CA1111771A - 3 phase antiperspirant stick - Google Patents

Abstract

ANTIPERSPIRANT STICKS

ABSTRACT OF THE DISCLOSURE

Stable, three-phase antiperspirant stick composi-tions having 1) a solid, shearable antiperspirant phase, 2) a gel phase comprising a polyhydric aliphatic alcohol gelled with soap, and 3) a barrier phase of specified minimum thickness separating the antiperspirant and gel phases comprising a water-insoluble, alcohol-insoluble, high melting point wax and liquid emollient and which is relatively free of particulate materials. Such anti-perspirant sticks provide effective antiperspirant performance as well as desirable application char-acteristics.

Description

7~

BACKGROUND OF_~E INVENTION

1. Field of the Inventi_ .
The present invention relates to antiperspirant ~ :
compositions in the form of solid sticks. The composi-tions herein comprise three phases, one of which i.s an antiperspirant phase contain.ing antiperspirant materials, a second of which is an alcohol gel phase which can contain deodorant materials and a third of wh.ich is a barrier phase isolating and insulating the other two 10 phases from each other. .
.:

-~ ~ , ., ' ' : ~ :
.. ~.

: : :

:

.

~:

, :: ~, . ' .: -.

77~

2. The Prior ~rt ~ntiperspirant compositions in stic~ Eorm are known in the art. Single phase antiperspirant compositions have, for example, been disclosed in Taub; U.S. Pa-tent 1,98~,669;
issued December 18, 1934 and Procter & Gamble; British Patent 1,433,695; granted August 25, 1976. Stick composi-tions of this type typically employ large amounts of waxy materials as the vehicle wilich delivers the antiperspirant active to the skin. The antiperspirant active materials often are present in the stick in particulate form which is particularly effective. Such stick products are stable and are especially effective for delivering large amounts of antiperspirant salts to the skin.
Attempts have been made to realize deodorant and antiperspirant sticks which deliver active ingredients to the skin via a vehicle which glides easily over the skin surface and which imparts a ccoling sensation to the skin both during and after application. Soap/alcohoI gels can ; provide such cosmetic bene~its. However, incorpora-tion~of o conventional astringent antiperspirant sal-ts into such gels tends to interfere with the gel structure and render it less cosmetically desirable. To solve such compatibility problems, soap/alcohol gel sticks have been formulated using .
special additives such as lactate salts. (See, for example~
Teller; U.S. Patent 2,732,327, issued January 24, 1956 and Slater; U.S. Patent 2,900,306, issued ~ugust 18, 1959).
Sorne soa~p/alcohol gel antiperspirant sticks have also been formuIated in two phases with an inner core containing gel-compatiblc antiperspirant salts and an outer shell contain-o ing d~odorant matcrials (S~e Bell, U.S. Patent 2,97Q,083, issu~d Januarv 31, l9Gl).

:, ~ ,............................ i",~., . ~ ~ : :: , . .

7~

Combinations of a conventional waxy antiperspirant compositiQn with a soap/alcohol gel to foxm a two-phase stick composition could enhance composition efficacy and improve composltion cosmetic benefits. Such combination is, however, not made without certain difficulties. While each phase alone of such a stick composition is stable, contact between the two phases can cause destructive inter-action be~ween the two phases. The alcohol/gel phase ex-periences syneresis which is a bleeding or leaking of the gelled alcohol from the gel structure or matrix. Such l~aked alcohol can interact with components of the waxy phase and can thus consume or physically separate the phases, thereby resulting in an unacceptable consumer product.
It is speculated herein that this problem of inter-facial interaction is due to, or at least exacerbated by, the presence of particulate materials in the antiperspirant phase. OEten, the particulate material present in the anti-perspirant phase is the antiperspirant active material it-self. The particulate may be present, however, merely as a filler or inert component. The ability of the barrier phase to effect gel pH is also a factor in product stabllity.
Given the state of the antiperspirant art as described above, there is a continuing need for new and useful antLperSpirant stick compositions which are stable and whlch provide both good antiperspirant efficacy as well as desirable application characteristics. ~ccordin~ly, it is an object of the present invention to provide mulki-phase antiperspixant sticks with effective antiperspirancy performance and desirable application characteristics.

- 3 -'~:
~' .

7~

It is a further ohject of the present inventionto provide multi-phase antiperspirant sticks which are dimensionally stable.
It is a further object of the present invention to provide such multi-phase antiperspirant sticks which do not exhibit severe interfacial interaction.

:
'" `

:: :

:

' , 3a ~ ~ i :~ : ~: : : ~ I

s . :

It is a fur~her object of the prc!.iellt i.nv~rlLion to provide mu].ti-phase antiperspirant stic);s ~ ic:h can deliver both antiperspirant ancl deodoran-t materials to the skin simultaneously.
It has been surprisingly discoverecl that the above objectives can be realized and superior multi-phase anti-perspirant sticks provided by formulati.n~ a stick having a thin waxy barrier of specific composition and ~hich is relatively free of particulate materials and has an appro-priate pH. This third barrier phase prevents inter-facial interaction ~hen present in the region inter- .
jacent to a solid shearable antiperspirant phase which preferably utilizes particular amounts of certain types of waxes, emollients and particulate antiperspirant actives and a gel phase formulated with particular amounts of certain polyhydric alcohols and gel~forming agents.
." , ~ ., .

'O

J
.~

771~

SUMM~RY OF T~IE INVI;~NTION
___ Thc present invention relates to arltipcrspilant compositions in the form of a three-phase stick. Such compositions comprise from about 35~ to 65% by weic3ht of - a shearable, solid antiperspirant phase, from about 35%
to 65% by weight of a gel phase; and an interjacent barrier phase contiguous to both the gel and the antiperspirant phase, which barrier phase comprises from about 1% to 10~ by wei~jh~
o~ the total antiperspirant composition.
The antiperspirant phase of the three-phase stick compositions can be any solid , shearable materiaL which can deliver an astringent antiperspirant active. Pre~er-ably,the antiperspirant phase contains ~rom about 2% to 15% by weight of the antiperspirant phase of a high melt-ing point wax, from about 2~6 to 50~ by weight o~ the anti-perspirant phase of a water-insoluble, liquid, organic :
emollient and from about 15% to 60~ by weight of the antiperspirant phase of particulate astringent antiper-~20 spirant materiaL on an anhydrous basis. The nigh melting point wax utilized in the antiperspirant phase has a melting polnt~between about 150F. and 215F.
The gel phase of the three-phase stick compositions contains from about 10% to 92~ by wei~ht of gel phase of :
~25~ a ~polyhydric alcohol and from about 5%~to~ 15~ by weight of gel phase of a gel forming agent.
The polyhydric alcohol used in the gel phase can be a~polyhydric;aliphatic alcohol having frorn 2 to 3 car~on atoms and 2~or 3 hydroxyl groups~. ~The gel forming ag nt 30~ ~ can~be elther a sodlum or~potasslum~salt of a fatty acid having from 1~ to 18 car~on atoms.

.

l 77~

The barrier pnase of the three-ph~lse sticks nere-in has a thickness oE at le~s-t about 0.005 inch. This barrier phase colnprises from about 10~ to '10~ by t~ ht o~ the barrier phase oE a water-insoluble, alcohol-insolu-ble, high meltin~ point wax ancl from about 20~ to ~040 of a liquid organic emollient~ The barri~r phase should be relatively free of particula-te materials and not be capable of lowering the gel pH below about 9.5.
Preferred emhodiments of the three-phase stick com-!0 positions herein provide the alltiperspirant phase in the form of a core, the barrier phase in the form of a tubular sleeve interjacent, and with the gel phase surrounding the sleeve forming a shell~ Preferred embodiments also include three-phase sticks wherein the gel phase contains a mono-hydric alcohol component to provide a skin cooling sensa-tion and a deodorant material to provide deodorant efficacy.

:.
BRIEF DESCRIPTION OF THE DRA~INGS
~FIGURE 1 is a ~erspective view o~ the preferred embodiment of the present invention with the cosmetic por tion partially extended FIGURE 2 is a cross-section taken on -the line 2-2 of FIGURE 1 with the thickness o the barrier phase exag-gerated for clarity of illustration.
FIGURE 3 is a fragmentary perspective view of ano~her embodiment of the invention.
FIGURE 4 is a p~ain view of yet another embodiment of the invention.
:.

. ' - - , : , .. : - . . . .

