JPH0347249B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to water-in-oil emulsions containing organic lactates, particularly water-in-oil creams containing ethyl lactate suitable for the treatment of acne. The main symptom of acne is abnormal keratinization above the sebaceous gland of the hair follicle. When the antral pores become blocked by aggregated keratinized cells, comedones form. When these keratinocytes gather, the vesicles can deteriorate into cysts, which can further deteriorate into inflammatory lesions such as papules or non-inflammatory lesions such as open comedones. In the case of microcysts, the external opening of the vesicle is not visible, but in the case of open comedones, the external opening becomes swollen with a mass of darkly pigmented keratinocytes. As acne progresses, the vesicular epithelium collapses into a rash and becomes a dermis of keratin and sebum. Sebum contains free fatty acids derived primarily from the lytic effects of bacterial lipases (particularly from Propionibacterium acnes) on sebum triglycerides. Inflammation due to released free fatty acids and other bacterial by-products may ensue, and a lymphocytic reaction may transform the microcyst into a papule or even into a pus-filled pustule. sell. Therefore, it suppresses the release of these bacterial byproducts, which are a type of free fatty acid, from sebum triglycerides,
A treatment method that prevents the keratinization of antral follicles is effective in reversing the main symptoms of acne and preventing new acne lesions.
In particular, it is clear that it limits the progression of non-inflammatory lesions (comedones). In the past, various attempts have been made to eliminate microorganisms such as P. acnes and limit the release of these bacterial byproducts, but the success rate of these attempts has been low. For example, the use of antibiotics is effective in this regard, but excessive use of such drugs is unacceptable due to their effect on the intestinal flora and the development of antibiotic-resistant strains of pathogenic microorganisms. I don't get it. Attempts to topically apply skin-tolerant organic acids, such as lactic acid, to acne comedones have also had limited success. This is because the acids are incapable of maintaining skin PH low enough to inhibit skin microbial growth long enough to regress the disease. British Patent No. 1388836 (Medisan) states:
It has been proposed to treat acne with lactic acid esters such as ethyl lactate in the form of an anhydrous alcoholic solution, and British Patent No. 1555796 (Unilever) describes the treatment of acne with a C ₁ -C ₄ alkyl lactate and a C ₂ It has been proposed to treat with aqueous compositions containing ~ _C4 alkylene glycols. The product described in the Unilever patent and sold under the trade name TRI-AC is available in the UK in the form of a clear liquid lotion.
Although it has been reported in medical journals that this product can be an effective topical treatment for acne conditions, this type of fluid lotion has a tendency to run away from acne lesions, so do not use this type of lotion on the affected areas of the face. It is difficult to apply accurately, and some consumers have disliked its use. Additionally, consumers may not be willing to accept that clear liquid lotions contain therapeutic active ingredients. Such sores generally require a liquid lotion that does not run off from the affected area, can be applied accurately and easily to the face, and that must be most effective in treating the sore condition. It is preferred to use opaque creams that leave a sign on the skin after application that the product has been applied topically. Therefore, there is a strong consumer desire for creams containing ethyl lactate for the topical treatment of acne.
It is the object of the present invention to provide such a cream. C ₁ -C ₄ alkyl lactates, including ethyl lactate, are volatile polar organic liquids, and it is extremely difficult to prepare creams containing them in common emulsions such as cosmetic creams. The problem is that it is usually unstable and syneresis occurs rapidly, making it unsuitable for mass production. The inventors have discovered that stable creams can be prepared by careful selection of the particular volatility of the oil phase of the emulsion. Such emulsions have similar appearance, feel and subjective properties to ordinary creams;
Furthermore, even if stored at high temperatures for several months, it remains stable without showing any syneresis. Therefore, it is particularly suitable for storing on retail store shelves until sale or at home until use without causing deterioration. Therefore, the water-in-oil emulsion suitable for topical use on human skin for the treatment of acne obtained according to the present invention contains, in addition to water, the following components: 2 to 30% by weight of alkyl lactate (C ₁ to C ₄ ) or a mixture thereof; silicone oil in which a polymer of dimethylpolysiloxane and side chain polyoxyethylene and/or polyoxypropylene is dispersed in volatile siloxane Component 15-50% by weight: This polymer has a molecular weight of 10,000-50,000 and a structure of the following formula. Here R is and a is 9-115 b is 0-50 x is 133-673 y is 25-0.25; Nonionic liquid emulsifier with HLB value 1-7 0.5
~10% by weight; 5-40% by weight of _C1 - _C4 alkanols or mixtures thereof. In the emulsion, the aqueous phase constitutes 10-98% by volume and the oil phase constitutes 2-90% by volume. The emulsion of the present invention is composed of an internal (discontinuous) phase that is aqueous and an external (continuous) phase that is oily. The aqueous phase is usually 10-98% of the emulsion.
