about 0.33.
ellant
In accordance with invention, the antiperspirant composition has no more than
50
wt.% of an aerosol propellant. The propellant gas according to the invention
can be any
liquefiable gasknown to the art for use in aerosol containers. Examples of
suitable
3o propellants are trichlorofluoromethane, trichlorotrifluoromethane,
trichlorotetrafluoro- ,
methane, monochlorodifluoromethane, difluoroethane, propane, butane or
isobutane used
singly or in combination.
The amount of propellant in the composition of the invention should be from
about
20% to about 50%, preferably from about 30% to about 50% and most preferably
from
about 38% to about 42%.
V1'O 96!04884 219 7 4 4 4 PCT~S95/09I00
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Optional Components:
c
The compositions of the present composition can also comprise a number of non-
_ emollient optional components to provide cosmetic or aesthetic benefits. For
example,
preservatives, deodorant actives, such as antimicrobials or bactericides,
perfumes, coloring
agents, fillers, dyes and thickeners may be used .
Although not preferred for use, the antiperspirant composition can include
particulate
filler material. A suitable filler material is aluminum starch octenyl
succinsate, which is a
modified corn starch commercially available under the trade name Dry Flo from
National
Starch and Chemical Corporation, Findeme Avenue, P.O. Box 6500, Bridgewater,
New
1o Jersey, 08807. The amount of filler material in the final composition may
vary from 0% to
about 5% preferably less than about .I% and more preferably less than about
0.05% and
most preferably 0% of the total content of particulate material.
In addition, the composition in accordance with the invention can incorporate
allantoin and perfitme. Allantoin is a known stimulator of cell proliferation
and tissue
growth. The addition of allantoin serves to reduce irritation caused to some
sensitive
individuals upon using any aluminum base product and even helps to heal such-
areas of
irritation.
These optional components are chosen so as not to unduly interfere with the
antiperspirant efficacy and the composition stability or other benefits. Such
optional
2o components are generally present in the compositions of the present
invention at a level of
from about 0.01% to about 20%.
MethodofManufacture_ _
The present invention encompasses methods of preparing aerosol antiperspirant
compositions having improved application and cosmetic characteristics. These
compositions
can be made by a variety of well established methods known in the art. A
preferred method
of manufacturing involve dispersing the suspending agent and activator in the
carrier. The
dispersion is stored until it thickens due to swelling of the suspending
agent. The
antiperspirant active is added with mixing. The mixture is then homogenized
such as by
using a Gifford-Wood shearing type homogetuzer until a gel is formed. Thegel
constitutes
3o the antiperspirant concentrate.
It is essential that the antiperspirant concentrate (which comprises the
antiperspirant
active liquid carrier, suspending agent/activator and optional components if
any are utilized)
have a viscosity of from about 10 to about 10,000, preferably from about 500
to about 5000
and most preferably from about 1000 to about 3,000, centipoise. The viscosity
is measured
by Brookfield viscometer 1/2 RVT with a #3 spindle at about 20 rpm
(revolutions per
2197444
R'O 96104884 PC1'lITS95109100
12
minute). The can is pressurized by adding the aerosol propellant and sealing
the package.
EXAMPLE I
An antiperspirant composition of the present invention is prepared as follows:
INGREDIENT - SIGHT
Aluminum Chlorohydrate 24.0
Isobutane 40.0
Cyclomethicone D5 31.4
Dimethicone 350 centipoise1.5
(cps)
Isopropyl Myristate 1.5
Quaterium 18 hectorite 0.75
Fragrance 0.60
Propylene Carbonate 0-2525
100
The concentrate was prepared by mixing the cyclomethicone, dimethicone and
s isopropyl myristate. Then the clay and propylene carbonate are dispersed
into the mixture.
The dispersion is stored for 15 to 20 minutes until it thickens due to the
swelling of the clay
in response to activation by the propylene carbonate. The aluminum
chlorohydrate is added
and mixed. (Fragrance can be added at this point or just prior to the addition
of the
propellant.)
The mixture is homogenized utilizing a Gifford-Wood shearing type homogenizer
until a gel is formed. After the concentrate is homogenized, it has a
viscosity of about 1,500
cps as measured on a Brookfield 1/2 RVT viscometer using spindle #3 at about
20 rpm
(revolutions per minute).
The homogenized concentrate is then combined with the isobutane propellant.
When
the composition is dispensed utilizing a stem orifice of 0.18", a vapor tap
orifice of 0.25", a
dip tube of 0.50" and an actuator orifice of 0.18" the average spray rate is
about 0.25
grams/second calculated by spraying for 10 seconds and averaging the amount
sprayed.
It has been discovered that compositions of the present invention having a
weight
ratio of aerosol concentrate to propellant of from about 1 to 1, to about 2.3
to I and
2o preferably from about 1 to I to about 1.5 to 1 and an aerosol concentrate
viscosity of from ;
about 10 to about 10,000, preferably from abut 500 to about 5,000 and most
preferably from
abut 1,000 to about 3,000 centipoise, achieve significantly reduced spray
rates utilizing
conventional known in the art aerosol valve systems. Thus, less cloud, less
gassiness and
surprisingly a drier feel with equal or superior efficacy can be achieved.
V1'O 96!04884 ~ PCT/US95/09100
13
EXAMPLEII
An antiperspirant concentrate and antiperspirant composition is prepared as
follows:
_INGREDIENT _ _. WEIGHT
Aluminum Chlorohydrate 30.00
Isobutane 40.00
Cyclomethicone DS 23.07
Dimethicone 350 centipoise3.00
Isopropyl Myristate 3.00
Bentone clay 0.25
Fragrance 0.60
Propylene Carbonate 0-O8O8
100.00
Example II is prepared as in Example I. After the concentrate is homogenized,
it has
a viscosity of about 2,500 cps as measured on a Brookfield 1/2 RVT viscometer
using
spindle #3 at about 20 rpm's.
When the composition is dispersed utilizing a stem orifice of about 0.18", a
vapor
top orifice of 0.25", a dip tube of 0.5" and an actuator orifice of 0.18" the
average spray rate
is about 0.25" as calculated in Example I.
EXAMPLE III
1o An antiperspil-ant composition of the present invention is prepared as
follows:
INGREDIENT _. WEIGHT
Aluminum Chlorohydrate 10.00
Isobutane 40.00
Cyclomethicone D5 45.90
Dimethicone 350 centipoise0.50
Isopropyl Myristate 1.00
Quaternium 18 hectorite 1.50
Fragrance 0.60
Propylene Carbonate 0.05
v 100.00
Example III is prepared as in Example I. After the concentrate is homogenized,
it
has a viscosity of about 500 cps as measured on a Brookfield 1/2 RVT
viscometer using
spindle #3 at about 20 rpm's.
When the composition is dispensed utilizing a stem orifice of about 0.18", a
vapor
tap orifice of about 0.25", a dip tube of about 0.5" on an actuator orifice of
about 0.18", the
WO 96104884 219 7 4 ~ 4 PCTIU595/09100
14
spray rate is about 0.25" as calculated in Example I.
The preferred embodiments have been described in detail herein above for the
purpose of illustration only. It will be apparent to a practitioner of
ordinary skill in the art of
aerosol antiperspirant formulations that various modifications could be made
to the above- '
3 described formulas without departing from the spirit and scope of the
invention as defined in
the claims set forth hereinafter.
i