7~

DETAILED DESCRIPTION OF THE INVENTION
, . . . ~
The -three-phase antiperspirant s-tick compositions of the present invention comprise A) an antiperspirant phase B) a gel phase and C) an interiacent barrier phase contiyuous to both the antip~rspirant and gel phases. These essential elements as well as optional components composition pre-paration and composition use are discussed in detail as follows:

ANTIPERSPIRANT PHASE
One essential component of the antiperspirant sticks herein is a solid shearable phase. This phase provides the vehlcle for the antiperspirant-ac-tive ingredlent~ Such an antiperspirant phase generally serves to deliver anti-perspirant material(s) to the skin via a medium which does not feel runny~ cold or s-ticky. The antiperspirant phase -component of the stick compositions herein comprises from ~ about~35~to 65~1 preferably from about 45~ to 55~ by weight ; ; of the total~composition. The antiperspirant phase is solid (i.e~ able to retain a rigid form at 20C.) and is 20~ shearable (i.e~. yields easily when rubbed onto the skin in the normal manner of usage of cosmetic sticks.) Many solld antiperspirant compositions are known in the art~which tend to interact with soap~alcohol gels if suoh~antiperspirant compositions are formulated into stick ;products~along with such~;soap~alcohol gels. It has been di~scovered~however~ thàt;such antiperspi~ant ~ompositions~
can be~;combi~ned~with~s~oap/alcohol ~els in the~three-phase ~;
tick~ p~aducts or the pr~ent lnven ion.

X~

77~L

The s~illed artisan can readily ~ormul~te a larc3e number of solid compositions ~hich have antiperspirant cfEec-tiveness and have shearable cosmetics and which are thus suitable for use as the antiperspirant phase of Lhe stick compositions herein.
In an especially preferred embodiment, the antiper-spirant phase is substantially anhydrous, ti.e., comprlses no more than about 1.0~ by weight of the antiperspirant phase in water in addition to the waters of hydration Oll the antiperspixant salt), provides the antiperspirant active in an especially effective undissolved particulate form, and com-prises a water-insoluble wax, a liquid organic emollient and particulate antiperspirant~active material.
Water-Insoluble Wax _ . . .
~ hiyh melting point, water-insoluble wax is the ~ -principal component of the antiperspirant phase in a pre-ferred embodiment of the stick compositions herein. It is believed that the high melting point wax provides a struc-ture which can be sheared during application to the skin, thereby depositing layers of wax and antiperspiran~ active particles onto the skin.
The antiperspirant phase herein contains from about 2~ to 15%, preferably from about 3~ to 11%, by weight o~
antiperspirant phase of the water-insoluble ~lax materials.
Maintenance of wax concentrations within these limits permits ;~ the realization of acceptable stick cosmetic characteris-tics. Furthcrmore, exposure to normal temperature extremes, especially during summer, might deform sticks without high ~ melting point wax concentrations within the limits indicated.
3~

a~
.... . . : ... . . . . .. .. , ~ , . . . - - ~ . - ; : .. . - :
. . . . . . .. . . . . .
.

The ~a~es em~loyed as an essential comr)ollerlt of thc prcferred antiperspirant phaso oE the t:ichs hercill arc cs-sentially water-insoluble (soluhle to arl cxtcnt of less than 0.56 by weight in ~rater at 80F.). Such wa~es have a meltlng point within the range of Erom about 150~. to about 215~., preferably within the range oE from about 170F.
to 210F. Such waxes are referred to as hiyh melting point waxes. Examples of suitable high melting point tla~es are beeswax, carnauba, bayberry, candelilla, montan, ozokerite, 0 ceresin, paraffin, synthetic wax~s such as Fisher-Tropsch waxes, and microcrystalline wax. Preferred high m~lting point waxes are ceresin, ozokeriter white beeswax and syn-thetic waxes~ It is understood that mixtures of the high melt-ing point waxes are acceptable for use in the compositions herein.
LIQUID ORGANIC E:MO:LLIENT
A second essential component of the pref~rred anti-perspirant phase is a liquid organic emollient. This emol-lient component serves to improve the cosmetic acceptability of the compositions herein by helping to impart a soft, supple character to the skin treated with the instant stick compositions.
The emollients used herein can be any non-toxic, organic material or mixtures thexeof which is of low irritation potential, which is liquid at 20C. and which ` ~ is substantially water-insoluble (i.e. water solubility of from about 0.5~ to 1.0~ by weight in water at 20C.).
llowever, thc liquid emollients of -this invention are water-dispersible in the presence of a surfactant, e.g., soap, which ) is desirable in that it permits the removal of the composition ;~ during washing or bathlng. The emollient component comprises ~rom about 20~ to 50%, preferably from about 30~ to 40%, by weight of the antip~rspirant phase~

' ' , .
~ 9 _ 7~

Suitable organic emolllents include Eatty acid and fatty alcohol esters and water insoluble ethers.
Examples of such emollients include isopropyl myris-tate, isopropyl palmitate, cetyl acetate, cetyl propionate, di-n-butyl phthalate, diethyl sebacate, diisopropyl adipa-te ethyl carbomethyl phthalate, and the condensation produc-t of about 14 moles of propylene oxide with one mole of butyl alcohol (Fluid AP ~ . Preferred organic liquid emollients include isopropyl myristate, isopropyl palmitate, di-n-butyl phthalate, and Fluid AP ~ Especially preferred orcJanic emollients include isopropyl myristate, isopropyl palmitate and Fluid AP ~
Suitable emollients for use herein also include both volatile and non-volatile polyorganosiloxane materials.
Useful alcohol-soluble materials of this type can have the , .
chemical structure:

R R R
l I .
R - Si ~ O - Si - O - Si - R

R R X R

or ~ .
, R
: I
R - 5i - R

R O R

R - lI - O - Sl - O - Sl - R

R R R

wherein the R groups can be the same or different and are selected from Cl - C~ alkyl groups and phenyl groups, wherein x equals the number of repeating diorganosiloxy groups and wherein the viscosity of said organopoly-siloxane is from about 9 to about 50 cs at 25C. Examples of such organopolysiloxanes include DC-556 fluid, which is tris (trimethylsiloxy) phenylsilane and DC-225 fluid, a polydimethylsiloxane having a viscosity of 9.5 cs at 2~C., both marketed by Dow Corning Corporation. Preferred poly-siloxane emollients include SWS-03314 marketed by Stauffer Chemical Company and UC-7158 or UC-7207 each marketed by Union Carbide Corporation.
Emollients including the liquid emol]ients suitable for use herein are described more fully in Balsam and Sagarin, Cosmetics Science and Technolo~y, 2nd. Ed., Vol.
1, Wiley-Interscience, 1972, Chapter 2, pp. 27 - 104 and in U.S. Patent 4,045,548, August 30, 1977 to Luedders et al.
Particulate Antiperspirant Material A third essential component of the preferred anti-perspirant phase of the present compositions comprises aparticulate astringent antiperspirant material. Such antiperspirant active material, of course, imparts anti-persp~irancy efEicacy to the antiperspirant stick compositions of the present invention.
Any aluminum astringent antiperspirant salt or alum-inum and/or zirconium astringent complex in particulate form can be employed herein. Such salts and complexes are wéll known in the antiperspirant art. Salts useful as astringent antiperspirant salts or as components of : :
astringent complexes include aluminum halides, aluminum ' :

:: :

7~

hydroxyhalides, zirconyl oxyhalides, zirconyl hydroxy-halides and mixtures of these salt materials.
Aluminum salts of this type include aluminum chloride and the aluminum hydroxyhalides having the general formula A12(0H)xQy.XH20 where Q is chlorine, bromine or iodine;
where x is 2 to 5 and x~y = 6 and x and y do not need to be integers; and where X is about 1 to 6. Aluminum sal-ts of this type can be prepared in the manner described more fully in Gilman, U.S. Patent 3,887,692, issued June 3, 1975.
The zirconium compounds which are useful in the present invention include both the zirconium oxy salts and zircon-ium hydroxy salts, also referred to as the zirconium salts and zirconyl hydroxy salts. These compounds may be represented by the following general empirical formula:
ZrO(OH~2 nzBz wherein z may vary from about O.9 to 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 consist~
; ing~of halides, nitrate, sulfamate, sulfate and mixtures thereof. Although only zirconium compounds are exemplified in this specification, it will be understood that other groups IV B metals, including hafnium could be used in the present invention. -As with the basic aluminum compounds r it will be understood that the above ormula is greatly simplified and is intended to represent and include compounds having coordinated and/or bound water in various quantities, as , well as polymers, mix;tures and complexes of the above As will be seen from the above .

.

formula, the zirconium hydroxy salts actua:Lly represent a range of compounds having various amounts of the hydroxyl group, varying from about 1.1 to only slightly greater than 0 groups per molecule.
Several types of antiperspirant complexes utiliz-ing the above antiperspirant salts are known in the art.
For example, Luedders et ~1; U.S. Patent 3,792,068, issued February 12, 1974 discloses complexes of aluminum, zirconium and amino acids such as glycine~ Complexes such as those disclosed in this Luedders et al '068 patent and other similar complexes are commonly known as ZAG.
ZAG complexes are chemically analy~able for the presence of aluminum, zirconium and chlorine. ZAG comple~es use-ful herein are identified by the specification of both the molar ratio of aluminum to zirconium (hereinafter "Al:Zr"
ratio) and the molar ratio of total metal to chlorine (hereinafter "Metal:Cl" ratio~. ZAG complexes use~ul here-in have an Al:Zr ratio of from about 1.67 to 12.5 and a Metal:Cl ratlo of from about 0.73 to 1.93.
Pref~rred ZAG complexes are 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 a number from ,: ~
about 0.8 to about 2.0 (2) x parts ZrO(OH) 2_aQa.nH2O where Q is chloride, bromide or iodide; where a is from 1 to 2;

, where n is from 1 to 8; and where x has a value of rom about 0.16 to about 1.2;

. .
(3) p parts neutral amino acid selected from the -12a -' I '' 7~7~

group consisting glycine, dl-tryptophane, cll-~-phenylalanille, dl-valine, dl-meth.ionine and ~-alanine, and where p has a value of Erom about 0.06 to about 0.53; ...
(B) Co-drying the resultant mixture to a Eriable solid; and ~C) Reducing the resul~ant dried inorganic-organic antiperspirant complex to particulate fo~m.
The preferred aluminum compound for preparation of such ZAG type complexes i.s aluminum chlorhydroxide of the empirical formula A12(OH)5C1~2EI2O. The preferred zirconium compounds for preparation of such ZAG-type complexes are zirconyl hydroxychloride having the empirical formula , :, .
': ` ' ' .
.