% by volume, preferably 50-90% by volume, and the oil phase usually comprises 2-90% by volume of the emulsion, preferably
10-50% by volume. The emulsion of the present invention has alkyl lactate (C ₁ -
C ₄ ) or a mixture thereof. Examples of alkyl lactates include methyl lactate, ethyl lactate, n-propyl lactate, iso-propyl lactate, n-butyl lactate, iso-butyl lactate, and tert-butyl lactate. A preferred lactic acid ester is ethyl lactate. The reason why the above types of lactic acid esters are effective in treating acne is that the esters pass through the epithelium and connect the sebaceous glands and the intact hair follicles.
It is thought that this is because the esters reach the sebum of the follicle (intact), where they are dissolved in the sebum lipids, where hydrolysis by lipase derived from bacterial contaminants occurs, converting the esters into the corresponding acids and alcohols. It is thought that the alcohol produced in this way exhibits antibacterial activity when formed in situ within the sebaceous glands. That is, the number of bacteria can be reduced. If not,
Bacterial lipase activity will cause hydrolysis of sebum triglycerides, releasing free fatty acids and forming acne. Also, in
Lactic acid generated in situ can suppress the surrounding pH by bacterial lipase activity. It can be lowered to a value lower than PH6. Furthermore, it also appears that free lactic acid can reduce keratinization. The overall result is that the release of free fatty acids (which is involved in the exacerbation of acne) from sebum lipids is suppressed and the acne condition may be improved. Alkyl lactate (C ₁
The amount of ~ _C4 ) is from 2 to 30% by weight, preferably from 5 to 20% by weight, based on the total weight of the emulsion in which it is used. Emulsions containing less than 2% by weight of alkyl lactate appear to be ineffective in treating acne, and emulsions containing more than 30% by weight of alkyl lactate appear to be ineffective in treating this condition.
It does not appear to be more effective than emulsions containing up to 30%. Furthermore, 30% by weight of alkyl lactate
Application of emulsions of this type with higher concentrations to the skin may cause some irritation to the skin. The emulsion of the present invention also contains a silicone oil component. This component is a dispersion of a polymer consisting of dimethylpolysiloxane and polyoxyethylene and/or polyoxypropylene side chains in a volatile siloxane. This polymer has a molecular weight of
10,000 to 50,000 and has the structure of the following formula. Here, R is , a is from 9 to 115, b is from 0 to 50, x is from 133 to 673, and y is from 25 to 0.25. Preferred dimethylpolysiloxane polymers are
In the above formula, a is 10-114, b is 0-49, x is 388-402, y is 15-0.75, and the molecular weight of the group R is 1000-5000. Particularly preferred dimethylpolysiloxane polymers have the above formula where a is 14, b is 13, x is 249, and y is 1.25. Dimethylpolysiloxane polymers are usually prepared by dispersing them in volatile siloxanes. The silicone oil component thus contains 1-20% by volume of polymer and 80-99% by volume of volatile siloxane. The ideal silicone oil component consists of a 10% dispersion of polymer in volatile silicone. Examples of volatile siloxanes include volatile polydimethylcyclosiloxanes such as those having a viscosity of less than 5 mm ² /sec, such as Silicone 344 Fluid
(manufactured by Dow Corning) and volatile hexamethyldisiloxanes with a viscosity below 0.65 mm ² /sec, such as Silicone200 Fluid (manufactured by Dow Corning).
