CA1076030A - Water-in-oil emulsion with non-ionic surfactant in antiperspirant - Google Patents

Abstract

WATER-IN-OIL EMULSION WITH NON-IONIC
SURFACTANT IN ANTIPERSPIRANT

ABSTRACT OF THE DISCLOSURE
Aerosol antiperspirant compositions comprise an aqueous solution of at least one astringent salt emulsified as a water-in-oil emulsion in an organic phase comprising at least one emollient oil, at least one water-in-oil emulsifying non-ionic surfactant and a liquified propellant.

Description

1076~30 The present invention is directed to novel aerosol antiperspirant compositions.
Currently-marketed aerosol antiperspirant com-positions are anhydrous suspensions of aluminum salts of strong acids in organic liquids which include a propellant.
The salts in the suspension must be of very small particle size to minimize the tendency for the solids to separate from the liquid phase and to achieve satisfactory dispen-sing from the container.
Aqueous aerosol perspirant compositions have not been used because of problems which are encountered when contained in conventional aerosol containers. The major problem is corrosion caused by the corrosive action of the aluminum salt in solution and an additional problem is valve ~ clogging resulting from salt crystallization.
;~ In accordance with the present invention, there is provided an antiperspirant composition comprising an aqueous solution of an astringent salt formulated as a stable water-in-oil emulsion in a continuous organic phase comprising an emollient oil and a liquified propellant.
~` Since the aqueous phase is in a stable emulsified ~ form, the electrochemical reactions necessary for corrosion - are prevented and hence the prior drawbacks to the use o~- aqueous solutions of astringent salts in aerosol anti-perspirant compositions are overcome.
The aqueous emulsion system utilized in the present invention provides an effective antiperspirant preparation in aerosol form that is a wet spray when applied to the skin, imparts a feeling of lubrication and minimizes valve clogging.
The active ingredient used in the compositions -~ of this invention is one or more astringent~salt, usually 1076~)30 astringent salts of zinc, magnesium, zirconium and aluminum, preferabiy aluminum.
Examples of suitable aluminum salts are aluminum chloride, aluminum sulphate, aluminum phenolsulphonate, aluminum chlorhydroxide, aluminum chlorhydroxide polyol ` derivatives and basic aluminum bromide. The equivalent zinc, magnesium or zirconium salts may be used.
The preferred astringent salts are aluminum chlor-hydroxide, aluminum chlorhydroxide polyol derivatives and aluminum chloride.
The astringent salt component is present in a quantity of about 1 to about 25% by weight of the composition, prefer-ably about 2 to about 20% by weight.
. .
- The deodorant properties of the composition may be enhanced by the optional presence of one or more topical antimicrobial agents to inhibit the growth of bacterial flora that may decompose body perspiration.
When such microbial agents are present, they are included generally in a quantity of up to about 1% by weight of the total composition, preferably about 0.01 to about 0.2~ by weight.
Typical examples of suitable antimicrobial agents are the materials kno~m by the trademarks DOWICIL 200, VANCIDE 89RE, IRGASAN DP-300 and BRONOPOL. The material Dowicil-200 is N-(3-chloroallyl)-hexammonium chloride, the material Vancide 89RE is N-trichloromethylthio-4-cyclohexene-1,2-dicarboximide, the material Irgasan DP-300 is 5-chloro-2-(2,4-dichlorophenoxy)-phenol and the material Bronopol is

2-bromo-2-nitropropane-1,3-diol.
The astringent salt(s), along with any antimicrobial agents if present, are dissolved in water, preferably ~ 3 ~
I

10~6~30 deminera~ized water. The quantity of water used is in the range of about 5 to about 65% by weight of the composition, preferably about 25% by weight.
The organic phase of the composition comprises liquified propellant and at least one emollient oil. The ~ liquid propellant may be any convenient propellant or mixture of propellants, having the desired vapor pressure to effect dispensing of the contents of the container in which the composition is packaged. Generally, the vapor pressure of the finished product is in the range of 15 to 65 psig at 70F, and preferably 20 to 50 psig. The propellant may be one of the well known fluorocarbon propellants, such as, "FREON"
(Trademark) 11, Freon 12 and Freon 114.
Since some fluorocarbons have been associated with a theory concerning stratospheric ozone damage, it is preferred to use other chemically-stable, non-toxic materials, which are gaseous at room temperature and atmospheric pressure but liquid under the aerosol can pressure.
; The propellant should be one which does not react with any of the components of the emulsion while in the aerosol container and which does not adversely affect the performance of the composition when sprayed on the skin.
Preferred propellants are hydrocarbons, such as, n-butane, isobutane and propane and partially halogenated hydrocarbons, such as, l-chloro-l, l-difluoroethane.

The quantity of propellant ~sed depends on the proportions of the other ingredients and its vapor pressure at atmospheric pressure and should be sufficient to effectively dispense all the contents from the con-tainer. ~onorally, thc quantity of propellant used is .~ '`
about 8 to about 80% by weight of the composition.
The emollient oil imparts several important properties to the system. For example, its presence enables a stable emulsion to be formed, the oil lubricates the valve and the oil provides a smooth, soft feel to the skin.
The emollient oil should be liquid at room temperature and substantially insoluble in water. Any member or mixture of members of a large group of cosmetic - emollients which have been employed in topical prepara-tions, may be used.
The emollient oil is preferably a non-ionic - material. Examples of suitable materials include long chain fatty alcohols of C12 to C24 carbon chain length, such as, isostearyl alcohol; liquid lanolin; long chain carboxylic acids of C12 to C24 carbon atoms, such as, isostearic acid and C3 to C8 alkyl esters of such long chain carboxylic acids, such as, isopropyl and butyl esters of myristic, palmi~ic and isostearic acids;
triglycerides of short, medium and long chain carboxylic acids, such as, caprylic, capric and lauric acids; polyols of medium chain carboxylic acids of C9 to C12 carbon atoms, such as, propylene glycol dicaproate or dicaprate and propylene glycol dipelargonate; saturated hydrocarbon esters and alcohols of lanolin, such as, purified squalane;
phenyl methyl silicones; and dimethylsilicones, such as dimethicone and cyclomethicones.