:

:
:
: ' : ~ : : . .
;
: : : ~ ..

~ 13 ~:

~.
:

:~ S~`
r .
~ ' ZrO(0H)Cl.3H20 and the zirconyl hydroxyhalides oE the empirical formula ZrO(0H)2 aCla.nH20 wherein a is from 1.5 to 1.87 and n is from about 1 to 7. The pre-ferred amino acid for preparing such ZAG-type complexes is glycine of the formula CH2(NH2)COOH. tSalts of such amino acids can also be employed in such antiperspirant complexes. See U.S. 4,017,599 to ~.M. Rubino issued April 12, 1977.) A wide variety of other types of antiperspirant complexes are also known in the art. For example, Siegal;
U.S. Patent 3,903,258, issued September 2, 1975 discloses a æirconium aluminum complex prepared by reacting ~
zirconyl chloride with aluminum hydroxide and aluminum : :
chlorhydroxide. . :
Rubino; U.S. Patent 3/979,510, issued September 7, 1976 ~
discloses an antiperspirant complex formed from certain :
aluminum compounds, certain zirconium compounds and certain complex aluminum buffers. Rubino; U.S. Patent 3,981,896j issued September 21, 1976 discloses an ' :

~: '' ~ ' , .
: : :

:

- ~
.

7:~

antiperspirant complex prepared from an aluminum polyol compound, a zirconium compound and an organic bufEer.
Mecca, U.SO Patent 3,970,748, issued July 20, 1976 discloses an aluminum chlorhydroxy glycinate complex of the approximate general formula [A12(0H4)Cl~[H2CNH2COOH].
0f all the above types of antiperspirant actives, preferred compounds include the 5/6 basic aluminum salts of the empirical formula A12(OH)5Cl.2H20; mixtures of AlC13.6H20 and A12(OH)5Cl.2H20 with aluminum chloride to aluminum hydroxychloride weight ratios of up to about 0.5; . .
ZAG type complexes wherein the zirconium salt is ZrO(0H) ;:
Cl.3H20; the aluminum salt is A12(OH)5Cl.2H20; and the amino . .:
acid is glycine and Z~G-type complexes wherein the zircon- . . .
ium salt is ZrO(0H)2 aCla.nH20 with a ranging from about l.S to 1.87 and n ranying from about 1 to 7; the . .
:: aluminum salt is A12~OH)5Cl.2H20; and the amino acid is glycine. .
: The preferred embodiment o~ the antiperspirant phase of the present stick compositions contains from about 11% to ..
20~ 50%, preferably from about 30% to 46%, by weight of the antiperspirant phase of the particulate astringent anti-perspirant material calculated on an anhydrous metal salt :
basis (exclusive of glycine/ the salts of glycine or other ..
complexlng agents). Such particulate antiperspirant materlal is preferably impalpable, ie. has particle sizes : ranging~f:rom about 1 to about 100 microns, more preferably from about 1 to about 50 microns. The antiperspirant : ~ . active material herein is preferably alcohol insolubleO

:

; :: :
~:

Optional Antiperspirant phase components The antiperspirant phase of the instant stick compositions can contain a variety of optional ingredients suitable for improving composition efEicacy, stability~
cosmetlcs and/or aesthetics. Such optional antiperspirant phase components include low melti.ng point waxes to adjust s-tick cosmetics, inert filler material to improve c~omposition stability and cosmetics, perfumes, dyes, coloring agen-ts, preservatives and the like.
A highly preferred cptional component of the preferred antiperspirant phase ls an additional wax material having a melting point of from about 100F. up to 150F.
Such optional waxes are referred to herein as low melting point waxes. The low melting point wax component can be used as an adjunct to the high melting point wax to provide improved emolliency and to enhance the structural integrity of the waxy antiperspirant phase. The low melting point wax can also be used to adjust the feel of the stick compositions herein. One skilled in the art will easily be able to make a product which feels more brittle, soft, slippery, sticky, rough, etc., by blending various suit-able low melting point waxes with the essentially present . . .
:high melting point waxes.
Examples of useful low melting point waxes include ;: fatty acids containing from about 12 to 20 caxbon atoms, fatty alcohols containing from about 12 to 20 carbon atoms, silicone waxes and glycerol monostearate. Especially pre-ferred materials of this type are the C12 to C20 fatty acids and C12 to C20 fatty alcohols. The most pre~erred low meltlng polnt waxes are cetyl alcohol,stearyl alcohol, myristyl alcohol, lauryl alcohol and glycerol monostearate.

- 16 - ~.

~ X . ', .7'~

If present, the low melting polnt wax component, or mixtures thereof, generally comprlses from about ~% to 20%, more preferably from about 5% to 15%, by weight of the antiperspirant phase.
Another preferred optional component Eor possible use in the antiperspirant phase of the stick compositions herein is an inert filler material. Such filler materials also serve to enhance the structural integrity of the antiperspirant phase herein and serve to improve composi-tion cosmetics.
Useful inert particulate filler materials include talc; colloidal silical e.g., Cab-O-Sil~ (Cabot Corp.), a pyrogenic silica having an average particulate diameter between about 0.01 and 0.3 microns as disclosed in British patent 987,301 and British Patent 1,167,173, and finely divided hydrophobic clays such as the reaction product of a clay such as bentonite and dimèthyldistearyl ammonium chloride, such treated clays being marketed under the trade mark 'IBENTONE'' by NL Industries. Such clay materials are described more fully in British Patent 1,167,173 .
If present, the inert particulate filler material generally comprises from about 0.5~ to 5.0% by weight of th~ waxy antipersplrant phase of the present stick compositions.
.
The antiperspirant phase herein can also contain minor amounts i.eO, from about 0.1% to 1.5% by weight of anti-perspirant phase, of conventional additives such as dyes, perfumes, pigments, coloring agents~ etc. In selecting such ingredients only small amounts of hydrophilic : ~ :

' , ' ' ' ' ' , ' ' . . ' .

materials shall be used in addition to the act.ive material.
Preferably, less than a~out 5% of the antiperspirant phase, ln addition to the antiperspirant materials, is soluble in water.

GEL PHASE
The second essential component o:E the antiperspirant sticks of this invention is a gel phase formed from cer-tain polyhydric aliphatic alcohols and cer-tain gel-forming agents. This gel phase comprises from about 35% to 65%, preferably from about 45% to 55~, by weight of the total antiperspirant stick compositions herein. The primary purpose of the gel phase of the sticks herein is to improve the glidability and ease of application of the instant stick compositions onto the skin. Optionally, the gel phase here-in can also act as a carrier for deodorant materials and ~-for materials such as monohydric alcohols which impart a desirable cooling, moist sensation to the skin upon application.

Polyhyd-ric AIiphatic Alcohol ~ One essentlal component of the gel phase of the present antiperspirant stick compositions is a polyhydric .
aliphatic alcohol containing 2 or 3 carbon atoms and from 2 or 3;hydroxyl groups. This polyhydric alcohol or mix-tures thereof is the medium which is "gelled" to form the gel:phase of the stick compositions herein. The polyhydric :~ aliphatic alcohol component of the gel phase comprises rom about l0~ to 92%, preferably from about 15~ to 50~
;: by weight~ of the gel phaseO

I

. . ~ . ... . . . .. . -. . .. . . . . . . . . .

7~L

Suitable polyhyclric alcohols or use il~ t}l~ CJel phasc herein include ethylene cJlycol, r)ropylene c31~col, trimethylene ~lycol, and glycerine~ The most preferred polyol is propylene glycol.