(0.65mm ² /sec). Particularly preferred silicone oil components are cyclomethicone and dimethicone copolyol, such as Silicone Q2-3252C Formulation Aid
(manufactured by Dow Corning) (DOW CORNING is a trademark).
Non-volatile silicone oils such as polydimethylsiloxane copolymers having a viscosity exceeding mm ² /sec, for example from 100 to 350 mm ² /sec, e.g.
Silicone200 Fluid (manufactured by Dow Corning) (100
mm ² /sec or more). Typically, the emulsion of the present invention contains 15 to 50% by weight, preferably 15 to 40%, ideally 20 to 30% by weight of the silicone oil component. The emulsions of the invention may also contain an emulsifier, which will typically be a nonionic liquid emulsifier with an HLB value of 1 to 7. The preferred emulsifier is
The HLB value will be between 2 and 6. Examples of stable emulsifiers are shown below. HLB value ARLACEL987 (sorbitan isostearate), Atlas 4.3 HOSTAPHAT KO 300N (mono-, di-, and triphosphate esters of oleic acid), Hoechst
2.3 IMWITOR780K (glycerol monoisostearate), Witco 3.7 BRIJ 92 (polyoxyethylene(2)oleyl ether), Atlas 4.9 triglycerol monooleate, PVO
International 4.0 ARLACEL 80 (Sorbitan Monooleate), Atlas 4.3 ARLACEL 83 (Sorbitan Sesquioleate), Atlas 3.7 ARLACEL 85 (Sorbitan Trioleate), Atlas 1.8 Decaglycerol Tetraoleate, PVO
International 6.0 Decaglycerol octaoleate, PVO
International 4.0 AMEROX or SIMULSOL2 (polyethoxylated (2) oleyl alcohol), Produits
Chimiques de la Montagne Noire 6.7 HOECHST 2721 (Polyglycol Sesquioleate) 4.0 The amount of emulsifier in the emulsion is from 0.5 to 10%, preferably from 1 to 5% of the weight of the emulsion. If the emulsion contains less than 0.5% emulsifier, even if an emulsion is obtained, it will not remain stable during storage. On the other hand, incorporating more than 10% emulsifier in the emulsion will not further improve the stability of the emulsion. The emulsions of the present invention also contain _C1 - _C4 alkanols. Examples of the alkanol include ethanol, n-propanol, iso-propanol, and n-butanol. A preferred alkanol is ethanol. The amount of alkanol contained in the emulsion is 5
-40% by weight, preferably 10-30%, most preferably 15-30%. The emulsion of the present invention may optionally also contain an electrolyte salt, the main effect of which is to increase the storage stability of the emulsion. Although it is possible to prepare satisfactory emulsions without the addition of electrolyte salts, temperatures may vary from below zero to over 40°C unless at least a small amount of electrolyte is included in the preparation. Under normal storage conditions in some factories, warehouses, stores, or homes, the stability of the emulsion may be unacceptable. Examples of suitable electrolytes are alkali metal and alkaline earth metal halides, sulfates, nitrates and carbonates or bicarbonates, which may be used in either anhydrous or hydrated salt form. The best electrolyte that can produce a healing effect when the emulsion is applied to injured skin is zinc sulfate, which is usually used as a heptahydrate salt. The amount of electrolyte salt contained in the emulsion is 0.1 to 10%, preferably 0.2 to 5% by weight. The emulsions of the present invention also contain water to prepare a suitable emulsion and to constitute a solvent for the water-soluble components in the emulsion. Usually 10-35%, preferably 15-35% based on the total weight of the emulsion
Contains water. Emulsions containing less than 10% water by weight leave the skin semi-dry. while 35
Emulsions containing water in an amount greater than 1.9% contain too much water and are difficult to actually use on the skin, causing early hydrolysis of alkyl lactate and making the product unstable. As previously mentioned herein, stable emulsions containing volatile polar organic liquids such as alkyl lactates and alkanols, which are essential components of emulsions, can be prepared using special silicone oil components as defined herein. can be successfully prepared using These emulsions exhibit no signs of syneresis when the temperature changes and at least 18
It can exist stably for several months or more. For maximum effectiveness in the topical treatment of acne, it is important that a substantial portion of the alkyl lactate does not undergo hydrolysis during storage, and certain precautions must be taken to this end. First of all, the total amount of water used when preparing the emulsion should not exceed 35% by weight to minimize premature hydrolysis of the alkyl lactate, as mentioned above. . Second, during the preparation of the emulsion the pH of the aqueous phase is preferably adjusted from 4 to 4 using a buffer.