The emollient oil or oils is present in quan-tities of about 3 to about 20~ by weight of the composition, preferably about 4 to about 10~ by weight.
The composition also contains at least one water-in-oil emulsifying non-ionic surfactant to form a stable water-in-oil emulsion from the aqueous and organic phases. The surfactant or mixture of sur-factants used should have a hydrophilic-lipophilic balance (HLB) of less than about 7. When a mixture of surfactants is used, one or more components of the mixture may have an HLB value greater than 7. This may even be desirable under certain circumstances, but it !~' iS essential for the mixture to have an overall LHB
value of less than about 7.
Examples of suitable non-ionic surfactants useful in the compositions of the invention are lanolin . :
alcohols; ethylene and propylene glycol esters of medium ~` and long chain fatty acids of C9 to C24 carbon atoms, such as lauric, oleic, ricinoleic and stearic acids;
glyceryl and polyglyceryl esters of such acids; sorbitol esters of such acids; and phosphate esters and alkanol-amides of various fatty acids. A preferred surfactant is polyglycerol 4-oleate.
The emulsifying surfactant gcnorally is present in the composition in an amount of from about 0.1 to about 5% by weight of the composition, preferably about 0.3 to about 2.5% by weight.
Supplementary emulsifiers, viscosity-increasing agents and emulsion stabilizing agents also may be in-cluded in the composition, such as, colloidal aluminum and magnesium silicate clays, for example, bentonites and hectorites, and colloidal silicas. Examples of 1076~30 suitable materials are those known by the trademarks Bentone 38, Bentone 34, Cab-O-Sil, Syloid and Aerosil.
The supplementary materials may be present to aid in the stability of the emulsion and decrease the possible inci-dence of valve clogging. Silicas may be present to increase the smooth feel of the product when applied to the skin.
Such supplementary materials may be present in quanti-ties of up to about 5% by weight of the composition, preferably about 0.01 to about 0.5% by weight of the composition.
The composition may also contain one or more fragrances, usually in quantities up to about 2% by weight of the composition.
The invention is illustrated by the following Examples:
Example 1 .
An antiperspirant composition was formulated and packaged in an aerosol can under pressure. The formulation - had the following composition:
Component % by Weight ; Aluminum hydroxychloride 7.00 Polyglycerol 4-oleate 0.40 Cyclomethicone 2.00 Isopropyl myristate 5.49 Bentone 38 0.01 Fragrance 0.30 Deionized water 27.80 Isobutane 57.00 The formulation was applied to the right axilla of a panel of females with the left axilla left as control. Tabu-lation of the results obtained demonstrated a 33.8 mean %
decrease in perspiration formation in the right axilla, a value considered commercially acceptable.

1076~0 Examples 2 to 4 A number of additional antiperspirant composi-tions were formulated in an aerosol can under pressure.
The compositions which were effective antiperspirants had the following ingredients:
Examplé 2 ~ by weight Aluminum chloride hexahydrate 2.0 Aluminum chlorhydroxide 5.0 Ta,c 3.0 Cabosil M-5 0.4 Alkanolamide (Emcol 511) 1.0 Isostearyl alcohol 11.4 ) Fragrance 0.2 Deionized water 20.0 Isobutane . 57.0 Example 3 - -Magnesium chloride hexahydrate 3.0 Aluminum Chlorhydroxide 3.5 Water 17.7 Water-insoluble starch 3.5 Vancide 89RE 0.05 Cedepal E-400 1.45 Bentone 34 0.6 Butyl Stearate 9.9 Fragrance 0.3 Normal Pentane 10.0 Isobutane 50.0 ~ by weight Example 4 Aluminum chlorhydroxide polyol derivative 15.0 Water 39.0 Polyglycerol 4-oleate 0.7 Isopropyl palmitate 10.0 Fragrance 0-3 Isobutane 29.75 Propane 5.25

Claims (4)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. An aerosol antiperspirant composition, consisting essentially of:
about 1 to about 25% by weight of at least one astringent metal salt, about 5 to about 65% by weight of water, about 8 to about 80% by weight of at least one liquified propellant which is gaseous at room temperature and atmospheric pressure, about 3 to about 20% by weight of at least one emollient oil liquid at room temperature and insoluble in water, about 0.1 to about 5% by weight of a non-ionic surfactant or mixture of non-ionic surfactants having an HLB value of less than about 7, 0 to about 1% by weight of at least one antimicrobial agent;
0 to about 5% by weight of at least one supplementary stability imparting agent; and 0 to about 2% by weight of at least one fragrance, said composition being formulated as a stable water-in-oil emulsion of a solution of said at least one astringent metal salt dissolved in the water dispersed in the mixture of at least one propellant and at least one emollient oil.

2. The composition of claim 1 wherein said astringent salt is present in a quantity of about 2 to about 20% by weight.

3. The composition of claim 1, wherein said emollient oil is present in an amount of about 4 to about 10% by weight.

4. The composition of claim 1, wherein said surfactant is present in an amount of about 0.3 to about 2.5% by weight.