Gel Forming ~qents -The second essential component of the cJel phase of the antiperspirant stick compositions herein is a gel formin3 agent which is added to the polyhydric aliphatic alcohol of the gel phase to form the desired c~el material.
L0 The gel forming agents used herein can be the sodium and potassium salts ~iOe. soaps) of fatty acids contain-ing from about 1~ to 18 carbon atoms. ;~
Gel forming agents generally comprise from about 5~ to 1~% by weight of the gel phase herein, preferably from about 7% to 10~ by weight of the gel phase.
If the gel forming agent concentrations lower than those specified are employed, the gels formed tend to be dimen-sionally unstable and tend to deform at summerti~le temper-atures. If concentrations of gel ~orming agents above those specified are utilized, the gels formed tend to be too hard and do not exhibit desirable ylide and applica-tion characteristicsO By utilizing gel-forming agents of the particular type described and in the concentrations specified, gel phases can be formulated which exhibit 25 ~ structural integrity and which exhibit cosmetically desir~
abl~ application properties.
The fatty acid portion of the soap ~el forminy agents should be essentially pure satura~ed or unsaturated higller fatty acids having a Cl~ to Cl~ bac~bone.

': ~

: .
,: , I t~ _ :~ :

7'7:~

Suitable mixtures of such acids can be employed provided that such mixtures are Eree from significant proportions of other fatty acids of higher or lower chain length which substantially adversely affect or neutralize the desired gel forming effects.
Examples of ~atty acids useful in synthesizing the gel Eorming agents herein include myristic, palmitic, stearic, oleic, linoleic, linolenic, behenic, margaric acids and the mixtures of such acids. Naturally occurring sources of such fatty acids include coconut oil, beef tallow, lanolin, fish oil, beeswax, palm oil,peanut oil, olive oil, cottonseed oil, soybean oil, corn oil, rapeseed oil, rosin acids, and greases. Conventional Eractionation and/or hydrolysis techniques can be ~mployed if necessary to obtain the re~uisite types of fatty acids from such materials~
Preferred fatty acid soap type gel forming agents include sodium stearate r sodlum palmitate, potassium stearate, potassium palmitate and sodium myristate.
The most preferred gel forming agent is sodium stearate.

Optional Gel-Phase Comp n_nts ; , The gel phase oE the instant stick compositions can contain a variety of optional ingredients suitable for~improvlng~compositlon efficacy, stability, cosmetics and/or aesthetlas. Such optional gel phase components include monohydric alcohols to improve composition cos-metlcs, water~in small amounts, deodorant materials, al-aohol~ evaparatlon retardants, and anti-syneresis agents~
perfumes,~dyes, pigments, coloring agents and the like~ 1-20 ~ 1 . .

7~

~ hi~hly prefcrred optiorlal cOmpQIlcrlt of thc (~el phase is a monoh~dric alcohol ~/hich serves t:o lmpart a cosmetically desirahle cooliny sensation to thc skin.
~lonohy(lric alcohols of this type contain one to three carhon atoms. Examples of suitable monohydric alcohols include methanol, ethanol, isopropanol~ and n-proparlo]. Preferred Monohydric alcohols are ethanol and isopropanol.
~hile monohydric alcohols can provide a desirable cosmetic cooling benefit for the antiperspirant s-tic}; compositions herein, 0 inclusion of a monohydric alcohol component can also lead to stick composition instability problems. Monohydric alcohols tend to produce dimensional instability of the gel phase and tend to cause the gel phase to evaporate and thereby become sticky as well as to deteriorate and assume a dried and LS shriveled appearance.
It has been surprisingly discovered that such problems can be minimized and that monohydric alcohols can be success-fully incorporated into the gel phase of the stick comyosi-tions herein provided certain concentration limi-ts ~or the essential gel phase components are observed. ~lhen monohydric alcohols are employed, it has been found that the weiyht ratio or polyhydric alcohol to gel forminy agent must exceed about ~.45. When polyhydric aliphatic alcohols and gel form-ing agents are present in this ratio, monohydric alcohols can :

' ,, r ~Y 7 ~

be incorporated into the gel phase in a~ounts of f~om about 10~ to 72%, preferably from about 40% to 70~, by weight of the gel phase.
When monohydric alcohols are employed, another highly preferred optional component o~ the gel phase is a material which helps retard alcohol evaporation and which acts as an anti-syneresis agent. Especially pre-~erred materials of this type are cellulose derivatives such as hydroxyalkylcelluloses. Especially preferrPd materials of this type are hydroxypropylcellulose compounds having the chemical formula:

OH
I ' 1 3 ~OCH2C~ICH3 _-_- O \ ~/1 ~ H ~
\~ t/H \~ :~

H f H2 ;

~20 OCH21CHCH3 OH
_ _ :~:
N

and wherein N is sufficiently large such that the total molecular weight of the material ranges from about 60,000 to 1,000,~00O ,Such materials are sold under the tradename of Klucel ~ by Hercul,es Incorporated. I~ present, such alcohol ~,:
- 22 - ~
': :
:
, 7~

evaporation retarding agents and anti-syneresis agents comprise f.rom about 0.1% to 5.0% by weight of the gel phase.

~ ::

:

:

- 22a -:

~: : : ,:
, 7-~ `

Another opti.onal inyredient of the yel phase herein is a conventional deodorant material. Suitabl.e deodorants include bacter:iostatic quate~nary ammonium compounds such as cetyltrimethylammonium bromite, cetyl pyridinium chloride, benzethonium chloride, diisobutyl phenoxy ethoxy ethyl d:i-methyl benzyl ammonium chloride, N-al]cylpyridinium chloride, N-cetyl pyridinium bromide/ sodium N-lauroyl sarcosine, sodium N-palmetoyl sarcosine, lauroyl sarcosine, N-hyristoyl glycine, potassium N-lauroyl sarcosine and stearyl trimethyl ammonium chloride.
If present, deodorants generally comprise from about 0.1~ to 1.0% by weia,ht of -the gel phase.
Conventional optional ingredients such as perfumes, dyes, pigments, coloring agents and the like can also be added to the gel phase. I present such minor additions com-prise from about 0.1% to 1.5% by weigh-~ of the gel phaseO
Small amounts of water can be added to the gel phase.
The amount o water added should, however, be limited to less than about 10%o Water can be used as a solvent for an optional dry material or for an optional deodorant mater.ial.
Water in the gel phase at concentrations exceeding 10% tends to produce a gel phase which is undesirably soft. `~

: ' ' ~ , , .

:

7~

B~RRIER PIIASE
The third essential compone~nt of t~c antiperspirant sticks of this invention is the barrier phase. The barrier phase serves to segregate the ~el phase from the antiper~
spirant phase and thereby effectively eliminates the problem of destructive interfacial interaction. The barrier phase comprises from about 1% to 10%, preferably about 2% to 4 by weight of the total antiperspirant stick compositions herein. To insure that the barrier phase constitutes a con-0 tinuous layer of protection, the barrier phase should have a minimum thickness of at least about .005 of an inch.
Preferably, the barrier phase ranges in thickness from about 0.010 inch to 0O040 inch.
It has been found that when certain formulations of lS the gel ~hase an-' the antipersPirant phase (such a~s the pre-ferred embodiment herein) are in physical contact, a destructive interfacial interaction occurs. This phenomenon of inter-facial interaction involves the alcoholts) escaping from the yel structure and migratinc3 into the antiperspirant `'0 core phase where the emollient is solubilized hy the alcohol~s~-It is speculated that when the gel phase and the chemically dissimilar antiperspirant phases are in juxtaposition then the polyhydric and monohydric alcohols, antiperspirant active~
and emollient concentration gradients create a diffusional :
25~ driving force which causes the polyhydric alcohol to ml~r~te from the gel phase into the antiperspirant phaseO Conversely, the diSsolV~d antiperspirant material and the emollients tend to migrate from the antiperspirant phase înto the gel phase~ The gross effect is an antiperspirant phase plasti-~0 ~ zation and,ultimately~a noticeahle liquid runoff ancl a con~
; ~ committant shrinking of both the gel phase and the ~ antiperspiran~ phase.

: ~ .
-- ?-~ _ - , 77~

The lîquid runoff also tends to undesirably plasticize the an-tiperspiran-t phase. While such theore-tical in-ter-pre-tation does not limit the scope of this invention, it is believed that the particulate an-tiperspirant material in -the antiperspirant phase provides diffusion pathways for -the alcohol of the gel phase to migra-te into the adjacent anti-spirant phase.
It has been surprisinqly discovered -that a thin wax/
emollient barrier in the region interjacen-t to the gel phase and the antiperspirant phase effectively prevents this inter-facial interaction. Such a wax/emollient barrier mus-t be substantially free (i.e. present to an extent of less than 0.01% by weight of the barrier phase) of particulate material (i.e. discreet solid material having a particle size of grea-ter than about one micron). It is speculated tha-t by providing a region of waxy material which is free of the diffusion path-ways provided by particulate materials, -the migratiorl of the alcohol into the antiperspirant phase is efEectively pre-vented. Effectively isolated by the interjacent, alcohol impermeable barrier phase, the gel phase and antiperspirant phase of the three-phase sticks exhibit neyliyible destructive interfacial interaction.
The barrier phase of the compositions herein should also be free of materials capable of lowerin~ the pH of -the ~el phase substantially. The barrier should preferably not contain materials capable of lowering the gel pH in the area of the gel/barrier interface below about 9.5 (pHIs below this value tend to deleteriously affect the integrity of the gel phase).
Gel pH can be determined at anytime/temperature. Determinatior of deleterious ~el defect~ as a result of acidic material in the barrier can bes-t be determined after the product: has been stored -for one week at 120F.