Adjust to a value of 5.5. However, it will usually be impossible to determine the PH of the emulsion once it has been prepared. Third, a hydrophobic agent can be added to the emulsion to ensure separation of alkyl lactate and available water in the emulsion. In this way, the tendency of the alkyl lactate to hydrolyze during storage due to the access of water in the aqueous phase of the emulsion can be reduced. For the purpose of adjusting the pH of the aqueous phase during emulsion preparation, any cosmetically acceptable substance may be used, such as a buffer consisting of lactic acid and triethanolamine having a pH value of 4 to 5.5. It is preferable to use something. An example of a hydrophobic agent which may optionally be added to the emulsion to further enhance the stability of the alkyl lactate is hydrophobic silica having an organic content of 2 to 9%, preferably 2.5 to 8.5%. Specific examples of such hydrophobic silicas include AEROSILR805, which has less than 9% organic content, and AEROSILR812, which has less than 5% organic content, from Degussa. When using this hydrophobic agent, AEROSILR805
Alternatively, a hydrophobic agent such as R812 can be added to the emulsion in a proportion of 0.5 to 5% by weight, preferably 1 to 3% by weight. The emulsion of the present invention may further contain other generally cosmetically acceptable ingredients as appropriate without impairing the effectiveness or stability of the emulsion. These other ingredients include emollients, solvents, humectants, thickeners, moisturizers, antioxidants, surfactants, anti-inflammatory agents, and other therapeutic agents used in facial cosmetics. Contains preservatives, buffers, preservatives, antibacterial compounds, antibiotics, disinfectants, keratolytic agents, abrasives, fragrances or skin colorants. The above does not describe all examples of other components, and many others may be used.
Other examples include Mc
“Agents” by MC Cutcheon, 1976
Published by Publishing Co., New Jersey Publishing. In general, the amounts of the aforementioned other ingredients that may be used as appropriate will be those recommended by the manufacturer or supplier or those conventionally used by those skilled in the art, but depending on the nature of the emulsion and the functionality of the emulsion. The amount must not be such that it has a harmful effect on the These optional ingredients can balance the emulsion. The present invention comprises the silicone oil component defined herein, a nonionic liquid emulsifier with an HLB value of 1 to 7, an alkyl lactate (alkyl having 1 to 4 carbon atoms),
A method for preparing a water-in-oil emulsion suitable for topical use on the skin for the treatment of acne is also provided, comprising the step of making an emulsion from an alkanol (1 to 4 carbon atoms). According to a preferred embodiment of the preparation method of the invention:
Emulsions may be prepared from the following preparation steps: Prepare the aqueous phase from water and a buffer to bring the pH to 4-5.5, along with water-soluble ingredients other than the alkyl lactate and alkanol. An oil phase is prepared by mixing a silicone oil component and an emulsifier. An emulsion is prepared by slowly adding the aqueous phase to the oil phase at 20°C with vigorous stirring. The alkyl lactate and alkanol and optional flavor are added thereto with further stirring. The emulsion thus obtained is filled into a container such as a bottle with a lid. The emulsion of the present invention is a usually white, opaque cream that can be applied topically to the affected area of the skin with the fingers or with a suitable applicator. However, it is also possible to add a coloring agent to intentionally color the material. Repeated application to the acne lesions, for example twice a day, is sufficient to eliminate the acne or at least to regress the acne condition. The emulsions of the present invention are typically compressed tubes,