77~

The barrier phase embodiments of the prcsen~ Ven-tion provide the further advanta~e of havin~ shear rates rou~hly comparable to bo~h the ~el and the antiperspirant phases herein. Thus, the barrier phase when applied to the skin wears away at approximately the same rate as the gel phase and the antiperspirant phase. Undesirable phase protrusion that would occur were one phase worn away more slo~ly is thereby avoided. Ad~itionally, the barrier phases of the present invention provide the additional cosmetic ad-vanta~e of bein~ visually unnoticeable. The skilled artisancan easily formulate barrier phases and antiperspirant phases which have no readily ap~arent bounAary.

;

..
- 25a -~ .

.

7~
The two essential components of barricr ph.l5~5 hereill are alcohol-insolul)lc waxes and litluid organic emc)111ent~;. -~lcohol - Insol-lble Waxes ~n essential component of the barr1cr phase of the present antiperspirant stick compositions is a hic~h meltin~
point, water-insoluble wax or mixtures thereof which is in-soluhle in the polyhydrlc alcohol or mixtures thereof which are present in the gel phase ~i.e. alcohol solubility of less than 1~ at 80F.). Such waxes are a subgroup of those waxes suitable as the principal component of the preferred anti-perspirant phase of the stick compositions herein. Generally such waxes are non-polar compounds such as hydrocarbon waxes.
Suitable waxe~ have a melting point within the range o~ from about 150F. to 215F., preferably within the range of from about 170F. to 210F. Examples of suitable waxes are ~
ozokerite, paraffin, and ceresin. ~ -The barrier phase herein contains from about 10% to 40%, preferably from about 20% to 4~%, by weight of the bar- ~-rier phase of the alcohol-insoluble wax. The skilled ~ artisan will recognize that barrier phases containing higher ~ levels of the alcohol-insoluble wax will have less desirable .

cosmetic chatacteristics. The skilled artisan may then wish to adjust the maximum thickness of barrier phases having higher wax concentrations so as to alleviate the perception of toughness.

LIQUID ORGANIC EMOLLIENT
; A second essential component of the barrier phase is a llquid organic emollient. This lic~uid emollient component se~;~
to im?rove the cosmetic acceptability o~ the barrier phase herein in the same manner as the emollient compcnent o~ the :: :
~30~ antiperspirant phaseO The emollients suitable for use in the baxrier phase herein are the same as are used in the antiperspirarlt phase as described above. The emollient mponeDt compriseS ~rom about 20~ to 90'~, by WeiC~ilt 0~ the barrier pha~e.

, 7:~

Optional l3arrler }'ha<.e Compc)nen~s The barrier phase of the instant stic~ compositions can contain a variety of optional ingredients suitable for improving composi.tion stability, cosmetics or aesthetics so long as the barrier phase is relatively free of discreet particulate material and does not con-tain undesirable acidic materials. Such optional barrier phase components include low melting point waxes to adjus-t stick cosmetics, perfumes, dyes, preservatives and the like.
As noted, a highly preferred optional component of the barrier phase is an additional low-melting wax material or mixtures thereof having a melting point of from about 100F.
up to 150F. Such optional waxes are referred to herein as low melting point waxes. The low mel.ting point wax component can be used as an adjunct to the high melting point wax to provide improved emolliency and to enhance the structural inte- -grity of the barrier phase. The low melting point wax can also be used to adjust the feel of the stick compositions herein.
One sk~illed in the art will easily be able to make a product whi~h feels more brittle, soft, slippery, ~ticky, rough, etc.
by blending various suitable low melting point waxes with the essentially present high melting point waxes.
Examples of useful low melting point waxes include fatty acids containing from about 12 to 20 carbon atoms, ~ fatty alcohols containing from about 12 to about 20 carbon : ~ atoms, silicone waxes and glycerol monostearate. Especially : pre~erred materials of this type are the Cl2 to C20 fatty acids and Cl~2 to C20 fatty alcohols. The most prefexred low melting point waxes are ce~yl alcohol, stearyl alcohol, :30 myristyl~alcohol, lauryl alcohol and glycerol monostear~te~

: , 77~

If present, the lo~ meltincJ point WclX componcnt generally comprises from about 53 to 50~, and prc~erably from about 10% to 20~ by weig}lt of the barricr phase.
The barrier phase herein can also contain conventional S additives SUClI as dyes, perfumes, preservatives, deodorants, etc. I~ present, such materials should constitute a minor portion of the barrier phase, i.e., ~rom about ~ to 1.5%
by ~eight of the barrier phase.

~: :

: :
.

.
:' , :
.. .:
, , :
, , - f :~
- ,?B

7:~

CO`lPOSITIO~ PREI~R~IO~
. . _ The alltiE~erspirant, gcl and barricr p~lases of the present stick compositions are prepared separately. Tlle pre-~err~d waxy antiperspirant phase of the present colllpositions is generally prepared by heating the solid ~a~ and liquid emolllent in a suitahle container while gently stirring.
~hen the wax or waxes are melted and mixed thoroughly ~ith the emollient, the antiperspirant-active ingredient is mixed and dispersed in the melt. The optional ingredien-ts 0 can then be added or the melt can be cooled to a ternper-ature above the solidification point before adding addi-tional ingredients. The barrier phase of the present composition is generally prepared in tne same manner as the antiperspirant phase except that no particulate anti-~5 perspirant-active ingredient is added. Care should be ta~en in preparlng the preferred antiperspirant phases herein and the barrier phase to avoid use of any materials or proce-dures which might introduce free moisture into the composition above the substantially anhydrous level.
~o ~ The gel phase of the present compositon can be pre-pared~by ac~mixing the essential and optional gel phase com-ponents together in such a manner as to produce a thickened, stable gel. In a preferred rnode of gel preparation, the polyhydric allphatic alcohol and the monohydric alcohol are ~5 mixed together in a reflux vessel with rnoderate agitation.
Upon heatincJ the mixture to boiling, the gel-forming agents can be added under continuing refluxing and agitation until the gel-forming agent fully dissolves. Optional ingredients such as dyes, deodorants and perfumes can then be aclded.

`:

~:

Re~luxinc3 ancl moderate ac~itation is continued until boil-ing reoccurs if there has becn an apprccial)le ~cmperaturc drop due to the addi~ion of the optional m.lterials. Thc molten mixture can then be placeA in a mold device such S that the mi~ture is allowed to gel into a dimensionally stable mass o~ the desired geometric conficlura-tion.
Once prepared, the ~axy antiperspirant, gel and barrier phases of the compositions herein can be joined or eombined by any suitable means or in any suitable device so that a single antiperspirant stick is formed. In the stick product, the waxy antiperspirant and gel phases should be separated and isolated from each other by the interjacent barrier ph~se. The orientation of the phases should be such that all three phases are exposed in a single applieation sur~ace.
Re~erring now to the drawing, particularly to Figures 1 and 2 thereof, there is shown a preferred geometrieal embodi-ment of the present invention. The waxy antiperspirant phase is formed as a core 12 of any suitable shape, the barrier phase is formed as a sleeve 16 surroundinc3 the waxy antiperspirant phase or eore 12 and the gel phase is formed as a shell 14 ~-surrounding the barrier phase or sleeve 16. Most prefer-ably, the antiperspirant core 12, the barrier phase sleeve ~ -16, and the ~el phase shell 14 are in the form of eoneen-tric eylinders.
The three-phase eylindrieal stick composi~ions also possess a unique and appealing visual aesthetie quality.
Generally, the antiperspirant core phase and barrier phase are eaeh both opaque and white while the ~el phase shell is transluccnt or even transparent The ju~taposition of a whi~e, opaque eore and an encirelincJ translueent gel phase -~
particularly when colored, e.y~, blue -- brincJs to mind a "bull's-eye'~ and, henee, these three~phasc cylindrical sticks can be characterized as "~ull's-~ye" anti~erspirant sticks.
~ 30 -.

7:~

To prcparc three-phase cylinclrical "L)ull's-cyc" allti-perspirant s~ick compositions of this t~pe, the rnoltcn antiperspirant pllase mixture is poured in-to a cylindrical mold and allowed to set. Aftcr reaching room -tempcrature (75F.) the antiperspiran-t phase core is removed from the mold.
Thereafter, the core is dipped momentarily in-to the molten barrier phase mixture. Upon withdrawal from molten barrier phase mixture, the barrier coated core is again allowed to reach room temperature. The piece is then centered into 0 another mold whose inner diameter is the desired stick dia-meter. The molten gel phase which can contain colorants -~
is then added to the annular space and allowed to cool.
Upon cooling, the three-phase "bull's-eye" sticks of the present invention are removed from the mold.
Refexring again to the drawing, particularly to ~igure 2, the prepared antiperspirant stick 10~ is carried b~ a moveable, inner piston 20 to define a stick/piston piece 19. The piston 20 is housed within the hollow cylinder 18.
The tolerance between the stick~piston piece 19 and the '0 interior wall 21 of the cylinder 18 is such that the stick/
piston piece 19 can be manually pressed upward by exerting force on the piston's anterior face 22 to expose the distal end portlon of antiperspirant stick 10 for use.
In other embodiments of the present invention, shown ~-~5~ and illustrated in Figures 3 and 4, multiple phases can be sed. ~or example, with reference to Figurc 3, mul-tiple planar phases can be utilized~ if desired. ~lence,.a gen-;~ erally rectangular stick can comprise antiperspirant phases I2', ~el phases 14' and barrier phases 16'~ ~dditionally, for example, with reference to Figure 4, multiple concen- -tric phascs can be utilized, if desired. Thus, a ~cnerally circular stick can comprise antiperspirant l~hases 12'', ~el phases 14~i and barrier phase 16''.

CO~POSITION usr.
The three-phase antiperspirant stic~s o~ the present invention are used to inhi.bit axillary perspiration in the sa~e manner as any conventional antiperspi:rant stick com-pOsitiOIl. The present stick compositions can be easily applied to the skin lea~ing little or no perceptible residue.
Such sticks further provide cosmetically desirable appli cation characteristics such as glidability and coolness not generally provided by single phase stick compositions.
The three phase antiperspirant stick compositions herein are generally marketed in combination with some type of conventional packaging or dispensing means Such means can include handles, wrappers, tubes, extruding devices ..
(Figure 2) ànd the like. .
L5 The three-phase antiperspirant sticks of the present invention are illustrated by the following examples~

~ ~.

' . ' ~ .
, ~

: ~ :

:

7:~

~X~M~L~ I
~ three~phase antiperspirAnt stic~ of the followin composition is prepared.

Component Wt.%
A. Antiperspirant Core 48%
In~redient % by Weight Ozokerlte wax 5,0%
Cetyl alcohol 9.5%
Isopropyl palmitate 37.5%
.0 Aluminum chlorhydroxide particles 43.5%
[Al2 (OH15Cl 2112O~
Perfume 0-5%
*Cab-O-Sil (grade M-5) 4.0%
100, 0%
B. Gel-Phase Shell 48% :
Ingredient ~ hy Weight Ethanol 69%
Sodi.um Stearate 7,5%
Propylene glycol 20.00%
0 FD&C Blue #l (coloring: 0.5%0~25%
aqueous solution) Perf~ume Ø80%
: ~ Water : 2.45%
. 100.00%

' .
~ ~ .

,' : / 3-~ _ a~ 7~

.YA~1rI. (continued) C. Barrier Phase Sleeve (Thickness n.o20 inches) ~%
In~redient ~6 b~ ~1e~.g}lt Oæokerite Wax 306 Stearyl Alcohol 16.9 **Fluid AP ~(Propylene oxide/ 53.1%
butyl alcohol condensate) 100.0% 100.0 * A pyrogenic silica (Cabot Corp.) having a particulate diameter between about 0.01 and 0.03 microns as disclosed in British Patent 987,301 and British Paten-t 1,167,173.
** Butyl alcohol condensate with about 14 moles of propylene oxide marketed by Union Carbide Corp.
, .- ' .
:
' , . ''~.:

- 3~ -:: :
.

7 ~

In E~amp~e I, the stick is prepclred ~y fir,t forming the antiperspi~ t core by char~Jin~J a steel vc~ssel witl~ ~he ozokerite ~a:c, cctyl alcohol, ancl isopropyl myrisL.Ite ancl heating to approximately 200F. with the moderate agitation until these components are well intermi~ecl. ~e~t, the cab-o-sil is stirred into the mixture and is dispersccl therein. There-after, the aluminum chlorhydroxide powder ls likewise stirred into the mixture and is dispersed therein. This mixture is th~n allowed to cool to just above the solidification temperature 0 at which point the perfume is stirred into the mixture. The molten mixture is finally poured into the cylindrical mold;
is allowed to solidify by cooling to room temperature; and thereafter is removed from the mold to form the antiperspirant cores of the present invention.
The barrier phase components of ozokerite wax, stearyl alcohol and Fluid AP ~ of the specified proportions are charged to a second steel vessel and are heated with moderate agitation until well intermixed. The antiperspirant cores prepared as described above are dipped for about one second into the molten barrier phase mixture and then are ~ithdrawn. The antiper-spirant core/barrier sleeve pieces are then allowed to cool to room temperature.
The gel phase components are charged into a third steel vessel equipped ~ith a reflux condenser with the ethanol and the propylene glycol, and then are heated with moderate , agitat~ion until the mixture begins to boil and reflux. There a~ter, sodium stearate is added. The he~tincJ and agitation is ontinued until the soclium steara~e is completely dissolved.
N xt, the optional components comprising ~ater, the ~D&C Blue #1, : : ;
~;10 and~c perf~ are added while m~n~ining ~le agita~onc~nd refluYing. ~le - 35 _ `77~

molten gel material is then pourecl into the anrlular space of a suitable cylindrical mold into `hiC~I had beel~ centered the previously prepared antiperspirant core/~arrier phase piece. The molten gel~ is allowed to solidify to form the S shell of the three-phase stick of the present invention.
The stick so produced is an effective antiperspirant composition in the form of a three-phase stick. The stick exhibits rninimal syneresis and interfacial interaction and provides cosmetically desirable application characteris-O tics when applied to the skin.
Sticks of substantially similar physical/cosmetic character and antiperspirant effectiveness are realized when in the Example I stick the isopropyl palmitate of the anti-pexspirant core is replaced with an equivalent amount of isopropyl myristate, cetyl acetate, cetyl propionate, di-n butyl phthalate, diethyl sebacate, diisopropyl adipate, ethyl carbomethyl phthalate, Fluid AP ~ (Butyl alcohol con-densed with about 14 moles of propylene oxide) or DCC-225 Fluid ~dimethyl siloxane polymer of viscosity 9.5 cs. at o 25C. marketed by Dow Corning Cor~
Compositions of substantially similar physical/cos-metic character and antiperspirant effectiveness are realized when in the Example I stick the sodium stearate of the ~el ~ ~ phase shell is replaced with an equivalent amount of sodium palmitate, sodium myristate, potassium palmitate or potas-siwn stcarate.

' ,' ,:

~ ~ 3~ ~
- . : . .

E~X~ PI.l~

~ thrce-ph~se antiperspirant stick of t~le followin(;
composition is prepared:
~ nent Wt.
5 ~. ~ntiperspirant Core ~2o Ingredient % by ~eight Ceresin 80 506 Stearyl alcohol 10.0 ~luid AP ~ (Propylene o~ide/ 3S.9 0 butyl alcohol condensate) *Z~G (antiperspirant active powder~ 45.6%
100. 0%
B. Gel-Phase Shell 56 L5 Ingredlent ~ by Weight Sodi~ stearate 7.0 Propylene glycol 91.94%
FD&C Blue #1 (coloring) 0.26~ .
Perfume 0.806 - ~ :
i~O 100 . 0 C. Barrier_Phase Sleeve (Thickness 0.010 inch) 7 Ingredient % by Wei~ht Paraffin 10%
~tyristyl alcohol 30 5;~ Isopropyl myristate 60 100% 100 *ZAG is a complex formed from ZrO(OII)Clo3l~2O;
Al~(O~l)5C1~2~i2O and glycine in accordance ~.ith Luedders et al, U.S. Patent 3,792,0~8, issued Fe~ruary 12, 1974.
~10. : Particle Size Range = 1 - 44 microns.

~ . ,,~' ' "~ ~ :~7 - ~
- . , :
.

7:~

Such a stie~ is prepared in a manner simil.-r ~o that deseribed in Example Io The stic~ so pro~ue~d is an ef-feetive antiperspirant composition in the form of a three~
phase stick. The eomposition exhibits minimal interfacial s interclction and glides easily onto the skin during application.
Stick compositions of substantially similar physical/
eosmetic eharacter ancl antlperspirant effeetiveness are realized when in the Example II stiek composition the eeresin wax of the antiperspirant eore is replaced with an 0 equivalent amount of ozokerite, white beeswax o~ carnuba wax.
Compositions of substantially similar physical/
eosmetie eharaeter and antiperspirant effeetiveness are realized when in the Example II eomposition the propylene glyeol of the gel phase is replaeed with an equal amount of glyeerine, ethylene glyeol, or trimethylene glyeol.
Compositions of substantially similar stability are realized when in the barr1er phase of the Example II eompo-sition the paraffin is replaeed with an equal amount of eeresin or ozokerite.