It is packaged in a suitable container such as a bottle or pot with a lid. The invention is illustrated by the following examples. Example 1 An anti-acne cream was prepared from the following ingredients. % Silicone oil component Silicone Q2−3252C Formulation Aid 29 Emulsifier Polyglycol Sesquioleate 2 Alkyl lactate Ethyl lactate 11.5 Alkanol Ethanol 21 Electrolyte Zinc sulfate (ZnSO ₄・7H ₂ O) 0.3 Other components Titanium dioxide 0.5 Vatufa (PH5.5) 2.5 Preservatives, Flavors, Antioxidants 2.5 Softeners 7 Water 23.7 100 This emulsion was stable for up to 16 months at storage temperatures up to 42°C. It was also stable after repeated freezing and thawing. This emulsion is used for topical treatment of acne. Example 2 An anti-acne cream was prepared from the following ingredients. % Silicone oil component Silicone Q2−3252C Formulation Aid 24 Emulsifier Polyglycol Sesquioleate 2 Alkyl lactate Ethyl lactate 11.5 Alkanol Ethanol 21 Electrolyte Zinc sulfate (ZnSO ₄・7H ₂ O) 0.3 Hydrophobic agent AEROSIL R805 3 Other components Titanium dioxide 0.5 Va (PH5.5) 2.5 Preservatives, Flavors, Antioxidants 2.5 Softeners 7.2 Water 25.5 100 This emulsion was stable for up to 16 months at storage temperatures up to 42°C. It was also stable after repeated freezing and thawing. This emulsion is used for topical treatment of acne. Example 3 A cream for treating acne was prepared from the following ingredients: % Silicone oil Silicone Q2-3252C Formulation Aid 28 Emulsifier Polyglycol Sesquioleate 2 Alkyl lactate Ethyl lactate 11.5 Alkanol Ethanol 21 Electrolyte Zinc sulfate (ZnSO _4.7H ) ₂ O) 0.3 Hydrophobic agent AEROSIL R805 1 Other ingredients Titanium dioxide 0.5 Buffer (PH5.5) 2.5 Preservatives, fragrances, antioxidants 2.5 Softeners 7.2 Water 23.5 100 The above emulsion can be stored up to 42℃ for up to 4 months. It was stable and stable to freeze-thaw cycles. The above emulsion can be used for topical treatment of acne. Example 4 A cream for acne treatment was prepared from the following ingredients: % Silicone oil ingredient Silicone Q2-3252C Formulation Aid 28 Emulsifier Polyglycol Sesquioleate 2 Alkyl lactate Ethyl lactate 11.5 Alkanol Ethanol 28.9 Electrolyte Zinc sulfate (ZnSO _{4.7H 2} O) 0.3 Hydrophobic agent AEROSIL R805 2 Other ingredients Titanium dioxide 0.5 Buffer (PH5.5) 2.5 Preservatives, fragrances, antioxidants 2.5 Softeners 7 Water 14.8 100 The above emulsion can be stored up to 42℃ for up to 3 months. It was stable and stable to freeze-thaw cycles. The above emulsion can be used for topical treatment of acne. Example 5 A cream for treating acne can be prepared from the following ingredients: % Silicone oil component Silicone Q2-3252C Formulation Aid 30 Emulsifier Sorbitan Isostearate 2.5 Alkyl lactate Methyl lactate 10 Alkanol Ethanol 10 Isopropanol 11 Electrolyte Zinc sulfate (ZnSO ₄ . 7H ₂ O) 0.3 Other ingredients Titanium dioxide 0.5 Buffer (PH5.5) 2.5 Preservatives, fragrances, antioxidants 2.5 Softeners 7.2 Water 23.5 100 The above emulsion is stable for several months at storage temperatures up to 42°C. It will also be stable to freeze-thaw cycles. The above emulsion can be used for topical treatment of acne. Example 6 A cream for treating acne can be prepared from the following ingredients: % Silicone oil component Silicone Q2-3252C Formulation Aid 25 Emulsifier Glycerol Monoisostearate 3 Alkyl lactate n-propyl lactate 12 Alkanol Isopropanol 18 Electrolyte Zinc sulfate (ZnSO ₄・7H ₂ O) 0.3 Other ingredients Titanium dioxide 0.5 Buffer (PH5.5) 2.5 Preservatives, fragrances, antioxidants 2.5 Softeners 6 Water 30.2 100 The above emulsion is stable for several months at storage temperatures up to 42℃. It will also be stable to freeze-thaw cycles. The above emulsion can be used for topical treatment of acne. Example 7 A cream for treating acne can be prepared from the following ingredients: % Silicone oil component Silicone Q2-3252C Formulation Aid 32 Emulsifier Glycerol (2) Oleyl ether 3 Alkyl lactate Isopropyl lactate 12 Alkanol Ethanol 12 Isopropanol 12 Electrolyte Zinc sulfate (ZnSO ₄・7H ₂ O) 0.3 Other ingredients Titanium dioxide 0.5 Buffer (PH5.5) 2.5 Preservatives, fragrances, antioxidants 2.5 Softeners 8 Water 15.2 100 The above emulsion is stable for several months at storage temperatures up to 42℃. Yes, and may be stable to freeze-thaw cycles. The above emulsion can be used for topical treatment of acne. Example 8 A cream for acne treatment was prepared from the following ingredients: % Silicone oil component Silicone Q2-3252C Formulation Aid 30 Emulsifier Sorbitan Monooleate 2.5 Alkyl lactate n-Butyl lactate 12 Alkanol n-Propanol 22 Electrolyte Zinc sulfate ( _ZnSO4 ) 7H ₂ O) 0.3 Other ingredients Titanium dioxide 0.5 Buffer (PH5.5) 2.5 Preservatives, fragrances, antioxidants 2.5 Softeners 5 Water 22.7 100 The above emulsion is stable for several months at storage temperatures up to 42°C. It will also be stable to freeze-thaw cycles. The above emulsion can be used for topical treatment of acne. Example 9 A cream for treating acne can be prepared from the following ingredients: % Silicone oil component Silicone Q2-3252C Formulation Aid 28 Emulsifier Sorbitan Sesquioleate 2 Alkyl lactate Ethyl lactate 12 Alkanol Ethanol 25 Electrolyte Zinc sulfate (ZnSO _{4.7H 2} O) 0.3 Other ingredients Titanium dioxide 0.5 Buffer (PH5.5) 2.5 Preservatives, fragrances, antioxidants 2.5 Softeners 7.2 Water 20 100 The above emulsion is stable for several months at storage temperatures up to 42℃, and can be frozen. It will also be stable to thaw cycles. The above emulsion can be used for topical treatment of acne. Example 10 A cream for the treatment of acne can be prepared from the following ingredients: % Silicone oil component Silicone Q2−3252C Formulation Aid 32 Emulsifier Sorbitan trioleate 2.5 Alkyl lactate Tert-butyl lactate 10 Alkanol Ethanol 10 Isopropanol 12 Electrolyte Zinc sulfate (ZnSO ₄ . 7H ₂ O) 0.3 Other ingredients Titanium dioxide 0.5 Buffer (PH5.5) 2.5 Preservatives, fragrances, antioxidants 2.5 Softeners 6.5 Water 21.2 100 The above emulsion is stable for several months at storage temperatures up to 42℃. It will also be stable to freeze-thaw cycles. The above emulsion can be used for topical treatment of acne. Example 11 A cream for treating acne can be prepared from the following ingredients: % Silicone oil component Silicone Q2-3252C Formulation Aid 29 Emulsifier Polyglycol Sesquioleate 2 Alkyl lactate Isopropyl lactate 11.5 Alkanol Isopropanol 21 Electrolyte Zinc sulfate (ZnSO _{4.7H 2} O) 0.3 Hydrophobic agent AEROSIL R812 Other ingredients Titanium dioxide 0.5 Buffer (PH5.5) 2.5 Preservatives, fragrances, antioxidants 2.5 Softeners 7 Water 23.7 100 The above emulsion is stable for several months at storage temperatures up to 42°C Will. It was also stable during freeze-thaw cycles. The above emulsion can be used for topical treatment of acne.