, ':

:' ; ~ `:`' :: :
: ~ ' ~ ' :

~ 3~
:

.7~

~X~MPLE III
~ threc-phase antiperspirant stic~ composi~ion of the following composition is prepared:
Component _ Wt.
~. ntiperspirant Core 56 -In~redient % by Weic~ht _.
Carnauba wax lO.O~
Beeswax 5.0~
Stearyl alcohol 7.0%
~LU Isopropyl myristate ~ 24.0 DC-556* lO.0%
Aluminum chlorhydroxide 40,0 Aluminum chloride mixture*~
(~CII/AC wt. ratio = 3:l) Perfume l~0 . Bentone 38 ~ 3.0~
100. 0%
B. Gel-Phase Shell 42%
, Ingredlent ~ by Weight Potassium Stearate lO.0~
Ethanol 60.55%
Propylene glycol 29.0~
FD&C Blue $1 (coloring, 0.5% 0.15~ ;
: aqueous solution) Triclosan *** ~ 1. 0% . ::
:(deo~orantj Klucel ~ (antisyneresis a~ent) 0.5%
: : :: :
~; Pexfume 0.8 100.0%
~30 ~ *DC-556 in tris (trimethylsiloxy) phenylsilal-le mar~eted by Dow~Corning Corporation.
~ : :
~ **~luminum chlorhydroxide is Al2(OII)5Cl^2~12O

.
Aluminum Chloride is ~lCl3~6il2O . :
*** 2 llydroxy 2'-4, 4'-Trichlorodiphenyl. oxi.de ~ )[~lic~(3 by Ciba-Gei~y Corp. ~ ~-3'~ ~
- , . , - . . -7:~

C. Barrier Phase Sleeve ~Thic};nec.s: 0. 010 inch) 2 Inqrcclient~ hy ~7ei(Jht Ceresin 30'6 Isopropyl palmitate 70%
100% 100%

, .
:
: ' :; ~ ':' ' .
.
.

: : : :

: :

~: :

:
.

, : ,' -~- ~l O
.

77~

Such a stick is prepared i.n a ma~ cr ;.i.mi:Lar ~o that describccl i.n E~am~le I. Tile stick~ so produ~ed is an effective antiperspirant/deQdorant composition in the form of a three-phase stick. The composition exhibits minimal interfacial interaction and provides a cooling sen-sation when applied to the skin.
Stick compositions of substantially similar physical/
cosmetic character and antiperspirant/deodorant efective-ness are realized when, in the Example III composition, the stearyl alcohol of the antiperspirant core is replaced ~ith an equivalent amount of cetyl alcohol, myristyl alcohol, lauryl alcohol or glycerol monostearate.
Stick compositions of substantially similar physical/
cosmetic character and antiperspirant/deodorant effective~
ness are realized when, in the Example III composition, the aluminum chlorhydroxide/aluminum chloride mixture is replaced with an equivalent amount o a particulate anti-perspirant active material selected from the group consisting o Z~G complexes wherein the zirconium compound is ZrO(O~I)2 aCla nH2O with a = 1.5 to 1.87 and n a 1 to 7;
the aluminum compound is A12(OH)5Cl 2H2O and -the amino acid compound is glycine: That is,the above represents any aluminumjzirconium/chlorhydroyide salt having an Al:Zr molar ratio range of about 1.67 to 12.5 and a Metal:Cl r~lolar ratio range of about 0.73 to 1.93.
Stick compositions of su~stantially similar physical/
cosmetlc character and antiperspirant/deodorant effective-:~ ness a~e realized when in the E~ample III stick composi-tions the ethanol of the ~el phase is replaced by an equivalent amount o~ methanol, isopropanolr or n-propanol.
:
;: :

:
: ~ ~ , , . - . :
- - . . . . . . . .

r~ N l.V~LU~TIO~l ~s notcd above, a barrier phase of specifiecl compo-si-tion ~hich is free of particulate materia:l. ancl has a speci-ficd minimum thickness is essential to the realization of antiperspirant sticks which are not subject to decJrada-tion by inter~acial interaction. The impor~ance of such essential elements of the barrier phase can he demonstra-ted by formulating stic~ compositions with barrier phases containing various types of waxes and by formulatlng stick compositions with barrier phases containing various particu-late materials such as talc, particulate active, and kaolin, and then observing such compositions after a one ~1eek stGrage at 120F. Those compositions subject to interfacial inter-action can be identified by the presence of a liquid runoff present in the bottom of the container holding the three-phase sticks and/or plasticization of -the antiperspirant cc>re phase. Further visual evidence of interfacial inter-action is the shrinking of both the gel and the anti.perspirant phases. ~.
Storage at 120~F. is a relatively harsh test condition.
Even barrier-free sticks which would remain stable under milder test conditions ~e.g., room temperature) for as long as two months mic~ht show appreciable interfacial interaction :~ after only the one week at the elevated 120F. storage tem-~5 perature~ Thus, sticks which do not exhihi-t interfacial interaction a~ter one week at the elevated temperature storage : are very stable sticks. Of courseS, it is realized that pro~
longcd storage at elevated tempera~ures or s~orage at even ; higher temperatures will induce degradatiol- in even the barrier- containing sticks of the present invention.
Several stick composltions ar~ se~ccted roi- such : intcr~acial interaction evaluatio!l at 120~1. for one week.
The compositions ~ested a1-e thosc descrihcd in Tablc I.
~ - ~2 -~ 1 a~ l ~ O ~-- O '~ Ir) O O O 0 0 O O O
~ ~o ~ o ~ o ~ o 't~l ~ t-1 ~
~) u ~n o ~I o ~o ~ o o o c~ In o o o ~r 1~l o ~r ~r ,_~ o ~ ~ J O
,_1 t-~
'~ 1 1` ~ ~ lo ~ o 0~ o lo o o Cl ca O o c~ lo X H t~ ~ ~ ~ 1 ~ ~ 1 t~ t~
I ~ ~ O ~ lo ~ o ~ o o lo o c~ I~ (~ In o o lo O C) ~ ~ o ~ 1~ t~ o ~ ~ ~ ~ o æ ~ ,~ ,~ ,~ .
O ~ ~~ o t~ ~ lo ~ ~ ~D o olo ~ o t~ o ~ lo ~ C~ 1,~ 1 1 H (;5 P~ ~1 ~r~ o 1~ o c~no o 00 ocoOO o

4~ ~ ~I ~t~ t~ "~
(3 t-l t~
.
.~ . ~. . , ~1 a~ r~ ~ ~ I` ~ n c o 0 ~ o co o o o ~: ~D ~ O ~r ~ ~ o . .~ ~ ~r ~ o t-~ ~ t-t t~ ~
P~
~I c~ ,~o o o p~ O o: u~ o o o o ~`~ ~ o ~ o ') ~D O ~ ') t~ O f/) t~ O :~-4~ C) ~"~ ,,, ~I co ~ r~ ,~ O l_ O c~ u) olo u~ o r~ o o~ O olo .~ . ~ " lo ~ ~ ~ ~ t-l 1 ~ .
h .1C ) ¦ I--~1 O -1 O r~ o ~ O O o o I--ul co o O :.
Q) ~ r r-l CO ~1 r~ o ~ H ¦ ~
,~ mI ~ O co U~ O O
~ ~ O ~,~
H ~ ~r7 0 ~) ~ O G~ 0 O o o Ct~-l O ~ll(lt-J O
t~ :
E~ ~
~ ~ Q) . .
~ S~ ~J
O t~ 't-J O O Ei ~ O
rl s ~ ~ o ~ O ~ , ~) ~3 r~l C-) ! '~ (~) (I) O U~ ~ r~
.,.~ r-t 11) ~ rt rt R~ rl X rt Q~ ~i r~ E~ O r~ ~ O ~ ~: h ~ ~ O
tl) ~ C~ ~ O O S-l S-l rt O a~ ~ 5-1 h ~a S~ rt 11~ Ol-rt X (~ -1 X ~ -r-l O
t~ ~ a .c o l ~ o a~ O ~ ~ o c) cl O : ~ r l t~
_ O ~ N ~ U~ r l C~ N (I) ~) u H U~ L P~ O O u~ H fl O O ~ H h~ E-~
, ~ X F~
U u~ X
~ I¢ rt r~ ~rt u~
~
Z ~ O

H ~J ~C
~; ~ rq ~LI rq ~--I 3 d~ H r~. ~ ~ o~
~r , .

.
.~ '.

7~

call be seen from the a~ove 'l`abLe I, conlposi~ions through E exhibit interfacial interac~ioll while compo-sitions F through J do not exhibit such degraclation.
Compositions F - J represent compositions of the present S invention inasmuch as these compositions contain a barrier phase of the requisite composition, minimum thickrless and which is relatively free of partlculate materials. Compositions A-E either do not contain a barrier phase or have a barrier phase either containing a high melting point wax which LO is soluble in the gelling solution or containing significant amounts of particulate materials. These compositions without barriers or with defective barriers are thus subject to inter-facial interaction.

.

'~ :

.

.
:

:
"
... . . . . . . . . . . .