Claims (1)

[Scope of Claims] 1. A water-in-oil emulsion suitable for topical application to human skin for the treatment of acne, said emulsion comprising 2 to 30% by weight of water and an alkyl lactate (C ₁ -C ₄ ) or a mixture thereof. ; Has polyoxyethylene and/or polyoxypropylene side chains, molecular weight 10,000
~50000 and below structure (wherein R is [formula], a is 9 to 115, b is 0 to 50, x is 133 to 673, and y is 25 to 0.25) 15-50% by weight of a silicone oil component containing a volatile siloxane dispersion; 0.5-50% by weight of a non-ionic liquid emulsifier with an HLB value of 1-7
and 5-40% by weight of alkanols ( _C1 - _C4 ) or mixtures thereof, wherein said emulsion consists essentially of 10-98% by volume of an aqueous phase and 2-90% by volume of an oil phase. An emulsion characterized by: 2 Alkyl lactate is methyl lactate, ethyl lactate, n-propyl lactate, iso-propyl lactate, n- lactate
An emulsion according to claim 1 selected from butyl, iso-butyl lactate, tert-butyl lactate and mixtures thereof. 3 A dimethylpolysiloxane polymer having polyoxyethylene and/or polyoxypropylene side chains, a is 10 to 114, b is 0 to 49, x is 388 to 402, y is 15 to 0.75, 3. Emulsion according to claim 1 or 2, selected from polymers in which the group R has a molecular weight of 1000 to 5000. 4. A dimethylpolysiloxane polymer having polyoxyethylene and/or polyoxypropylene side chains is a polymer in which a is 14, b is 13, x is 249, and y is 1.25. The emulsion according to any one of the ranges 1 to 3. 5. The emulsion according to any one of claims 1 to 4, wherein the volatile siloxane is polydimethylcyclosiloxane. 6. The emulsion according to any one of claims 1 to 5, wherein the silicone oil component comprises 1 to 20% by volume of polymer and 80 to 99% by volume of volatile siloxane. 7 The emulsion has 5 to 20% by weight of ethyl lactate; the following structure having polyoxyethylene and/or polyoxypropylene side chains 15 to 40% by weight of a 10% by volume dispersion of tetradimethylcyclosiloxane in a dimethylpolysiloxane polymer (wherein R is [formula]); Nonionic liquid emulsifier with an HLB value of 1 to 7.
5% by weight; 10-30% by weight of an alkanol selected from ethanol, isopropanol and mixtures thereof; and 0.1-10% by weight of an inorganic salt, the emulsion comprising 50-90% by volume of an aqueous phase and 10-50% by volume of an oil phase. The first claim consisting of
The emulsion according to any one of items 6 to 6. 8. The emulsion according to any one of claims 1 to 7, further comprising hydrophobic silica having an organic content of 2 to 10%. 9 Claims 1 to 8 which are creams
The emulsion according to any of paragraphs. 10 Water and alkyl lactate (C ₁ - C ₄ ) or a mixture thereof 2 - 30% by weight; Has polyoxyethylene and/or polyoxypropylene side chains, molecular weight 10000
Structure of ~50000 and below (wherein R is [formula], a is 9 to 115, b is 0 to 50, x is 133 to 673, and y is 25 to 0.25) A silicone oil component containing a volatile siloxane dispersion of
15-50% by weight; nonionic liquid emulsifier with HLB value 1-7 0.5-
10% by weight; and 5-40% by weight of alkanols ( _C1 - _C4 ) or mixtures thereof, consisting essentially of 10-98% by volume of an aqueous phase and 2-90% by volume of an oil phase. A method for producing a water-in-oil emulsion suitable for topical application to human skin for the treatment of acne, the process comprising preparing an oil phase by mixing a silicone oil component and a non-ionic liquid emulsifier, buffered to a pH of 4 to 5.5. homogenizing the oil phase with an aqueous phase containing an aqueous solution of a water-soluble component other than the alkanol and alkyl lactate; followed by mixing and blending the alkyl lactate and the alkanol to prepare a water-in-oil emulsion; A method consisting of.