Claims (12)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. An antiperspirant composition in the form of a three-phase stick, said composition comprising:
A) from about 35% to 65% by weight of the composition of an antiperspirant phase comprising a solid, shear-able vehicle which contains an astringent antiperspirant material;
B) from about 35% to 65% by weight of the composition of a gel phase, said gel phase comprising I. from about 10% to 92% by weight of the gel phase of a polyhydric aliphatic alcohol con-taining 2 to 3 carbon atoms and from 2 to 3 hydroxy groups:
II. from about 5% to 15% by weight of the gel phase of a gel forming agent selected from the group consisting of sodium and potassium salts of fatty acids containing from about 14 to about 18 carbon atoms; and C) from about 1% to 10% by weight of the composition of an interjacent barrier phase contiguous to the gel phase and the antiperspirant phase, wherein the barrier phase has a thickness of at least about 0.005 inch and comprises;
I. from about 10% to 40% by weight of the barrier phase of a water-insoluble, alcohol-insoluble high melting point wax or mixtures thereof which has a melting point of from about 150°F. to 215°F.; and II. from about 20% to 90% by weight of the barrier phase of a water insoluble, liquid organic emollient, and wherein the barrier phase is relatively free of parti-culate materials and is free of materials capable of reducing the pH of the gel phase below about 9.5 in the region of the gel/barrier interface.

2. A composition in accordance with Claim 1 wherein A) the antiperspirant phase comprises I. from about 2% to 15% by weight of the antiperspirant phase of a water-insoluble high melting wax or mix-tures thereof which has a melting point of from about 150°F. to 215°F.
II. from about 20% to 50% by weight of the antiperspirant phase of a water-insoluble liquid, organic, emollient;
and III. from about 11% to 50% by weight on an anhydrous basis, of the antiperspirant phase of a solid parti-culate astringent antiperspirant material; and, B) wherein the gel phase additionally contains from about 10% to 72% by weight of gel phase of a mono-hydric alcohol selected from the group consisting of methanol, ethanol, isopropanol, and n-propanol, and wherein the weight ratio of polyhydric alcohol to gel-forming agent in the gel phase exceeds about 2.45; and

3. A composition in accordance with Claim 2 wherein the antiperspirant phase comprises a core, the barrier phase comprises a sleeve surrounding the antiperspirant phase barrier and the gel phase comprises a shell sur-rounding said phase.

4. A composition in accordance with Claim 2 wherein the barrier phase ranges in thickness of from about 0.010 inch to 0.040 inch and contains no more than about 0.01% of particulate materials having a particle size of greater than about one micron.

5. A composition in accordance with Claim 4 wherein A) the high melting wax comprises from about 3% to 11% by weight of the antiperspirant phase and is selected from the group consisting of beeswax, carnauba, bayberry, candelilla, montan, ozokerite, ceresin, paraffin, Fisher-Tropsch waxes and micro-crystalline waxes and mixtures thereof;
B) the organic emollient comprises from about 30% to 40% by weight of the antiperspirant phase and is selected from the group consisting of isopropyl myristate, isopropyl palmitate, cetyl acetate, cetyl propionate, di-n-butyl phthalate, diethyl sebacate, diisopropyl adipate, ethyl carbomethyl phthalate, the condensation product of about 14 moles of propylene oxide with one mole of butyl alcohol, and polydimethylsiloxanes having a vis-cosity of from about 9 to 50 cs. at 25°C.;
C) the particulate antiperspirant material comprises from about 30% to 46% by weight on an anhydrous metal salt basis (exclusive of complexing agents) of the anti-perspirant phase and is selected from the group con-sisting of i) aluminum hydroxyhalides of the empirical formula Al2(OH)xQy?XH2O wherein Q is selected from the group consisting of chlorine, bromine and iodine, wherein X is from 2 to 5 and x + y = 6 and wherein X is 1 to 6; and ii) zirconium/aluminum/amino acid complexes which contain a) one part of an aluminum compound of the for-mula Al2(OH)6-mQm?YH2O wherein Q is selected from the group consisting of chloride, bro-mide and iodide; m is a number from about 0.8 to 2.0 and Y is 1 to 6;
b) x parts of a zirconium compound of the for-mula ZrO(OH)2-aQa?nH2O wherein Q is selected from the group consisting of chloride, bromide and iodide; wherein a is from 1 to 2, wherein n is from 1 to 8 and wherein x is from about 0.16 to about 1.2; and c) p parts neutral amino acid selected from the group consisting of glycine, d1-tryptophane, d1-.beta.-phenylalanine, d1-valine, d1-methionine and .beta.-alanine, and wherein p has a value of from about 0.06 to about 0.53;
D) the polyhydric aliphatic alcohol comprises from about 15% to 50% by weight of the gel phase and is selected from the group consisting of ethylene glycol, pro-pylene glycol, trimethylene glycol, and glycerine;
E) the monohydric alcohol comprises from about 40% to 70%: by weight of the gel phase and is selected from the group consisting of ethanol and isopropanol;
F) the water insoluble, alcohol-insoluble high melting point wax of the barrier phase comprises from about 20% to 40% by weight of the barrier phase and is selected from the group consisting of paraffin, ozokerite and ceresin; and G) the barrier phase further comprises from about 10%
to 30% by weight of the barrier phase of a low melting point wax or mixtures thereof having a melting point of from about 100°F. to 150°F.

6. A composition in accordance with Claim 5 wherein the gel-forming agent comprises from about 7% to 10% by weight of the gel phase and is selected from the group consisting of sodium stearate, sodium palmitate, sodium myristate, potassium stearate and potassium palmitate.

7. A composition in accordance with Claim 5 wherein the low melting point wax is selected from the group con-sisting of cetyl alcohol, stearyl alcohol, myristyl alcohol, lauryl alcohol and glycerol monostearate.

8. A composition in accordance with Claim 5 wherein the antiperspirant core contains an additional component selected from the group consisting of A) from about 2% to 20% by weight of antiperspirant core of a low melting point wax or mixtures thereof having a melting point of from about 100°F. up to 150°F.;
B) from about 0. 5% to 5% by weight of antiperspirant core of an inert filler material; and C) combinations of both said low melting point wax and said inert filler.

9. A composition in accordance with Claim 5 wherein the gel phase shall contains an additional component se-lected from the group consisting of A) from about 0.1% to 1.0% by weight of gel phase shell of a deodorant material;
B) from about 0.1% to 5.0% by weight of gel phase shell of an antisyneresis/evaporation retardant selected from the group consisting of carboxy-alkylcelluloses and hydroxyalkylcelluloses; and C) combinations of both said deodorant material and said antisyneresis/evaporation retardant.

10. A composition in accordance with Claim 5 wherein A) the high melting point wax is selected from the group consisting of ceresin, beeswax, ozokerite and synthetic waxes;
B) the emollient is selected from the group consisting of isopropyl myristate, isopropyl palmitate, the condensation product of about 14 moles of propylene oxide with butyl alcohol and polydimethylsiloxanes having a viscosity of from about 9 to 50 cs. at 25°C.;
C) the antiperspirant material is in impalpable particu-late form and is selected from the group consisting of i) Al2(OH)5Cl?2H2O
ii) mixtures of AlCl3?6H2O and Al2(OH)5Cl?2H2O in an aluminum chloride to aluminum hydroxychloride weight ratio of up to 0.5;
iii) zirconium/aluminum/glycine complexes containing about one part Al2(OH)5Cl?2H2O; x parts of ZrO(OH)Cl?3H2O and p parts glycine wherein x is from about 0.16 to 1.2 and p is from about 0.06 to 0.53; and iv) zirconium/aluminum/glycine complexes containing about one part Al2(OH)5Cl?2H2O; x parts of ZrO(OH)2-aCla?nH2O; and p parts glycine wherein a is from about 1.5 to 1.87, n is 1 to 7, x is from about 0.16 to 1.2 and p is from about 0.06 to 0.53;

D) the polyhydric alcohol is propylene glycol; and E) the gel forming agent comprises from about 7% to 10% by weight of the gel phase and is selected from the group consisting of sodium stearate, sodium palmitate, sodium myristate, potassium stearate and potassium palmitate.

11. A composition in accordance with Claim 10 which contains an additional component selected from the group consisting of A) from about 5% to 15% by weight of the antiperspirant core of low melting point wax present in the anti-perspirant core, said low melting point wax being selected from the group consisting of cetyl alcohol, stearyl alcohol, myristyl alcohol, lauryl alcohol and glycerol monostearate;
B) from about 0.5% to 5% by weight of the antiperspirant core of an inert filler present in said antiperspirant core, said filler being selected from the group consisting of talc, colloidal silicas and hydro-phobic clays;
C) from about 0.1% to 5.0% by weight of the gel phase shell of an anti-syneresis agent present in said gel phase shell, said anti-syneresis agent compris-ing hydroxypropylcellulose compounds having mole-cular weights ranging from about 60,000 to 1,000,000;
D) from about 0.1% to 1.0% by weight of the gel phase shell of a deodorant material present in said gel phase shell, said deodorant material being selected from the group consisting of bacteriostatic quater-nary ammonium compounds, metal salts of monohydroxy-benzene sulfonic acids, halogenated dihydroxydiphenyl methanes and derivatives of 1,3-dipheny-urea having one or more hydrogen atoms replaced with halogen;
and E) Various combinations of said additional components.

12. A composition in accordance with Claim 3 wherein the core and sleeve phase are of dissimilar color.